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Environmental/Regatta Buoy: Telemetry and Configuration

1. eee ene 98 Bibliography 99 List of Figures 1 1 Picture of imysell lt 0 6o is owed whee ed ede a 2 EO Booy Ml soc tooo sis rea de 3 2 1 General architecture of an autonomous buoy Bl 7 q ete eee eee ee Gee 9 See eee eee eee eee eae ee ea oe oe 9 ANN 2 au ap soo oes Boe eb Ree ee eee oe be ee Os 16 32 LOA ONO s amp Bae e ee bbe VEER EES eee OR ke Se 17 Dee e eee eens ee cat ape oe 19 3 4 LED indicating the network activity 20 do Mconhe comimandh se ss s sessies da a SG aw Oe ee sm ES 20 3 6 Raspi config menu l eee 21 3 7 Raspi config menu 2 bok we Gun hee Owe Ew Ow He oe ww EO 21 3 8 Raspi config menu 3 21 TE E gerando 22 3 10 USB to USB cable 2 o e 23 3 11 Crossed cable layout 4 o o 23 3 12 USB to mini USB cable 6 24 dla CIP nO oa rada AAA 25 aan sara a 27 3 19 SUPERSTAR ILL sarera sseni daaa E te eas 27 4 1 Raspbian Logo BI 29 feo Go a Rs a ED a E Ea Ra 31 4 3 Setup ssh in terminal ee 32 TAIANA 33 4 5 Printscreen of the coolTerm setup 34 AE en sd 4 37 vi LIST OF FIGURES a a 40 J 43 EE En an 44 NR EA ne ndo aes 46 ara a aa ad 47 ano oa sous 49 ys a we eo we 50 6 1 General architecture of the buoyl 0 2 2 52 6 2 Architecture of the master module 53 ee 55 6 4 Flowchart for sending to the STM3
2. Inputs Hexadecimal string Outputs Hexadecimal string In the code beneath the actual function can be found There can be seen that the binascii crc32 function is used to calculate the CRC32 checksum 30 If the result of this function is negative the minus sign is deleted and the two s complement of the result is taken def makeChecksum dataHex makes a checksum of all the seperate hex numbers dataString binascii a2b hex dataHex return to ascii numbers checksum binascii crc32 dataString 0 if hex checksum 0 checksumHex hex checksum 1strip 0x checksumbintemp bin int checksumHex 16 1strip 0b checksumbin checksumbintemp if len checksumbintemp lt 32 i 0 for i in range 0 32 len checksumbintemp checksumbin 0 checksumbin checksumbin twoscomp checksumbin checksumHex hex int checksumbin 2 1lstrip 0x else checksumHex hex checksum Istrip Ox get rid of the 0x before the hex number if len checksumHex 7 checksumHex 0 checksumHex return checksumHex rstrip L 78 CHAPTER 6 RASPBERRY PI IMPLEMENTATION 6 13 22 putinRightQueue Table 6 23 Info putInRightQueue function Description Puts the given Command in the right priority Queue Inputs Command Outputs none 6 13 23 interruptedQueueHigherPriority Table 6 24 Info interruptedQueueHigher Priority function This function returns 1 if the priority of the command in the interruptedQueue is
3. Raspberry Pi S end a Comm an O t data quest data finished Figure 5 6 Slave gets a wrong message STM32F3 4T 48 CHAPTER 5 APPLICATION PROTOCOL e The message that arrives at the STM32F3 Discovery is incorrect and the STM32F3 Discovery sends a wrong command message back The Raspberry Pi sends a message ok back to the STM32F3 Discovery The Raspberry Pi sends the command back to the STM32F3 Discovery If the command is now ok The Raspberry Pi gets a message ok back The rest of this situation is the same as the first situation 5 6 4 Slave to Master Error Message Figure 5 7 represents when an error message is send from the ST M32F3 Discovery to the Raspberry Pi As can be seen in the Figure when the program gets an error between two data packages a message ok is send back to the STM32F3 Discovery The error message is than send to the base station so this base station immediately knows there is an error The rest is almost the same as the first situation 5 6 5 Master to Slave Wrong Data Package Message In Figure 5 8 represents the arrival of a wrong data package If a data package is received in the Raspberry Pi from the STM32F3 Discovery but the data package is not correct the program sends a wrong data message back from the Raspberry Pi to the STM32F3 Discovery The STM32F3 Discovery sends the data back again then The rest is the same again as situation 1 5 7 Conclusion
4. a ARA smaller or equal than the one that is given as a parameter Inputs integer priority 1 the priority of the command in the interruptedQueue is smaller or equal to the given priority O the priority of the command in the interruptedQueue is bigger than the given priority Outputs 6 13 24 main Table 6 25 Info main function Description This starts all the threads Inputs none Outputs none The actual python code is given in the appendix In this report there is only given an overview of which functions there are what they do and how they do it If you want to see the real implementation in python you can look at the actual code of the program Every function in the code is also commented to make it as understandable as possible for everybody that reads it 6 14 Simulation of the STM32F3 Discovery In order to test the code of the Raspberry Pi there had to be made a python file that simulates in a simplified way the behaviour of the STM32F3 Discovery This is a simple program that can also be found together with the other python files 6 15 CONCLUSION 79 6 15 Conclusion The analysis of the implementation of the project inside the master module the Raspberry Pi was presented in this chapter Chapter Base Station Implementation In the previous section there was discussed a lot about how the functionalities were implemented inside the Raspberry Pi Of course the mission is to make a buoy where you c
5. e Thin film elements manufactured using materials and processes similar to those employed in the manufacture of integrated circuits A platinum film is deposited onto a ceramic substrate which is then encapsulated This method allows for the production of small fast response accurate sensors 17 3 5 1 3 Pressure Load sensors are used to measure this value A load cell is a transducer that is used to convert a force into an electrical signal This conversion is indirect and happens in two stages Through a mechanical arrangement the force being sensed deforms a strain gauge The strain gauge measures the deformation strain as an electrical signal because the strain changes the effective electrical resistance of the wire A load cell usually consists of four strain gauges in a Wheatstone bridge configuration Load cells of one strain gauge quarter bridge or two strain gauges half bridge are also available The electrical signal output is typically in the order of a few mV and requires amplification by an instrumentation amplifier before it can be used The output of the transducer can be scaled to calculate the force applied to the transducer 3 5 2 Anemometer The chosen wind sensor in this project is a Mechanical one seen in Figure It consists of a sort of propeller and a vane The wind speed is determined by counting the number of rotations per time unit We count the pulses A preci sion potentiometer is used to check the wi
6. has the incoming command a higher priority No Interrupt Data Figure 6 9 Flowchart for the control thread 6 12 DEFAULT SETUP 69 The interruptData function starts with sending a Stop message to the STM32F3 Discovery The STM32F3 Discovery will now stop with sending data Only the current data package will be finished The state is changed to 7 This means the STM32F3 Discovery communication threads will wait for a message ok from the STM32F3 Discovery without waiting for data after this The next thing is analysing the last data package The thread will look at the time and date of this last data package and remember this It takes this data and time and changes the beginning date of the message that was being processed After the message has been modified it is put in the interrupted queue The reason the program changes the date of the message is because it could already have a lot of data received from the STM32F3 Discovery for this com mand So when the program now takes the message again out of the interrupted queue it will only ask for the data that comes after the last data package it al ready received 6 12 Default Setup The default setup is a python file where all the default parameters are defined Table 6 2 contains an overview about the different parameters 70 CHAPTER 6 RASPBERRY PI IMPLEMENTATION interrupt data send a stop command to the STM32F3 make the stateSTM 7 get the time and
7. There should noted that in the actual program these priorities are customiz able The implementation will make sure you can add or remove commands from a certain priority This was done in the defaultsetup file 5 4 CRC32 Checksum CRC32 is a 32 bit Cyclic Redundancy Check code used mainly as an error de tection method during data transmission If the computed CRC bits are different from the original transmitted CRC bits then there has been an error in the transmission If they are identical there can be assumed that no error occurred there is a chance 1 in four billion that two different bit streams have the same CRC32 The idea is that the data bits are treated as a data polynomial and the CRC bits represent the remainder of the division of the data polynomial by 42 CHAPTER 5 APPLICATION PROTOCOL a fixed known polynomial called the CRC polynomial 27 The CRC32 polynomial is c z 1 x x xr x xxl px OE A b x needs to be found so that d x a x c x b x d x is our data b x is our CRC32 and we don t care about a x Or in other words b x d x mod c x The CRC32 is widely used checksum for example zip files use this checksum and it is included in the binasci library in python Because the result has actually 33 bits one bit says whether the checksum is positive or negative the checksum needs to be modified a bit so it is only 32 b 4 B When the checksum is negative the function takes the two
8. In the this section the protocol that was designed by the previous students was discussed T he section handled the evolution of the protocol in order to overcome some obstacles we had with the old declaration of the protocol changes that were made to improve the protocol like additions or removals of some functions On the basis of some examples the protocol should be clear now for everyone who read this section The next chapter will talk more about the implementation of the protocol in a multi threaded environment 5 7 CONCLUSION base station Raspberry Pi Send a Comman tor data equest ata finishe Message ok d Figure 5 7 Slave reports an error to master STM32F3 49 50 CHAPTER 5 APPLICATION PROTOCOL base station Raspberry Pi STM32F3 Figure 5 8 Master gets a wrong data package message Chapter 6 Raspberry Pi Implementation In this section the implementation of the protocol and the functionalities in the Raspberry Pi and im the base station are going to be discussed The programming language that was used is python This scripting language was discussed earlier in the report 6 1 Introduction To implement the protocol in the Raspberry Pi there will be 5 main threads e 1 thread to receive commands or data from the STM32F3 Discovery e 1 thread to send commands or data to the STM32F3 Discovery 1 thread to receive commands from the base station 1 thread to send commands or data to the base
9. Is there a message coming in Is the message quit make the variable Yes quit 1 akeCommand Put the command in the incomingQueue Is the return zeroCommand Send a wrong Yes command to the base station Send a message ok to the base station No is the return wrong data Is the return Is openSer 0 message ok P Y Yes Yes T make Send an STM Not aitingMessageOk waltingMessageOk 0 make Connected error to ula hos and wrongData 1 the base station 1 baseStationTimeout O Figure 6 7 Flowchart for receiving from the base station 6 11 CONTROL THREAD 67 startBaseStationSending quit the program is the dataQueue empty Yes get the message out of the queue and send itto the base station make waitingMessageOk 1 make is wrongData wrongData 1 and send the message again is waitingMessageOk or timeout Yes put the message back in the queue and wait is baseStation Timeout gt 2 YesP until the base station is ready again No Figure 6 8 Flowchart for sending data to the base station 68 CHAPTER 6 RASPBERRY PI IMPLEMENTATION Start Control thread No quit the program is openSer 0 new string in the incomingQueue Yes take the command out of the incomingQueue Put the command in the right queue No is stateSTM 4 or 5
10. TCP unicast and UDP multicast are supported to transmit data point to point and point to multipoint to an un known number of listeners located in the vicinity of the buoy The code that is used in the base station program to receive multicast data can also be used in other hardware components in the future There was also a base station module created that can successfully commu nicate with the buoy and that can display and store data information from the buoy From the base station the user can start and stop different kinds of modes depending on his needs A default setup file was created so that users can add different sensors This is useful for the future when different sensors than the ones we have now are added As long as the message request packages have the same structure as defined in the protocol they will be handled correctly This file allows configuring other parameters such as different types communication the serial connection or the TCP IP connection A default mode can also be defined that will run at start up 97 98 CHAPTER 9 CONCLUSIONS 9 2 Future Developments Due to problems with the data logging subsystem and to the lack of time there was no time left to really test the buoy in the field Since the Beaglebone Black was unavailable the telemetry and configuration subsystem was implemented on a Raspberry Pi This should not pose problems since the BeagleBone also supports python This migrati
11. WIND DIRECTION Al WATER DEPTH 45 WATER CONDUCTIVITY 49 WATER TEMPERATURE 31 Does this mode broadcast 0 no iil yes O Give in the time interval between two measurements hh mm ss ss 00010000 give in the protocol there is only on protocol at the moment this may be implemented later O current protocol 0 4 4 Protocols 4 4 1 TCP IP Network Protocol The TCP IP protocol is the networking model and a group of communications protocols used for the Internet and similar networks It consists of the Trans mission Control Protocol TCP and the Internet Protocol IP which were the first networking protocols that were defined It is occasionally known as the DoD model because the development of the networking model was funded by DARPA an agency of the United States Department of Defence TCP IP provides end to end connectivity specifying how data should be for matted addressed transmitted routed and received at the destination This functionality has been organized into four abstraction layers which are used to sort all related protocols according to the scope of networking involved From lowest to highest the layers are the link layer containing communication tech nologies for a single network segment link the internet layer connecting hosts 36 CHAPTER 4 PROJECT DEVELOPMENT TOOLS across independent networks thus establishing internet working the transport layer handling ho
12. queue8 that are received from the base station to send to the STM32F3 FIFO Each queue represents one priority level the interruptedQueue represents a queue where interrupted message are put in This is the only queue with Last In First Out interruptedQueue configuration because messages with a higher priority were added UFO later to the queue If Raspberry Pi gets normal data packages from the STM32F3 they dataQueue FIFO are put in the dataQueue until they can send to the base station If the Raspberry Pi gets data packages from the STM32F3 that are dataBroadcastQueue meant to be broadcasted they will be put in the FIFO dataBroadcastQueue until raspberry pi has send them The incoming messages from the base station are first put in the incomingQueue incomingQueue until the control thread puts them in the right FIFO priority queue 6 13 4 Starting Threads There has been given an example here on how to start a thread in python If we look at for example the code below the start up of the thread baseStationSending 6 13 COMPLEMENTARY CLASSES 73 can be seen The first thing the program does is making a thread object After this there has to be made sure the daemon option is true This means that all threads will be terminated when the main thread terminates The daemon option is actually not necessary but it makes testing a lot easier Otherwise you have to quit the terminal window every time to stop
13. the Stor X data acquisition and download schedules and the connection to the outside world via the radio modems To provide power there is a solar panel and a Rutland 913 wind generator The shore to buoy communication uses a pair of RM9600 radio modems manu factured by Radio Data Technology Ltd producing 500 mW of radio frequency RF power and connected to a 3 dB 50 V collinear aerial 12 2 4 3 Implementation of Embedded System for Autonomous Buoy This project was done in the Department of Electronics Engineering Korea Uni versity in Seoul They developed a Autonomous Buoy which is composed of an embedded system OPC Optical Particle Counter and CTD Conductiv ity Temperature Depth sensors to observe underwater environment The au tonomous buoy is controlled by an embedded system composed of field programmable gate array FPGA and high performance CPU which is designated to perform Image signal processing data compression power management and satellite com munication So like in our project there is also a master slave configuration between the CPU and the FPGA The autonomous buoy has vertical movements in the water There are three types of movements e Sinking motion for collecting data e Stay at a certain undersea level and drift without up and down motion e Move up to collect data from sensors and transmit data to satellites at the sea level The data flows from the FPGA through FIFO to the CPU
14. the sending part will be explained a little bit more A general flowchart can be found in Figure 7 1 The flowchart starts with a block that will print all the different options This block will take care of knowing which commands can be send by the base station to the Raspberry Pi and it will let the user choose which command he wants to send The user will now give in a suitable option The program will then decide whether it need more information regarding the choice of the user Some command require some extra parameters that need to be given in If all the information has been gathered the program will make the right command package and it will send this command to the Raspberry Pi After this this thread will wait until it gets a signal from the receiving thread that a message ok was delivered by the Raspberry Pi If this is the case another message can be send f 4 Receiving from the Raspberry Pi In this section the receiving thread will be discussed A general overview can be found in Figure This receiving thread handles only the messages that were send directly to the base station the receiving of multicast messages are handles by another thread The first thing that is done is checking if there is a incoming message from the Raspberry Pi If this is the case the program will check if it is a message ok that was received If the message was indeed a message ok the thread has to check if the variable waitingMessageOk is equal to o
15. about Portugal and their food traditions xl xil GLOSSARY I thank Mr Manuel Silva to lend me his USB hub Last of all I want to thank Mr Pedro Rocha from the LSA department for helping and providing me with components and for helping me with all sorts of problems Chapter 1 Introduction 1 1 Presentation My name is Laurens Allart and I am in the final year of the Master of Science in Electronics Engineering from KU Leuven Campus Gent in Belgium In the middle of February 2014 I arrived at the Instituto Superior de Engenharia do Porto to do an Erasmus exchange program to finish my studies I did this by doing my Master Thesis in the form of an Erasmus project I am here to do this project and also to follow two additional courses 1 chose Porto because of their interest in robotics I didn t know a lot about Portugal and I wanted to get to know the country some more 1 2 Motivation I chose the Instituto Superior de Engenharia do Porto because of the existing thesis proposals which were focussed on autonomous systems This is a topic that interested me to get to know how to make objects more autonomous This is the main reason why I chose the autonomous buoy as subject for my thesis The reason I did the Erasmus exchange project is because I think it was a unique opportunity I learned a lot in my time here in Portugal school related things but also non school related think I liked exploring more of the world than my h
16. base station te behandelen en een prioriteit toe te kennen Hij moet informatie kunnen vragen aan de slave module en in regatta mode moet hij real time data kunnen broadcasten naar andere modules De communicatie tussen de master unit en het base station en de master unit en een autonome boot moet gebeuren aan de hand van een draadloze verbinding de communicatie tussen de master module en de slave module gebeurt aan de hand van een seri le connectie De boei heeft momenteel twee beperkingen i de maximale lading bedraagt veertig kilogram en ii ze kan enkel gebruikt worden in rivieren of dicht bij de kust door de beperkingen die de keuze van de gebruikt draadloze communicatie technologie oplegt Contents Contents ist of Figures ist of Tables Glossary Acknowledgments 1 2 Introduction TEE aaa a Aaa ET TREN E ES ES AD nee ee eee a 1 4 2 Environmental Model ccccccl aaa RE Da a State of The Art eee nde den Sd Sa A a amada hae eee bate ee ean da eee DO SONO bia rapa ELES ee ee ee ee 2 3 1 Surface Sensorsl 23d Windi on Ge eG ee SS RS a 2 3 1 2 ECMPOrTa LUTO cassia He woe ode ee 2 3 1 3 Air Pressure 0 0 00 2 200048 FEET 2 3 1 5 Relative Humidity 2 3 1 6 Solar Radiation vil IX xl 11 CONTENTS 2 3 2 Oceanographic SensolSt e ee 10 Zalman asadas 10 2 3 2 2 Chemical Subst
17. can make a command object out of a string Table 6 3 displays the different properties of this class 72 CHAPTER 6 RASPBERRY PI IMPLEMENTATION Table 6 3 Properties of class command properties explanation ID ID of the command data length data length first date and time this is equal to zero if there is no data included in the date 1 command If the command is mode on the parameters in the data part are equal to data 1 second date and time If the command doesn t have a second date this is equal date 2 to zero commandHex The complete hexadecimal string of the whole command 6 13 2 Class Data The class Data is a class that can make a data object out of a string Table 6 4 shows the different properties this class Table 6 4 Properties of class data properties explanation ID ID of the different sensors from which data is included in this message This can ea be an array of ID time The time of the measurement data data of the different sensors This can be an array of data strings hexString The complete hexadecimal string of the whole data package o 6 133 Queues In our program there are a lot of queues in order to maintain the priorities and to put data in A list with all the queues is given in Table Table 6 5 Implemented queues queue name function type queuel until queue8 represent the waiting queues for commands queuel
18. data transmission between different devices by means of a secure globally free Standard system for communication via mobile telephones incorporating digital technology CSM extension for unswitched or packaged data transmission Standard defining the physical level and control of medium access of WPANs with low data transmission rates specification of a set of high level wireless communication protocols for use with low consumption digital radios based on WPAN standard IEEE 802 15 4 2 3 1 Surface Sensors 2 3 1 1 Wind 11 54 300 Mb s Class 1 100m Class 2 15 20 m Class 3 1 m Dependend on cellular network service provider Dependend on cellular network service provider The Davis Anemometer is the device that the previous students have chosen to use as the wind sensor for our project It can measure wind speeds and wind direction It can withstand very strong winds but it can also detect little breezes 2 3 1 2 Temperature These sensors measure the temperature of the air in C or in F 2 3 SENSORS 9 Figure 2 2 CTD package sensor Figure 2 3 Anemometer 2 3 1 3 Air Pressure These sensors measure the air pressure in mb 2 3 1 4 Precipitation Precipitation is any product of the condensation of atmospheric water vapour that falls under gravity It is measured in millimetre 10 CHAPTER 2 STATE OF THE ART 2 3 1 5 Relative Humidity Relative humidity is the rat
19. hull plus the steel structure can be found in Figure The structure was made for stabilization to attach sensors as an antenna and to make the buoy higher and more visible The two students who worked on the project from September 2013 till the beginning of 2014 were mostly working on the research of the electronics that 1 4 PROJECT DESCRIPTION 3 Figure 1 2 Buoy had to be in the buoy There were also some sensors already available in the LSA laboratory They divided the electronics part into two different things A master component that would handle all the communication parts like taking in requests handle these request manage data that was received The other component is a slave module that is responsible for collecting and saving data on a SD card These students defined which hardware components will be used for these different modules and which communication technologies They were also responsible for the design of a new protocol that could be used to communicate between the different hardware modules like the master the slave and the base station This paper will go deeper into the communication part of the project and especially on the implementation in the master hardware module Also a pro gram for the base station was implemented and will be discussed in this report Where the previous students were mostly focussed on the research of different techniques to do this this report will be more about the actual
20. master control unit and boat communication is wireless the master and the slave units communicate over a serial connection The buoy has currently two limitations 1 the maximum payload is 40 kg and ii it can only be used in rivers or near shore due to the distance limitation of the chosen wireless communication technique Samenvatting Het monitoren van de geografische omgeving is essentieel om belangrijke beslissin gen te nemen in zowel wetenschappelijke middens als in de industrie Omdat water in het bijzonder noodzakelijk is voor de mogelijkheid tot leven en omdat het grootst deel van het aardoppervlak bestaat uit water is het van groot belang weersomstandigheden en water gerelateerde parameters te bestuderen in gevoelige ecosystemen zoals oceanen lagunes meren en rivieren In van de meest voorkomend methodes om water te bestuderen is het gebruik van boeien Dit werk zal dan ook voort bouwen op een deel van een groter project dat tot doel heeft om een autonome boei te ontwikkelen voor wetenschappelijk onderzoek die 2 verschillende modes kan hanteren Een mode die zorgt voor het monitoren van de omgeving en een mode die zich gedraagt als een regatta beacon Als gevolg hiervan heeft de boei twee belangrijke toepassingen Het verzamelen en opslaan van data en het bieden van assistentie in een autonome boten race Het project werd twee jaar geleden gestart met een groep van vier interna tionale studenten Zij hebben de fysische s
21. mini USB cable 2013 cited at p v 24 7 NovAtel Superstar II User Manual 2005 cited at p v 27 8 Raspbian Raspbian logo 2013 cited at p v 29 9 python tutorial Python logo 2013 cited at p v 31 pm Harish Kotra Raspberry Pi World s Cheapest Computer Sold Over 1 5 Million Units 2013 cited at p vii 18 Carrilo Garcier M Popp H J Toma D M St tzle M Autonomous Me teorological Buoy 2009 cited at p 11 E al 12 Ll T J Smyth R Fishwick C P Gallienne J A Stephens A J Bale Tech nology Design and Operation of an Autonomous Buoy System in the West ern English Channel 2010 cited at p 12 13 Kyung Woon Lee Ui seok Jeong Joon Young Yang Ho Kyung Jun Jung Ho Park Implementation of embedded system for autonomous buoy 2011 cited at p 13 99 100 BIBLIOGRAPHY 14 ST STM32F3 Series 2014 cited at p 22 15 Wikipedia Sensor 2014 cited at p 24 16 Wikipedia Electrical conductivity meter 2013 cited at p 25 17 Omega What Are Pt100 Pt500 and Pt1000 Temperature Sensors 2003 2014 cited at p 26 118 Wikipedia Load cell 2014 cited at p 26 19 Raspbian Raspbian 2013 cited at p 29 20 ChibiOS ChibiOS RT Homepage 2014 cited at p 30 21 Wikipedia Python programming language 2014 cited at p 30 22 Wikipedia X Window System 2014 cited at p 31 23 MacOSForge XQuartz 05 2014 cited at p
22. output window There can be 8 2 USE CASES 93 chosen to give along with the parameters one date or two dates In this example one is chosen After this the date has to be given in in the form hhmmssssDDM MYYYY This represents the hours minutes seconds hundreds of seconds day of the month the month and the year The command will then be checked if it is a valid command If this is the case the base station will send the message to the Raspberry Pi and wait for a message ok Once we received the message ok the user can choose a new request Once the data if the first message arrives it will be displayed on the screen and a message ok will be send back to the Raspberry Pi 8 2 2 Master to Slave Broken Communication The second situation is one where the STM32F3 Discovery doesn t respond to requests The output for the base station communication threads can be found below Listing 8 4 output base station communication Starting baseStation communication Listening for connections from a base station Can t make contact with the base station We will try again in 10 seconds Listening for connections from a base station connection with client lt socket socketobject object at 0xb695d8b8 gt at address 192 168 1 12 56741 received a command from the base station Command 2431ce0112000000240520142aa3d33aa0 message ok send back to the base station command in queue6 d
23. which performs the data correction and ISP Image Signal Processing When the buoy comes up the sea surface it transmits the saved sensor data with the GPS position information of the buoy to users by ORBCOMM satellite communication Satellite data com munication is realized by ORBCOMM and satellite communication modem used 2 5 CONCLUSION 13 94000 of QUAKE GLOBAL transmitted GPS positional information with other collected data to users and is controlled and communicated by using RS 232 of main controller To save power consumption this system uses sleep mode of the main controller when the buoy is drifting in the sea 2 5 Conclusion When we look at the other projects we see a lot of similarities between them and our autonomous buoy project Most of them also use a master CPU who controls and manages the system and the communication and then a controller that takes care of the sensors The sensors that are used depend on the application The two modes of our buoy are unique since we didn t find any project that has the same possibilities to switch the mode Chapter 3 Available Equipment In this section the different hardware we had at our disposal will be discussed They will be explained one by one 3 1 Hull and Steel Structure The design and execution of the hull was one of the assignments of the first group that worked on the project In Figure 3 1 you can see a picture of the hull without the steel structure The m
24. 0 1200 plus various PAL NTSC standards and NTSC standards Audio Outputs 3 5 mm jack HDMI 3 5 mm jack HDMI FS audio also potentially for audio input Onboard Storage SD MMC SDIO card slot 3 3V SD MMC SDIO card slot 3 3V card power support only card power support only Power Source 5V via MicroUSB or GPIO SV via MicroUSB or GPIO header header Arch Linux ARM Debian Linux Arch Linux ARM Debian Linux Fedora FreeBSD NetBSD Plan 9 Fedora FreeBSD NetBSD Plan Raspbian OS RISC OS 9 Raspbian OS RISC OS Slackware Linux Slackware Linux 85 60 mm x 53 98 mm 3 370 in 85 60 mm 53 98 mm 3 370 in 2 125 in 2 125 in weight Esteo 1691602 Memory RAM 256 MB shared with GPU 512 MB shared with GPU USB 2 0 Ports 1 direct from BCM2835 chip 2 via the built in integrated 3 port USB hub Pro justo josse Network Adapter NONE 10 100 Ethernet 8P8C USB adapter on the third port of the USB hub 3 2 3 Setting up the Raspberry Pi The user first needs to plug an Ethernet cable in the Raspberry Pi and the laptop and supply power by connecting the micro USB on the Raspberry Pi to one of the USB ports on the computer or to the nearest outlet This can be seen in Figure After the Raspberry Pi was powered on the user has to wait a couple of seconds When the LED indicating the Internet goes out and then goes back on again the connection protocol between the computer and the raspberry is done and
25. 232 SD SDIO SDRAM SoC SSH TCP TDMA USB Wifi WiMAX WPAN WOM WSN GLOSSARY Description Instituto Superior de Engenharia do Porto Image Signal Processing Type of nitrate sensor Jackson Turbidity Unit Katholieke hogeschool Katholieke Universiteit Leuven Liquid Crystal Display Low Noise Amplification Laborat rio de Sistemas Auton mos MultiMediaCard Moving Picture Experts Group National Marine Electronics Association National Television System Committee Nephelometric Turbidity Units Optical Particle Counter Orbital Communications Corporation Phase Alternating Line Personal Computer Radio Corporation of America Renaissance Semiconductor for Advanced Solu tions Radio Frequency Raspberry Pi Foundation Recommended Standard 232 Secure Digital Secure Digital Input Output Synchronous Dynamic Random Access Memory System on a Chip Secure Shell Transmission Control Protocol Time Division Multiple Access Universal Serial Bus Wireless Fidelity Worldwide Interoperability for Microwave Access Wireless Personal Area Network Water Quality Management Wireless Sensor Network Acknowledgements I would like to take this opportunity to thank all the people and institutions that were involved in this project I am very glad I got the chance to get this amazing opportunity It really was an experience that I will remember for the rest of my life First of all I would like to thank the Kaho Sint L
26. 2F3 Discovery 61 pee eee enn e eee ee wee ene eee ee es 62 6 6 Flowchart for receiving from the STM32F3 Discovery 64 se 66 Raras 67 6 9 Flowchart for the control thread 68 6 10 Flowchart for the interrupt data function 70 1 1 Sending messages to the Raspberry Pif o oaa aaa 84 7 2 Receiving messages from the Raspberry Pil 85 7 3 Receiving broadcast messages ee 86 List of Tables 2 1 Communication technologies 2 8 3 1 Specification of the Raspberry Pi IO 18 3 2 Conductivity of common solutions 25 5 1 All the possible commands 2 000002 ee ee 38 5 2 Data specifications of the mode on command 39 5 3 Priorities of the different messages 000 Al 6 1 Global variables of the program 004 56 6 2 Default setup parameters a aoa a a a a a fal 6 3 Properties of class command 0 0002 eee 72 6 4 Properties of class datal o 12 6 5 Implemented queuesl e 72 O ee 73 eee ee eee Ene ss ni nani 73 a eee 74 as 74 aaa a 74 a eee 74 aa 75 EEn 75 corro 75 aaa 75 ias 76 EEn 76 EEn 76 6 19 Info interruptData function 0 2 0 0 00848 76 6 20 Info onescomp function 2 2 77 6 21 Info twoscomp function a a 77 vil vili L
27. 3 Data STM32F3 Discovery It also includes a part of the main control thread The first thing here are the states of the protocol Because threads run simul taneously parallel with each other there needs to be some kind of state machine in order to keep the sequential order of the protocol With this state machine all the threads know in which state the protocol is located This will be discussed first and there will be some examples afterwards A visual representation of the state machine can be seen in Figure 6 3 When nothing is pending the state is O In this state the program is just waiting until there is a command coming in from the base station When this is happening there are two choices after the command is analysed e When it is a command that needs information or data from the STM32F3 Discovery like for example wind speed water temperature or coordi nates the new state will become 1 e When it is a command that doesn t need data from the STM32F3 Discovery like for example mode on or mode off the new state will become 2 54 CHAPTER 6 RASPBERRY PI IMPLEMENTATION After the command was actually send over the serial connection the states will become respectively 3 or 7 as can be seen in Figure In both states the program will wait until there is a message ok coming back from the STM32F3 Discovery If this is the case state 7 will go back to state O State
28. 3 will become state 4 and will wait for data When a data package is received while the state is equal to 4 the state will become 5 But when a message ok is send back to the STM32F3 Discovery to let him know the data package was received the state will go back to state 4 When the program receives a dataFinished command instead of a data package the state will turn into 6 This means all the data was received After the program sends a message ok back the state will return to zero again and the program can wait for the next command There are also some special cases where there wasn t received what was expected e When the program receives an error from the STM32F3 Discovery it will look if there is a message that is currently processing If there is one this message will be saved in the interrupted Queue and the state will be set back to zero after a message ok was send back to the STM32F3 Discovery e When there is data coming in when it wasn t expected the Raspberry Pi will still give it to the base station It could be that there is still data coming in after an error or there could be a broadcast data message coming in So the state will not be changed when there was unexpected data received Only a message ok is send back e When there is data coming in but the data message is not correct the program sends a wrong data message back to the STM32F3 Discovery The state matching just stays in the same state e Th
29. 31 24 Wikipedia Secure Shell 2014 cited at p 32 25 chiark greenend PuTTY A Free Telnet SSH Client 2014 cited at p 33 26 Wikipedia Internet protocol suite 2014 cited at p 36 27 hibaman hotmail com CRC32 Maths and programming 2003 cited at p 42 28 Python org TCP Communication 2012 cited at p 58 82 29 PyMOTW Multicast Python Module of the Week 2014 cited at p 59 82 30 Python org binascii Convert between binary and ASCII 2014 cited at p 77
30. 40520143153656e736f723a20576953702c204d45532031002ac7fe9c11 not broadcast data received message ok send to the STM32F3 received a message from the STM32F3 24906f002ad713dab6 datafinished received from the STM32F3 All data was received succesfully The output of these threads starts with the initialization of the serial connec tion The next thing is sending the default mode on message If the STM32F3 Discovery receives this message it will send a message ok back This can be seen in the output Once this initialization work is all done the Raspberry Pi can get the message we put earlier in the queue6 out of the queue and send it to the STM32F3 Discovery The program then waits again for a message ok When we get the message ok from the STM32F3 Discovery the Raspberry Pi can wait for the requested data Once it receives a data package the Raspberry Pi will also check if it isn t a broadcast message The program will put the data package in the dataQueue and it will send a message ok to the STM32F3 Discovery to confirm it received the data package Since there was only one data package re quested the next message we get from the STM32F3 is a data finished message The program now knows every data that was requested has been delivered and it can wait for new incoming messages The last thing that needs to be looked at is the output of the base station This output can be found in the box below Listing 8 3 output base station pro
31. A Protocols sss savannes TE SE A de 4 4 1 TCP IP Network Protocol 4 5 Conclusion 0 0 ee ee ee ke eee Application Protocol 5 1 Command Package 0 a 5 2 Data Package eee eee eee SO aha TEN TETE Reen DO VD eo eG 5 6 Use Casesl eee 5 6 1 Error Free Communication aa RA dd 5 6 3 Slave to Master Wrong Message 5 6 4 Slave to Master Error Message 5 6 5 Master to Slave Wrong Data Package Messagel paa aa rra ada RO TEEN 6 2 General Architecture 2 a a a 002 ee eee DO DM aa kee REE ae eR ee 6 4 Global Variables 0 0 0 0 00 00000004 ha AREN areas na Cee ue enee asda hee ee nee ees 6 6 1 Base Station Connection Initialization oo sand Dad od owen ess 6 7 Sending to the SIM32F3 Discoveryl 6 8 Receiving from the STM32F3 Discovery 6 9 Receiving from the Base Station 004 6 10 Sending to the Base Station 0 Gl Control Tirado rene eR ee e SA 6 12 Default Setup 2 2 a a 6 13 Complementary Classesl o 6 13 1 Class Command 6 13 2 Class Datal 2 008 ee eee ete ee 6 13 3 Queues reos ess reso dra 6 13 4 Starting Threads 6 13 5 startControl EA AA 6 13 7 startBase
32. Apple Inc version of the X server a component of the X Window System for Mac OS X 23 32 CHAPTER 4 PROJECT DEVELOPMENT TOOLS Last login Fri Mar 21 13 48 41 on ttysdda Machsok Pro van Lauvrens Allarti laurengallart 22h X 248102 166 1 10 p1192 1680 1 10 35 password Linux raspberrypi 3 18 25 622 PREEMPT Fri Jan 3 18 41 88 GMT 2614 armwbl The progress included with the Debian CHU Linus systeem are free software the exact distribution teres for cach progres are described in the individual files in fusr szhare doc s copyright Debian GNU Linux comes with ABSOLUTELY MO WARRANTE to the extent per t by appl E Liter Last login Wed Jan B 04 16 31 2014 from 192 168 1 1 pberrypi se33 ian me ixpolkitr2426 CRITICAL me polkit agent listener register with options assertion P LKIT IS SUBJECT subject failed ispolkit 2426 GLib G0bject CAITICAL ee q_object_unref assertion G IS OAJECT fobjecti failed Dpenbox Message A window manager is already running on screen Y Figure 4 3 Setup ssh in terminal 4 3 2 SSH SSH is a TCP IP protocol that stands for Secure Shell SSH makes it possible to login on another computer in a save way because it is encrypted it is almost impossible to figure out passwords and other information SSH uses public key cryptography to authenticate the remote computer and allow it to authenticate the user if necessary 24 SSH is used to control the Raspberry Pi from another com
33. But generally the method that is used is about the same The Raspberry Pi will be controlled through SSH to get the terminal environment In the software section this topic will be discussed further There was also a program called X11 used to display the graphical user interface on the computer More information about this application can be found in the project development tools 18 CHAPTER 3 AVAILABLE EQUIPMENT Table 3 1 Specification of the Raspberry Pi On Board Chip Broadcom BCM2835 CPU GPU Broadcom BCM2835 CPU GPU DSP SDRAM and single USB DSP SDRAM and single USB port port 700 MHz ARM11 6J7F S core 700 MHz ARM11 6J F S core dota 11 family ARMv6 instruction dem 11 family ARMv instruction sel sel Broadcom VideoCore IV 250 Broadcom VideoCore IV 250 MHz MHz OpenGL ES 2 0 24 GFLOPS OpenGL ES 2 0 24 GFLOPS MPEG 2 and VC 1 1080p30 MPEG 2 and VC 1 1080p30 h 264 MPEG 4 AVC high profile h 264 MPEG 4 AVC high profile decoder and encode decoder and encode Video Input A CSI input connector allows for A CSI input connector allows for the connection of a RPF designed the connection of a RPF designed camera module camera module Video Output Composite RCA PAL and NTSC Composite RCA PAL and NTSC HDMI rev 1 3 amp 1 4 raw LCD HDMI rev 1 3 amp 1 4 raw LCD Panels via DSI Panels via DSI 14 HDMI resolutions from 640x350 14 HDMI resolutions from 640x350 to 1920 1200 plus various PAL and to 192
34. IRECTION 41 WATER DEPTH 45 WATER CONDUCTIVITY 49 WATER TEMPERATURE 62 COMBINATION 67 STOP O quit program 8 3 CONCLUSION 31 the command you chose is WIND SPEED Do you want data from 1 one date 2 between two dates give the date hhmmssssDDMMYYYY 1200000024052014 the command in Hexadecimal numbers is 2431CE0112000000240520142Aa3d33aa0 start analyzing string datel 1200000024052014 command is valid message has been send to the raspberry pi we got a message ok choose one of the following commands and give in 10 MODE ON 14 MODE OFF 23 COORDINATES 31 WIND SPEED 36 WIND DIRECTION 41 WATER DEPTH 45 WATER CONDUCTIVITY 49 WATER TEMPERATURE 62 COMBINATION 67 STOP 0 quit program We received an error from the raspberry pi A start analyzing string command is valid error ID 80 error message 24807F002A9B2C2E59 0 8 3 Conclusion the number 95 There can be concluded that the different programs and threads work well to gether and the different situations in this section represent what the buoy can and can t do Chapter 9 Conclusions 9 1 Achievements After four months of work the main objectives have been achieved The master control unit handles the communication with a base station and with the slave control unit The program is able to manage different incoming messages with different priority levels at the same time
35. IST OF TABLES 6 22 Info makeChecksum function a EE 6 23 Info putInRightQueue function aa a a a a a 78 6 24 Info interruptedQueueHigherPriority function 78 6 25 Info main function 0 0 8 ee ee kk ke 78 Glossary Abbreviation ARM ASCII CDOM CPU CRC32 CSI CSMA CTD DDR DDR RAM DSI DSP e g EO etc FDMA FIFO FOM FPGA PTU GPIO GPRS GPS GPU GSM GUI HDMI ID IEEE IP Description Acorn RISC Machine semiconductor company American Standard Code for Information Inter change Coulored Dissolved Organic Matter Central Processing Unit 32 bit Cyclic Redundancy Check Camera Interface Carrier Sense Multiple Access Conductivity Temperature and Depth Double Data Rate Random Access Memory Display Serial Interface Digital Signal Processor Exempli gratia End Of Header Et cetera Frequency Division Multiple Access First In First Out Figure Of Merit Field Programmable Gate Array Formazin Turbidity Unit General Purpose Input Output General Packet Radio Service Global Positioning System Graphics Processing Unit Global System for Mobile Communications Graphical User Interface High Definition Multimedia Interface Identity Institute of Electrical and Electronics Engineers Internet Protocol Abbreviation ISEP ISP ISUS JTU Kaho KU Leuven LCD LNA LSA MMC MPEG NMEA NTSC NTU OPC ORBCOMM PAL PC RCA RENESAS RF RPF RS
36. Instituto Superior de Engenharia do Porto Departamento de Engenharia Electrot cnica Rua Dr Ant nio Bernardino de Almeida 431 P 4200 072 Porto Environmental Regatta Buoy Telemetry and Configuration Erasmus Project Internship Thesis MSc in Electrical Engineering and Computers Laurens Allart Supervisors Mrs Benedita Malheiro Mr Paulo Ferreira Mr Manuel Silva Mr Pedro Guedes Academic Year 2013 2014 Resumo A monitoriza o ambiental essencial para a tomada de decis es tanto na ci n cia como na ind stria Em particular uma vez que a gua essencial vida e a superf cie da Terra composta principalmente por gua a monitoriza o do clima e dos par metros relacionados com a gua em ecossistemas sens veis tais como oceanos lagoas rios e lagos de extrema import ncia Um dos m todos mais comuns para monitorar a gua implantar boias O presente trabalho est integrado num projeto mais amplo com o objetivo de pro jetar e desenvolver uma boia aut noma para a investiga o cient fica com dois modos de funcionamento i monitoriza o ambiental e ii baliza ativa de re gata Assim a boia tem duas aplica es principais a coleta e armazenamento de dados e a assist ncia a regatas de veleiros aut nomos O projeto arrancou h dois anos com um grupo de quatro estudantes interna cionais Eles projetaram e constru ram a estrutura f sica compraram e montaram o sistema de ancora
37. PI kernel module needed for e g PiFace A6 Audio Force audio out through HDMI or 3 5mm jack A7 Update Update this tool to the latest version lt Select gt lt Back gt Figure 3 7 Raspi config menu 2 Would you like the 55H server enabled or disabled lt Disable gt Figure 3 8 Raspi config menu 3 21 22 CHAPTER 3 AVAILABLE EQUIPMENT ripherals leading to cost reduction at application level and simplifying application design including 14 e Fast and ultra fast comparators lt 30 ns e Op Amp with programmable gain PGA e 12 bit DAC e Ultra fast 12 bit ADCs with five MSPS per channel up to 18 MSPS in interleaved mode e Precise 16 bit sigma delta ADCs 21 channels e Fast 144 MHz motor control timers resolution lt 7 ns e CCM Core Coupled Memory a specific memory architecture for RAM execution of time critical routines accelerating the performance by 43 In Figure 3 9 a picture of the STM32F3 Discovery board can be seen mam disegvery a E H i F E DE E F oo A in cn Figure 3 9 The STM32F3 Discovery board 3 4 Serial Communication For the serial communication two kind of cables were used For testing purposes a serial connection between the Raspberry Pi and the computer was needed This 3 4 SERIAL COMMUNICATION 23 Figure 3 10 USB to USB cable Cr dl C 1 n Figure 3 11 Crossed cable layout 4 was done by a male USB to male USB crossed cable
38. PPROTO IP socket IP ADD MEMBERSHIP mreg return 1 except print error in making the broadcast connection we will try again in 5 seconds time sleep 5 return 0 The code starts again with the creation of a new socket This socket is again the same as the socket in the Raspberry Pi for the multicast messages The two parameters that are given along with the socket socket function are socket AF INET and socket SOCK DGRAL The socket has to bind to the server address as well now This server address is again declared in the defaultsetup py file There must be a side note that says that this server address is empty for multicast messages The next thing that is done is the adding of the socket to the multicast group on all interfaces If this all terminates without errors this function sends a one back to the main thread 7 3 SENDING TO THE RASPBERRY PI 83 If not the program will sleep for 5 s and it will return a zero message 1 3 Sending to the Raspberry Pi In the next three sections of the report the general approach of the three main threads of the base station program will be examined more There is one thread that is responsible for sending commands to the Raspberry Pi and along with that waiting for an acknowledgment Another thread will handle the point to point receiving where messages data or errors will be handled properly And the last thread will take care of the receiving multicast messages In this first section
39. RS 25 Figure 3 13 CTD sensor A picture of the CTD used in the LSA laboratory can be seen in Figure 3 5 1 1 Conductivity The conductivity of an electrolyte solution is a measure of its ability to con duct electricity This is done by applying an alternating current to the outer pair of some electrodes The potential between the inner pair is then measured Conductivity could in principle be determined using the distance between the electrodes and their surface area using the Ohm s law but generally for accuracy a calibration is employed using electrolytes of well known conductivity Table 3 2 shows the conductivity of common solutions 16 Table 3 2 Conductivity of common solutions Conductivity 0 055 pSS em 50 Sem 63 mS om 3 5 1 2 Temperature A PT100 is used to measure the temperature This is a Resistance Temperature Detector RTD The PT100 has a resistance of 100 2 at 0 C The material has a predictable change in resistance as the temperature changes it is this predictable change that is used to determine temperature They have a higher accuracy and repeatability than thermocouples There are two sorts e Wire wound elements consist of a length of fine Platinum wire coiled 26 CHAPTER 3 AVAILABLE EQUIPMENT around a ceramic or glass core The ceramic or glass core can make them fragile and susceptible to vibration so they are normally protected inside a probe sheath for practical use 17
40. SBAS option for example WAAS and EGNOS When a sufficient number of satellites are tracked with valid measurements the SUPERSTAR II produces a 3 D posi tion and velocity output with an associated Figure of Merit FOM 7 3 6 Conclusion In this section the different hardware module that were in our disposal were discussed The master and slave boards were presented the Raspberry Pi and 28 CHAPTER 3 AVAILABLE EQUIPMENT the STM32F3 Discovery and the different sensors that are in our disposal the CTD sensor the anemometer and the GNSS The characteristics of the existing hull available at the LSA laboratory were discussed and with which tools the serial connection is achieved Chapter 4 Project Development Tools In this section the different software development tools that were used will be explained There will be demonstrated which operating systems that were used programs to test the serial connection used programming languages and methods to connect with the Raspberry Pi 4 1 Operating Systems 4 1 1 Raspbian The operating system running on our Raspberry Pi is Raspbian Raspbian is a free operating system based on Debian optimized for the Raspberry Pi hardware An operating system is the set of basic programs and utilities that make the Raspberry Pi run Raspbian is the recommended operating system for the Raspberry Pi and it also has python installed by default Raspbian also allows to be controlled over SHH Th
41. StationReceiving 6 13 8 startBaseStationSending 111 39 39 36 37 37 40 40 41 42 42 42 45 45 48 48 48 iv CONTENTS 6213 9 Thi IVIG2E 8 4 srs errana nd aa SG ew amp 74 6 13 10 starts TM32F3Sending 008 74 6 13 11 starts TMS2F3Receiving ooo a 75 ao aso as 75 O ada ao 75 O Lo l4dataHandling lt s s s s sa s sosa ee See ness Eww 75 6 13 15 commandHandlingl 0 76 ordered asa en 76 6 13 17makeCommand 0 0000 eee ee 76 eee Gea eed teeetauae ee a ae g 76 6 13 19 onescompl eee re DAS 20 0WOSCOMD 2 vine be Saw pri EEE EE aa th A pes ee 77 6 13 22 putInRightQueue a a a a 78 6 13 23 interruptedQueueHigherPriority 78 a A eenen 78 6 14 Simulation of the STM32F3 Discoveryl 78 caso ne 79 81 E III 81 1 2 Multicast Initialization eee 82 O ee ee ee 83 7 4 Receiving from the Raspberry Pi 83 7 5 Receiving Multicast Messages 2 0084 86 7 6 Conclusion 0 eee ee ek kk kk ee 87 8 Results 89 8 1 Introduction 2 0 0 eee ek kk ee 89 8 2 Use Cases 90 8 2 1 Error Free Communication 8 90 8 2 2 Master to Slave Broken Communication 93 8 3 Conclusion ee 95 97 9 1 Achievements 0 0 0 0 ce ee ee ee ee ee 97 9 2 Future Developments
42. TM32F3 Discovery On the slave side of our project the previous student who worked on the project chose the STM32F3 Discovery board to act as a tool that collects and saves data onto a SD card The STM32 F3 series combines a 32 bit ARM Cortex M4 core DSP FPU running at 72 MHz with a high number of integrated analogue pe 20 CHAPTER 3 AVAILABLE EQUIPMENT Figure 3 4 LED indicating the network activity Last login Wed Jun 4 15 59 53 on ttys001 MacBook Pro van Laurens Allart laurensallart ssh X pig192 168 1 10 pi 192 168 1 10 s password Linux raspberrypi 3 10 25 622 PREEMPT Fri Jan 3 18 41 00 GMT 2014 armv6l The programs included with the Debian GNU Linux system are free software the exact distribution terms for each program are described in the individual files in usr share doc copyright Debian GNU Linux comes with ABSOLUTELY NO WARRANTY to the extent permitted by applicable law Last login Thu Apr 3 00 19 22 2014 from 192 168 1 12 pigraspberrypi ifconfig etho Link encap Ethernet HWaddr b8 27 eb 8e 08 60 inet addr 192 168 1 10 Bcast 192 168 1 255 Mask 255 255 255 0 UP BROADCAST RUNNING MULTICAST MTU 1500 Metric 1 RX packets 198 errors 0 dropped 8 overruns 0 frame 0 TX packets 225 errors dropped overruns carrier collisions txqueuelen 1000 RX bytes 16822 16 4 KiB TX bytes 22570 22 0 KiB lo Link encap Local Loopback inet addr 127 0 0 1 Mask 255 0 0 0 UP LOOPBACK RUNNING MTU 65536 Metric 1 RX p
43. The base station sends a message to the Raspberry Pi to ask for data e The Raspberry Pi replies with a message ok back to the base station e The Raspberry Pi sends the command to the STM32F3 Discovery e If the Raspberry Pi doesn t get an answer from the STM32F3 Discovery in a predefined time value called the STMtimeout The Raspberry Pi will send the command again to the STM32F3 Discovery e The program tries this three times If by then the Raspberry Pi didn t get a message back from the STM32F3 Discovery it will stop trying and send a STM32F3 not connected message back to the base station e The Raspberry Pi also get another message ok back from the base station 5 6 3 Slave to Master Wrong Message Figure 5 6Jillustrates the situation when the STM23F3 receives a wrong message for the first time e First the base station sends a command to request data to the master Raspberry Pi e The master Raspberry Pi sends a message ok back to the base station if the command is valid e If there are no other commands that are being handled at that specific mo ment the Raspberry Pi forwards the command to the STM32F3 Discovery 46 CHAPTER 5 APPLICATION PROTOCOL base station Raspberry Pi STM32F3 Send ac Om and to re data Quest Send A co is to re data quest Send ac Om and to re data Quest sM32F3 Not conne Figure 5 5 Broken master slave communication 5 6 USE CASES base station
44. This cable also called Null Modem was needed in order to test the code It was already provided by LSA and can be seen in Figure 3 10 In Figure 3 11 the build up of this kind of cable can be seen The word crossed refers to the crossing of the two connections as can be seen in the Fig ure Because the STM32F3 Discovery doesn t have a normal USB entrance the mini USB entrance was used for the serial communication A normal cable with a USB and a mini USB exit was used This type of cable is widely used in all types of application An example can be seen in Figure 3 12 24 CHAPTER 3 AVAILABLE EQUIPMENT Figure 3 12 USB to mini USB cable 6 3 5 Sensors Sensors are necessary to know different parameters from the environment around the buoy sensor is a converter that measures a physical quantity and converts it into a signal which can be read by an observer or by an today mostly elec tronic instrument 15 There were three main sensors at our disposal A CTD sensor which measures the parameters of the water an anemometer which measures the characteristics of the wind and a GNSS which determines the global position and keeps track of the time These sensors where also chosen by the previous students and they were already available when this project started 3 5 1 CTD This sensor package was developed in LSA The CTD sensor measures three variables e Conductivity e Temperature e Depth 3 5 SENSO
45. ackets 51 errors dropped 0 overruns frame 0 TX packets 51 errors 0 dropped overruns 0 carrier 0 collisions txqueuelen 0 RX bytes 5117 4 9 KiB TX bytes 5117 4 9 KiB pigraspberrypi E Figure 3 5 Ifconfig command 3 3 STM32F3 DISCOVERY Raspberry Pi Software Configuration Tool raspi config Setup Options Expand Filesystem Ensures that all of the SD card storage is available to the OS Change User Password Change password for the default user pi Enable Boot to Desktop Scratch Choose whether to boot into a desktop environment Scratch or the command line Internationalisation Options Set up language and regional settings to match your location Enable Camera Enable this Pi to work with the Raspberry Pi Camera Add to Rastrack Add this Pi to the online Raspberry Pi Map Rastrack Overclock Configure overclocking for your Pi Advanced Options Configure advanced settings About raspi config Information about this configuration tool a 2 3 4 5 6 7 8 9 lt Select gt lt Finish gt Figure 3 6 Raspi config menu 1 Raspberry Pi Software Configuration Tool raspi config Advanced Options Al Overscan You may need to configure overscan if black bars are present on display A2 Hostname Set the visible name for this Pi on a network A3 Memory Split Change the amount of memory made available to the GPU A4 SSH Enable Disable remote command line access to your Pi using SSH A5 SPI Enable Disable automatic loading of S
46. age should be send again The flowchart of this can be found in Figure 6 11 Control Thread The last thread is the control thread This thread deals with the messages the Raspberry Pi got from the base station The control thread determines in which priority queue the messages needs to be in and whether or not a command that has just been send to the STM32F3 Discovery and where The Raspberry Pi is receiving data from should be interrupted for this new command In Figure the flowchart for the control thread can be seen This thread first checks if there are new commands in the incomingQueue This is the queue where the receiving part of the base station communication puts the new commands in The thread checks again if this message is a valid message Next the command is put in the correct priority queue This means we look at the ID of the command and from that ID the priority is determined The priorities of the different ID can be modified in the default setup file The next thing the program checks is the state of the STM32F3 Discovery communication If the state says it is receiving data we check if the priority of the incoming message is smaller than the priority of this busy command If this is the case the control thread calls the function interruptData The flowchart of this method can be found in Figure 6 10 CHAPTER 6 RASPBERRY PI IMPLEMENTATION startBaseStationReceiving No quit the program Yes
47. ageOk wrongData baseStationTimeout STMTimeout busyCommand lastData CHAPTER 6 RASPBERRY PI IMPLEMENTATION Table 6 1 Global variables of the program uses them 1 the TCP connection with the base station is open O there is no connection TCP IP Boolean Boolean Boolean Boolean This is the command that is currently being processed If Command there isn t any this is equal to object the zeroCommand 1 there is a serial connection with the STM32F3 Discovery O there is nog serial connection 1 the program is trying to quit O the program is running of the Discovery Defines the state STM32F3 communication 1 the Raspberry Pi is waiting for a message ok from the base station O the Raspberry Pi waiting 1 isn t if there was a wrongData command received from the base station O There wasn t a wrongData received The number of times there couldn t be made a connection with the base station This has to be smaller than 3 The number of times the program couldn t connect with the STM32F3 Discovery This has to be smaller than 3 This is the a data object of the last data package that was received This is necessary for when the program interrupts the data class baseStation initBaseStation class STM32F3 Discovery initSTM32F3 Discovery startBaseStationReceiving startControl every thread startControl interruptData commandHandling dataHandling sendCom
48. ain characteristics of the hull are e Relatively small e Light weight because it is made of fiberglass e Six bolts need to be unscrewed to open the top e The nuts have been replaced and covered with a layer of glass reinforced plastic e Rubber washers for the bolts to seal the threaded connection e Ethyleen Propyleen Dieen Monomeer EPDM rubber tape 3 mm x 25 mm x 10 000 mm is attached to the hull e A waterproof box is inside the hull to put the electrical components in for extra protection against the water The steel structure was added later and is necessary for the following reasons 15 16 CHAPTER 3 AVAILABLE EQUIPMENT Figure 3 1 Buoy hull 4 e Onto the steel structure the sensors will be attached So there has to be enough space on the steel structure to mount the sensors on e It acts as reinforcement for the hull It must provide some extra strength to the buoy e They also made sure the steel structure is resistant against wind and waves e t makes the buoy taller so it will be more visible from further distances Especially when there is a light source attached to the top the buoy will be much more visible from a larger distance In Figure 3 2la picture of the hull plus the steel structure can be seen 3 2 Raspberry Pi Because the Beaglebone black was not available at LSA we got the Raspberry Pi instead The Raspberry Pi is mini Linux computer that has approximately the same f
49. an be seen init base station a def initBaseStation global s global client global addr global openTCP global quit i 0 while i 0 quit 0 try s socket socket socket AF INET socket SOCK STREAM s bind defaultsetup HOST defaultsetup PORT s settimeout defaultsetup TCP TIMEOUT i l except print n Can t make contact with the base station We will try again in s seconds defaultsetup TIME TO RETRY time sleep defaultsetup TIME TO RETRY 2 for testing purposes if i l i 0 while i 0 amp quit 0 try S listen 1 print Listening for connections client addr s accept print connection with client print client print at adress print addr i 1 openTCP 1 except print the base station doesn t answer In the code the sequential order of setting up a TCP IP connection can be seen The first thing the program tries to do is setting up a socket T his socket is called s and this is a global variable which means that other threads and functions can also use this variable For a normal point to point connection like this one the parameters socket AF_INET and socket SOCK_STREAM are given along with the function socket socket The next thing that is done is binding the socket to our host address and a port The host address is the IP address of the Raspberry Pi because the Raspberry Pi will be the server If these ac tions succeed the timeout for the connection
50. an communicate with To achieve this there is also need for an implementation of the base station In the program of the base station it has to be possible to choose a command that has to be send to the base station The base station has to send proper acknowledgment messages to the Raspberry Pi conform to the protocol In this section there will also be explained how to receive broadcast messages The base station can use this and it can also be implemented in other vehicles that are interested in these messages In the regatta boat races for example this can be implemented in the boats 1 1 TCP IP Connection In this section the initialization of the TCP IP connection between the Raspberry Pi and the base station will be discussed The initialization will be different than on the Raspberry Pi side because the base station acts as the client and not the server The code can be found beneath def initConnection global s s socket socket socket AF INET socket SOCK STREAM Creates a socket s settimeout defaultsetup TCP TIMEOUT print created a socket try s connect defaultsetup HOST defaultsetup PORT Connect to server address print connected return 1 except print didn t manage to get a connection time sleep 5 return 0 81 82 CHAPTER 7 BASE STATION IMPLEMENTATION The first thing that is done is again making a socket This socket has the same parameters as on the Raspberry Pi side namely socke
51. ance Detectors 10 2 3 2 3 Water Velocity 10 2 3 2 4 Water Turbidity 10 23 209 Water Di s usaria ED E A 11 die o ee Gok ak me eo eo 11 2 4 Related Work 2 2 2 ee 0 11 2 4 1 Autonomous Meteorological Buoy 11 2 4 2 Technology Design and Operation of an Autonomous Buoy System in the Western English Channel 11 2 4 3 Implementation of Embedded System for Autonomous Buoy 12 25 COMCIUSI N cross ELLE EEE ST RE E 13 3 Available Equipment 15 3 1 Hull and Steel Structure 2 a 15 3 2 Raspberry Pll www wm 644 64 ARO RE RE de we eS de ES 16 3 2 1 Specifications sis es HGS SS ew oe EE 16 3 2 2 Controlling the Raspberry Pi 17 3 2 3 Setting up the Raspberry Pil aaa aa 18 do OL MS2ES DISCOVERY ss se iwr ss na AM A ad 19 Eeen Aa 22 dO DOMSO S covas coro Oe Gow ERS ss SES AESA 24 DOM Og tee Pak eee eae eee ee ee eae ga 24 3 5 1 1 Conductivity 2 2 2 008 25 3 9 1 2 Temperature o 25 3 5 1 3 Presse amp eoGpbachovee dee hha dws 26 3 0 2 Anemometer oaoa aoa a a 26 AAC AA 26 PN as 27 4 Project Development Tools 29 4 1 Operating Systems a oa a ene 29 411 Raspbian EEE 29 ANA EEE 30 Ree 30 IL ESOO EEE 30 a AE l ASA CA EEE 31 Er 32 EE REDE ee 33 4 3 4 CheckSum and ModeOn Applications 34 CONTENTS 5 A
52. are the biggest reasons there was decided to use this programming language for the project Python is also included with the Raspbian operation system There must also be noted that the 2 7 X version of python was used This is important to know because python 2 X and python 3 X are not compatible with each other In Figure 4 2 the official python logo can be seen 4 3 SOFTWARE 31 Figure 4 2 Python logo 9 4 3 Software 4 3 1 X11 X11 or also referred to as X Window System is a windowing system for bitmap displays common on UNIX like operating systems X11 provides the basic framework for a GUI environment drawing and mov ing windows on the display device and interacting with a mouse and keyboard X does not mandate the user interface individual programs handle this As such the visual styling of X based environments varies greatly different programs may present radically different interfaces Unlike most earlier display protocols X was specifically designed to be used over network connections rather than on an integral or attached display device X features network transparency the machine where an application program the client application runs can differ from the user s local machine the dis play server X s network protocol is based on X command primitives This approach allows both 2D and 3D operations to be fully accelerated on the remote X server 22 The program used is the XQuartz application the
53. artSTM32F3Receiving It changes the state of the Description state machine depending on the current state and the type of command that came in Inputs Command Outputs none 6 13 16 makeData Table 6 17 Info makeData function Description This function makes a Data object out of a hexadecimal string Inputs Hexadecimal string Outputs Data 6 13 17 makeCommand Table 6 18 Info makeCommand function Description This function makes a command object out of a hexadecimal string Inputs Hexadecimal string Outputs Command 6 13 18 interruptData Table 6 19 Info interrupt Data function This function handles when there is need to interrupt a message that is currently Description in progress It sends a stop command to the STM32F3 Discovery and it saves the command that is in progress Inputs none Outputs none 6 13 COMPLEMENTARY CLASSES 77 6 13 19 onescomp Table 6 20 Info onescomp function Description This method does a one s complement operation on a binary string Inputs Binary string Outputs Binary string 6 13 20 twoscomp Table 6 21 Info twoscomp function Description This method does a two s complement operation on a binary string i Inputs Binary string Outputs Binary string 6 13 21 makeChecksum Table 6 22 Info makeChecksum function Description This function makes the CRC32 checksum from a given hexadecimal string
54. atapackage or error send to the base station received a command from the base station Command 249966002aa5caaeb3 received a message ok from the base station This is actually the same as in the previous situation except that this time the Raspberry Pi doesn t send data package to the base station but an error package The other output file is much more interesting to look at It can be found under this line Listing 8 5 output STM32F3 communication Starting STM32F3 communication Starting control thread the serial connection object is equal to Serial lt id 0xb69647b0 open True gt port dev ttyUSBO baudrate 9600 bytesize 8 parity N stopbits 1 timeout 3 xonxoff False rtscts False dsrdtr False 94 CHAPTER 8 RESULTS send default mode message to the STM32F3 can t make contact with the STM32F3 we sended 2410EF090001230000010000002A76611B52 again to the STM32F3 times we tried to reach the SIM32F3 1 can t make contact with the STM32F3 we sended 2410EF090001230000010000002A76611B52 again to the STM32F3 times we tried to reach the STM32F3 2 can t make contact with the STM32F3 we sended 2410EF090001230000010000002A76611B52 again to the STM32F3 times we tried to reach the STM32F3 3 Didn t receive a message back from the STM32F3 Default mode failed got command out of queue6 sending the command text send to the STM32F3 waiting for a resp
55. d A lock is also applied to make sure no other thread will access the variables that are used For connecting to the serial port the library serial needs to be imported A serial connection can be started now by giving in the command ser serial Serial defaultsetup PATH USB DRIVER defaultsetup BAUDRATE timeout defaultsetup SERIAL TIMEOUT Where the ser variable will represent the serial connection object default setup PATH USB DRIVER represents the path on the Raspberry Pi that locates the USB driver This is different for different USB connections There must be noted that every constant is located in the default setup py file and can be mod ified Also the baud rate of the serial connection and the timeout are specified in this command They can also be found in the default setup py file Normally 9600 b s is used as a standard baud rate The timeout is equal to three seconds by default openser is the variable that is one if the serial connection is successfully made and its purpose is to let other threads know the serial connection is established 58 CHAPTER 6 RASPBERRY PI IMPLEMENTATION 6 6 Server Client Connection In this section the establishment of the TCP point to point connection with the base station and the setup of the UDP point to multipoint message multicasting will be discussed 6 6 1 Base Station Connection Initialization In the code beneath the actual implementation in python of the TCP IP connec tion setup c
56. d on the beginning of a new session Now let s start with some situations 89 90 CHAPTER 8 RESULTS 8 2 Use Cases 8 2 1 Error Free Communication This is a very normal situation We start the Raspberry Pi and the base station program When the Raspberry Pi starts up it will check if there is a default mode that needs to start up If there is the Raspberry will send a mode on command to the STM32F3 Discovery From the base station we then send a request for wind speed data on the 24th of may 2014 at 12 o clock 1200000024052014 The Raspberry Pi will now ask these data on the STM32F3 Discovery and when it receives this data it will forward it to the base station First of all let s take a look at the outputs of the Raspberry Pi for the base station communication The output can be seen below Listing 8 1 output base station communication Starting baseStation communication Listening for connections from a base station connection with client lt socket _socketobject object at Oxb69838b8 gt at address 192 168 1 12 56685 received a command from the base station Command 2431ce0112000000240520142aa3d33aa0 message ok send back to the base station command in queue6 datapackage or error send to the base station received a command from the base station Command 249966002 aa5caaeb3 received a message ok from the base station The output starts with the initialization of the connect
57. date of the last datapackage we received change the beginning date from the busy command in that data and time put the command in the interruptedQueue return Figure 6 10 Flowchart for the interrupt data function 6 13 COMPLEMENTARY CLASSES 71 Table 6 2 Default setup parameters Path ta the PATH USB DRIVER driver of the dew ttyvACMO USB port Baudrate of BAUDRATE the serial 9600 bis connection Timeout of SERIAL TIMEOUT the serial connection IP adres of the 197 168 1 10 Raspberry Pi Part tor the connection PORT with the 4446 base station Timeout af the TCP TIMEOUT connection with the base station Time that the Raspberry Pi TIME TO RETRY waits when 10s he can t find a connection Number ot data bytes in a data packet Array of ID that represent a ror 08 data package Array of ID that COMMANDID represent a 10 14 23 31 36 417 45 49 62 67 99 80 82 84 86 88 90 command message Array of ID that represent an error Array of ID that SENSORID represent a 23 31 36 41 457 49 sensor function Each of these parameters je kaper See in the defaultsetup py file ID that have a certain priority Mode that starts by default on start up DATASIZE ERRORID 80 82 84 66 68 DEFAULTMODE 2410EFO9000 12300000 1000000247661 1852 6 13 Complementary Classes 6 13 1 Class Command The class Command is a class that
58. e important differences are e The marine environment is an aggressive one which requires greater levels of device protection e Allowance must be made for movement of buoys caused by tides waves vessels etc e Energy consumption is high since it is generally necessary to cover large distances while communications signals are attenuated due to the fact that the sea is an environment in constant motion 6 CHAPTER 2 STATE OF THE ART e The price of the instrumentation is significantly higher than in the case of a land sited wireless sensor networks e There are added problems in deployment of and access to motes and the need for flotation and mooring devices In Figure a general overview of a sensor node can be seen In the center there is the CPU which is a microprocessor which processes all the data from the sensors and takes care of the communication between the base station or with other buoys The rest of the system includes a module for RF transmis sions a power supply regulation and management system a set of interfaces for accessing the sensors a module for amplification conversion analogue to digital and multiplexing of the data read from the sensors surface and underwater a FLASH type permanent read write memory and a clock to act as a timer and scientific instruments e g improved meteorological packages acoustic recording packages biological samplers etc Part of most buoys is above the surface of
59. e same thing counts when an error was received but there is a mistake in the command package the program stays in the same state but immediately a wrong command message is send back 6 4 Global Variables In order to make the flowcharts which will be discussed later on more clear some variables that are used in the program will be explained here There must be noted that these variables are global variables This means that these variables can be read and modified by all the threads They represent the communication between the different threads All the global variables plus some information can be found in Table In this Table you can also find in which functions these variables will be used in the program 6 4 GLOBAL VARIABLES Send Message ok back state O waiting for a message from the base station state 2 Command that doesn t need data in Queue state 1 Command that needs data in Queue state 7 Command send to the STM32F3 state 3 Command send to the STM32F3 state 4 message ok received from STM32F3 state 5 data package received from the STM32F3 message ok send to STM32F3 state 6 data finished command received from the STM32F3 puewwo dos pue ananb pejdnusjui ul puewwos md ananbeyep ul Jose nd state 9 error received Figure 6 3 State machine of the STM32F3 Discovery communication dO 56 stateSTM waitingMess
60. eatures as the Beaglebone Black The Raspberry Pi has a Broadcom BCM2835 system on a chip SoC which includes an ARM1176JZF S 700 MHz processor VideoCore IV GPU and is shipped with 512 MB of RAM It does not include a built in hard disk or solid state drive but uses an SD card for booting and persistent storage There are 2 USB 2 0 ports and HDMI rev 1 3 and 1 4 and RCA are included for video output An audio jack Ethernet port and a microUSB power port are also included on the board 3 2 1 Specifications in Table 3 1 the specifications of the two Raspberry Pi models can be seen The one that was in our disposal is model B These specifications are definitely good enough for the application we intend to make The Raspberry Pi also has a lot 3 2 RASPBERRY PI 17 Figure 3 2 LSA buoy of in and outputs The most important one for us is the USB connection and the Ethernet adapter for testing purposes When the user wants to connect a mouse and a keyboard to the Raspberry Pi he will also need a USB hub because the two USB ports are already used for the Wi Fi network adapter and for the connection between the Raspberry Pi and the STM32F3 Discovery 3 2 2 Controlling the Raspberry Pi Because there was no external monitor available all the time there was decided to control the Raspberry Pi from a personal laptop The computer that was used is a Macintosh so the approach is a little bit different than on Windows or Linux computers
61. eivers are incorporated thus providing am plification to improve both output power and LNA Low Noise Amplification 2 3 SENSORS 7 X antenna mast antenna surface sensors van Harvesting system TA eg solar panel Sensor Inariacas AD Converters Amplifiers Multiple sears busy protection case platform Sensor Interfaces mooring line underwater i buoy weight diving unit sensors sensor strings anchor Figure 2 1 General architecture of an autonomous buoy Another option where such devices are insufficient to cover the distance is to include a GSM GPRS module Table 2 1 displays existing communication tech nologies 2 2 3 Sensors There are many types of sensors for monitoring oceanographic parameters The sensors you need depend on the project We will discuss the most important ones here and we will divide the sensors in two groups the ones that must be mounted above the surface of the water and the ones that must be in the water in Figure and Figure you can see a picture of the CTD sensor we use and an example of the anemometer CHAPTER 2 STATE OF THE ART Table 2 1 Communication technologies Technology Description Throughput B02 lla 802 11b g n Bluetooth IEEE 802 15 4 System of wireless data transmission over computational networks Standard for data transmission using radio waves Industrial specification for WPAN which enables voice and
62. ensagens com informa o de posi o e condi es de vento e gua no modo de regata Enquanto que a comunica o entre a unidade de controlo mestre e a esta o base e a unidade de controlo mestre e os barcos sem fios a unidade de controlo mestre e a unidade de controlo escrava comunicam atrav s de uma liga o s rie A boia tem atualmente duas limita es i a carga m xima de 40 kg e 11 apenas pode ser utilizada em rios ou pr ximo da costa dada limita o de dist ncia imposta pela t cnica de comunica o sem fios escolhida Abstract Environmental monitoring is essential for decision making both in science and industry In particular since water is essential to life and the Earth s surface consists mostly of water monitoring the weather and water related parameters in sensitive ecosystems such as oceans lagoons rivers and lakes is of the greatest importance One of the most commons methods to monitor water is to deploy buoys The current work is part of a larger project with the aim to design and develop a dual mode autonomous buoy for scientific research i environmental monitor ing and ii regatta beacon As a result the buoy has two major applications collection and storage of data and assistance in autonomous sailing boat regattas The project started two years ago with a group of four international students They designed and built the physical structure and selected and assembled the anch
63. ese are the biggest reasons there was chosen to stick with this operating O Raspbian Figure 4 1 Raspbian Logo system 29 30 CHAPTER 4 PROJECT DEVELOPMENT TOOLS 4 1 2 ChibiOS ChibiOS is the operating system that is used on the STM32F3 Discovery board This was also decided by the previous students ChibiOS is a complete portable fast compact open source Real time operating system RTOS The advantage of ChibiOS is that it provides e Start up and the board initialization e Integration of other open source projects e Support for common device drivers A lot of information about ChibiOS will not be displayed here because of the fact that it has more to do with the data logging part of the project ChibiOS is not used in the communication part For more information you can go to the ChibiOS website or on the report on data logging 20 4 2 Programming Languages 4 2 1 Python Python is a widely used general purpose high level programming object oriented language Its design philosophy emphasizes code readability and its syntax allows programmers to express concepts in fewer lines of code than would be possible in languages such as C The language provides constructs intended to enable clear programs on both a small and large scale Python is often used as a scripting language but is also used in a wide range of non scripting contexts 21 The simplicity cross platform support and the big user community
64. essage ok message from the base station Another important difference is that the receiving part also sends messages back to the base station The sending part is only responsible for the sending of packages in the data queue The data queue is the queue where all the data packages and errors the program gets from the STM32F3 Discovery are collected All the other control messages that are send to the base station are send by the receiving thread When looking at the receiving thread flowchart seen in Figure 6 7 the thread checks first if there is something coming in from the base station If this is the case the programs checks if this message is equal to quit If it is the quit variable will be equal to one The next thing is making a command object out of the in coming string If the command object is equal to the zeroCommand This means something went wrong in making the command object a wrong command is send back If the return message is a message ok the receiving thread checks if the variable waitingMessageOk is equal to 1 This means that the sending thread is waiting for a message ok If a message ok was received we make this variable zero again If this is not the case the thread checks if it is a wrong data message If this is the case the variable wrongData is changed to one This way the send thread will now it has to send the data package again If the incoming package is not a message ok not quit not a wr
65. gem da boia e escolherem a maioria dos componentes eletr ni cos para o sistema geral de controlo e medi o Este ano durante o primeiro semestre dois estudantes belgas Jeroen Vervenne e Hendrick Verschelde tra balharam nos subsistemas de recolha e armazenamento de dados unidade de controlo escrava e de telemetria e configura o unidade de controlo mestre as sim como definiram o protocolo de comunica o da aplica o O trabalho desta tese continua o desenvolvimento do subsistema de telemetria e configura o Este subsistema respons vel pela configura o do modo de funcionamento e dos sen sores assim como pela comunica o com a esta o de base controlo ambiental barcos baliza ativa de regata e com o subsistema de recolha e armazenamento de dados O desenvolvimento do subsistema de recolha e armazenamento de da dos que coleta e armazena num cart o SD os dados dos sensores selecionados prossegue com outro estudante belga Mathias van Flieberge 111 O objetivo desta tese por um lado implementar o subsistema de teleme tria e de configura o na unidade de controle mestre e por outro lado refinar e implementar conjuntamente com Mathias van Flieberge o protocolo de n vel de aplica o projetado Em particular a unidade de controlo mestre deve processar e atribuir prioridades s mensagens recebidas da esta o base solicitar dados unidade de controlo escrava e difundir m
66. gram MacBook Pro van Laurens Allart versie 17 laurensallart python baseStation_v10 py created a socket Starting Sending thread Starting Receiving thread Starting Receiving Broadcast messages choose one of the following commands and give in the number 92 CHAPTER 8 RESULTS 10 MODE ON 14 MODE OFF 23 COORDINATES 31 WIND SPEED 36 WIND DIRECTION 41 WATER DEPTH 45 WATER CONDUCTIVITY 49 WATER TEMPERATURE 62 COMBINATION 67 STOP O quit program 31 the command you chose is WIND SPEED Do you want data from 1 one date 2 between two dates give the date hhmmssssDDMMYYYY 1200000024052014 the command in Hexadecimal numbers is 2431CE0112000000240520142Aa3d33aa0 start analyzing string command is valid message has been send to the raspberry pi we got a message ok choose one of the following commands and give in the number 10 MODE ON 14 MODE OFF 23 COORDINATES 31 WIND SPEED 36 WIND DIRECTION 41 WATER DEPTH 45 WATER CONDUCTIVITY 49 WATER TEMPERATURE 62 COMBINATION 67 STOP 0 quit program we received data start analyzing data time 12 00 00 00 date 24 05 2014 ID 0 31 data 0 53656e736f723a20576953702c204d4553203100 send message ok back After the initialization the base station program will display the different possibilities to send to the Raspberry Pi To choose a wind speed request you have to give in the number 31 as can be seen in the
67. he cool Term setup 4 3 4 CheckSum and ModeOn Applications In order to make testing easier we made two little python programs that would make testing more easy The first one is makeChecksum makeChecksum is a little program that will ask for a hexadecimal string and it will display the CRC32 checksum of that string This program can also be found in the appendix An example of this program can be found in the output window below MacBook Pro van Laurens Allart versie 17 laurensallart python makeChecksum py Give here the string of hexadecimal symbols LAZB3C4D5E6F The CRC32 checksum of this string is equal to 9El4CBD2 Another little python program that was made by me is makeModeOn This program was also created to make testing more easy but it can also be used to add a default mode in the defaultsetup file It is used to make a mode on command package out of some parameters you give in An example is given in the output window below 4 4 PROTOCOLS 35 MacBook Pro van Laurens Allart versie 17 laurensallart python makeModeOn py Give here the ID number of the Mode this can be anything you like but maximum 2 Hex characters 01 How many sensor functions do you want to use im Choose function number O 23 COORDIMATES idl WIND SPEED 36 WIND DIRECTION Al WATER DEPTH 45 WATER CONDUCTIVITY 43 WATER TEMPERATURE 23 Choose function number 1 23 COORDINATES 31 WIND SPEED 36
68. ieven institution the KU Leuven and the Instituto Superior de Engenharia do Porto These three institutions made it possible to fulfil my thesis in well organized encouraging atmosphere I would especially like to thank the Laborat rio de Sistemas Au ton mos LSA of the Instituto Superior de Engenharia do Porto ISEP for the project I could work on I really liked working in their environment and I had a great time working there A special thank should be offered to Mrs Benedita Malheiro Mr Paulo Fer reira Mr Manuel Silva and Mr Pedro Guedes for holding the weekly meetings giving me tons of advice and helping me a lot in the progress of making my project Without these people and their knowledge it would have been much harder to make this project into a success They always answered immediately on my questions and the weekly meeting were a good drive to start fresh when ever I was stuck I especially want to mention Mrs Benedita Malheiro for her involvement and enthusiasm in the project She always made me feel comfortable here without letting me lose my focus on the project Last of all I would like to thank her for the help she gave me with making the wiki and the Latex report I also want to show my appreciation for Mr Paulo Ferreira for helping me out with all kind of technical questions about python networks or serial communica tion He always had a good answer ready for me I want to thank him also for learning me more
69. if there were no problems the two are now connected The light emitting 3 3 STM32F3 DISCOVERY 19 h 1 iio a Y O P2 aanhad leef mn en i j RENO Tae i na RD El t q ls AA ol Ru B88 rs ca Roa Cis Fa A q Figure 3 3 How to connect the Raspberry Pi diodes that are responsible for the Internet can be seen in Figure 3 4 Before the controlling of the Raspberry Pi can start the user needs to know the IP address of the Raspberry Pi For this part you need an external monitor and keyboard In the terminal of the Raspberry Pi you type the command ipconfig for more information about the network When the IP address is known the user can start In this case the IP address is 192 168 1 10 An example of this can be seen in Figure The last thing that needs to be done is make sure the SSH option is enabled in the Raspberry Pi When you are in the command line of the raspberry type in the command raspi config This will open up a screen with lots of features of the Raspberry Pi Go to Advanced Options and select it You will get another screen were you will have to select SSH Now you can choose enable or disable We want to choose the enable option of course These steps can be seen in Figure 83 Band Bl The next thing that is done is start the terminal utility on the laptop and type the command ssh X pi 192 168 1 10 Further steps will be explained in the SSH topic of this report 3 3 S
70. ime and date of the data package After the time and the date data of different sensors can be added The EOH is again the sign To secure the message a CRC32 checksum is added in the end The different data ID values that are added are the same as the ID numbers of the similar command packages For example when you want to add the wind direction in a data package the ID number you add to the data package is 36 5 3 Priorities When different commands come in at the same time there need to be some pri orities With priorities the processor knows which command he should handle first All the commands used by the protocol are divided into similar groups and given all a certain priority They can be seen in Table 5 3 The stop command has the highest priority and will always be handled first The second most impor 5 4 CRC32 CHECKSUM 41 Table 5 3 Priorities of the different messages Commands Stop command 67 op message 1 2 SDC not connected CNSS not connected Error 8 6 Wrongeommand B Wrong data MEN BT Combination er ooo Wind 3 6 Wind direction 4 gt Combination 4 Water conductivity Water temperature tant command is the error command followed by the change modes the mode on or the mode off command The lowest priorities are the different sensor commands where the combination of sensors has the highest priority followed by the GPS Wind sensor and CTD respectively
71. implementation and the methods that were used to do this 1 4 1 General Objective The general objective of the autonomous buoy is to monitor his environment This should be done by collecting data from the sensors storing this data and sending 1t to a base station or when it is in a broadcast mode to anyone who is interested One of the objectives is that the buoy should have two main operating modes which can run simultaneously an environmental mode and a regatta mode 4 CHAPTER 1 INTRODUCTION 1 4 2 Environmental Mode This mode is a mode that is used to collect data over larger periods of time to monitor the environment When the base station arrives in range of the Wi Fi module of the buoy specific data can be requested from the buoy The buoy only sends information to one point the base station 1 4 3 Regatta Mode The regatta mode is a mode that was created so the buoy can assist an au tonomous sailing boat that will be constructed at LSA in the future The pur pose of this mode is to broadcast necessary information for everybody that is interested The time intervals between two measurements are smaller and the information can only be gathered at the moment it is being send The boats can t request any information about the past Once the data is send the boats have to capture it or otherwise it is lost 1 4 4 Objectives Regarding The Master Module The master module should be able to send and receive messages
72. io of the partial pressure of water vapour in an air water mixture to the saturated vapour pressure of water at a prescribed temper ature The relative humidity of air depends on temperature and the pressure of the system of interest It is displayed in RH 2 3 1 6 Solar Radiation These sensors measure the amount of electromagnetic radiation produced by the sun that is perceived by the buoy It measures the amount of energy on a certain surface and is displayed in W m 2 3 2 Oceanographic Sensors 2 3 2 1 CTD The CTD is a sensor that measures three important state values of the water conductivity temperature and depth It is also a sensor we use in our project 2 3 2 2 Chemical Substance Detectors There are a lot of sensors available that measure one type of substance For exam ple you have devices that detect oxygen mg L CO2 ppm chlorophyll ug L chloride mg L Rhodamine ug L Hydrocarbons ppm Ammonium ammonia Img I N or nitrate mg L 2 3 2 3 Water Velocity This sensor measures the velocity of the water near to the buoy The water speed is given in units of m s 2 3 2 4 Water Turbidity Turbidity is the cloudiness or haziness of a fluid caused by individual particles total suspended or dissolved solids that are generally invisible to the naked eye similar to smoke in air The measurement of turbidity is a key test of water quality There are different units to express the turbidity of water e FTU F
73. ion After this the Raspberry Pi received a command from the base station followed by the hex adecimal code of the command The Raspberry Pi sends a message ok back to base station and puts the message in queue6 according to the message priority Once data is obtained by the Raspberry Pi from the STM32F3 Discovery and put in the dataQueue The Raspberry Pi can send it to the base station After the sending of the data package the thread will wait for a message ok command from the base station Since we only asked one data package this is the end of our first situation Now let s look to the output of the STM32F3 communication threads for this situation The output can be found below Listing 8 2 output STM32F3 communication Starting STM32F3 communication Starting control thread 8 2 USE CASES 91 the serial connection object is equal to Serial lt id 0xb6989790 open True gt port dev ttyACMO baudrate 9600 bytesize 8 parity N stopbits 1 timeout 3 xonxoff False rtscts False dsrdtr False send default mode message to the STM32F3 received a message from the STM32F3 249966002 aa5caaeb3 message ok received from the SIM32F3 got command out of queue6 sending the command text send to the STM32F3 waiting for a response received a message from the STM32F3 249966002 aa5caaeb3 message ok received from the STM32F3 received data from the STM32F3 2407120000002
74. it would make this report too extensive The code is also provided and heavily commented if something should be not that clear of how we did it in actual python code In the next chapter there will be some test results of the final program Chapter 8 Results 8 1 Introduction The different results of our program will be explained here The outputs of the different threats will tell more about the flow of the program Because there are multiple threads running in the same application on the Raspberry Pi the output in the terminal window can become a little bit messy All the threads are print ing information in the command window at the same time That is why there was decided to make a log file of the threads that deals with the communica tion between the Raspberry Pi and the STM32F3 Discovery and another log file for the threads that deal with the communication between the Raspberry Pi and the base station The output of the control thread is also added to the first log file These log files are cleared every time the program starts up again This means that in these log files you can only find information about the last session In the base station there are also two files One that saves the data we re quested and one that collects the broadcast data We can also follow the data on the output screen of the application but for larger data packages it is useful to put them into a file The broadcast data file will also be cleare
75. mandWithData sendCommandWithoutData startSTM32F3 DiscoveryReceiving startSTM32F3 DiscoverySending startBaseStationSending startBaseStationReceiving startBaseStationSending startBaseStationReceiving startBaseStationSending startBaseStationReceiving sendCommandWithoutData sendCommandWithData startSTM32F3 DiscoveryReceiving SendCommandWithoutData sendCommandWithData startSTM32F3 DiscoverySending startContral interruptData make Data 6 5 SERIAL CONNECTION 57 6 5 Serial Connection For the initialization we are going to look at the python code that is used to initialize the serial connection import serial init STM32F3 def initSTM32F3 initialise the STM32F3 communication global ser the serial connection is called ser it can be used in multiple methods so we make it global global quit global openSer openSer 0 trys lock acquire ser serial Serial defaultsetup PATH USB DRIVER defaultsetup BAUDRATE timeout defaultsetup SERIAL TIMEOUT openSer 1 lock release print ser return 1 except print n The STM32F3 is not connected make sure the USB cable is connected properly We will try again in 10 seconds lock release time sleep 10 return 0 The initialization is situated inside a loop in the main thread to make sure the initialization will only stop if there is an actual connection If the connection succeeds a one value is returned if the connection fails a zero is returne
76. n function for the receiving thread from the STM32F3 Discovery It reads messages from the STM32F3 Discovery and checks if it is a data message or a command message If it is a data message he calls the dataHandling function to change the state accordingly other wise it will call the commandHandling function Inputs none o Outputs none 6 13 12 sendCommandWithData Description sequential order of the protocol Table 6 13 Info sendCommandWithData function This function is responsible for sending messages that require data from the STM32F3 Discovery It is responsible for maintaining the states and to keep the Inputs Command E Outputs none 6 13 13 sendCommandWithoutData Table 6 14 Info sendCommand WithoutData function Description This funtion does approximately the same as the sendCommandWithData but the States are different because these commands don t require data from the STM32F3 Discovery Inputs Command c Outputs none 6 13 14 dataHandling Description Table 6 15 Info dataHandling function This function is called by the startSTM32F3Receiving It changes the state of the state machine depending on the current state and the type of dataMessage that came in Inputs Data Outputs none 76 CHAPTER 6 RASPBERRY PI IMPLEMENTATION 6 13 15 commandHandling Table 6 16 Info commandHandling function This function is called by the st
77. nd direction If the wind turns so will the vane change position This change changes the value of the potentiometer But this wont be sufficient to determine the wind direction The buoy can turn and because the wind sensor is mounted to the steel structure the zero position changes For an accurate wind direction a combination of a compass and the wind sensor is used 3 5 3 GNSS GNSS is an abbreviation for Global Navigation Satellite system and it is a type of GPS card This sensor is a board that sends data and position information over his pins The sensor that is available for this project is a SUPERSTAR II For more information on which pins send you the information you can follow the 3 6 CONCLUSION 2E mms Figure 3 15 SUPERSTAR II 7 instructions in the user manual or read the report of Mathias on the data logging part of the project The SUPERSTAR II seen in Figure is a quality GPS receiver used for a variety of embedded applications It has robust signal tracking capability under difficult signal conditions The SUPERSTAR II is a complete GPS OEM sensor that provides 3D navigation on a single compact board with full differential capability It is a 12 channel GPS receiver that tracks all in view satellites and it is fully autonomous such that once power is applied the SUPERSTAR II automatically searches acquires and tracks GPS satellites SU PERSTAR II receivers also have a Satellite Based Augmentation System
78. ne If this parameter is equal to one this means that the sending thread is waiting for a message ok The receiving thread lets the sending thread now the message ok has arrived by making waitingMessageOk zero If waitingMessageOk was already zero instead CHAPTER 7 BASE STATION IMPLEMENTATION print the different options Wait for an input ask for more information about the command if necessary Send the message to the raspberry pi Wait for message ok or timeout Figure 7 1 Sending messages to the Raspberry Pi 7 4 RECEIVING FROM THE RASPBERRY PI Start Is there message coming in No make Yes waitingMessageok Is waitingMessageok equal to 1 Is ita message ok equal to zero Send the current Yes message again Is it a wrong command print the message send a message ok back to the Raspberry Pi Figure 7 2 Receiving messages from the Raspberry Pi 85 86 CHAPTER 7 BASE STATION IMPLEMENTATION receiving broadcast Is there a broadcast message coming in Print the message Figure 7 3 Receiving broadcast messages of one this was probably a lost message ok and the program doesn t do anything with it The thread just goes back to waiting for a new message If the incoming message wasn t a message ok the program checks if it was a wrong command message If this is the case the program sends the current message that the program wa
79. ome country and opening my view on how other cultures live 1 3 General Information A buoy is a partially submerged floating device used in water that can have many purposes It can be anchored stationary or allowed to drift with the sea current 1 2 CHAPTER 1 INTRODUCTION Figure 1 1 Picture of myself Buoys can be found on open sea rivers lakes bays or other bodies of water A buoy can be used for many purposes which divides them into different types col lecting data for weather agencies marking navigation channels providing useful measurements information about their location or signalling dangerous areas or spots Depending on the purpose a buoy can have different chaps and sizes The smallest buoys do not contain any electronic equipment and are used to mark the location of shallow water or an underwater mountain for instance The larger buoys have more equipment on board to give passers or a control station at a certain range specific measurements on that location as exemplified in Figure 1 2 They are mostly equipped with a multitude of electronics such as sensors solar panels and batteries 4 1 4 Project Description This project is in development since two years It was started as an EPS project and two students who did this project as their master thesis then further devel oped it The EPS students were responsible for the design and construction of the hull and the stainless steel structure A picture of this
80. ommand package will be described In Figure 5 1 the general structure of a command package can be seen In Table 5 1 you can see all the possible commands that were defined by now byte n 1 byte n 2 byte n 5 ID complement DataLength n 4 data bytes CRC32 Checksum Figure 5 1 Basic command package 37 38 SOH ASCII SDC not connected Combination Coordinates Wind speed Wind direction dollar sign dollar sign dollar sign conductivity sign sign Data dollar finished sign Water depth Water temperature E dollar p sign dollar sign GNSS not dollar connected sign Wrong dollar command sign sign sign dollar sign dollar sign CHAPTER 5 APPLICATION PROTOCOL Table 5 1 All the possible commands EOH ASCII Datalength Hex Representation IDA Hex ID comp Hex Representation Representation 00 0 00 3 O1 or 02 Ol or 02 O1 or 02 C7 BE 01 or 02 Ol or 02 BA Ol or 02 5 1 COMMAND PACKAGE 39 Table 5 2 Data specifications of the mode on command Data mode on IDE sensors Sensor Time interval __ function hee broadcast protocol mode used hhmmss ss Size B 1 1 X times 1 1 4 1 Mathias Van Flieberge and I added some new functions and some new com mands First of all we changed the original commands regatta mode and environmental mode These c
81. ommands were changed to a mode on and a mode off command The protocol will now be much more flexible to add and remove different modes beside the environmental mode and the regatta It is also more obvious to run multiple modes at the same time The regatta mode and the environmental mode commands insinuated that there was only one mode running at the same time The data length of the mode on command represents the number of bytes in the data part of the message In Table 5 2 there can be seen what kind of parameters that be can found in the data part of the mode on command First of all there is a mode ID number this is just a unique number that represents the mode After this there is the total number of sensors that this mode will use followed by the id of these sensors The next parameter represent whether the mode will broadcast data or not If this parameter is 01 the data will broadcast If it is 00 the data that will be col lected by the STM32F3 Discovery will not be broadcasted and the base station will have to specifically ask for the data The following four bytes represent the time interval This time interval is the time between 2 measurements of a sensor The time interval is presented as hh mm ss ss where hh are the hours mm are the minutes and ss ss are the seconds and hundreds of seconds Every part that was just described represents one byte The last byte of the data pa
82. on should only require changing some parameters in the default setup file There is still room for further improvements to the telemetry and configura tion subsystem e Currently every program is executed in a terminal window and it would be interesting to have a graphical user interface for the base station program e Dueto the absence of a HDMI screen it was not easy to test the Raspberry Pi Wi Fi connection It should be identical to connecting over the Ethernet as long as the Raspberry Pi IP address is known e The program should be tested more so that errors or bugs that were overseen can be fixed as well e Specific tests need to be conducted to determine the power consumption of the master and slave modules e The program should be implemented in the Beaglebone Black instead of the Raspberry Pi because the Beaglebone Black was the chosen master module Bibliography 1 wikimedia commons Horswell rock east cardinal buoy 16 September 2008 cited at p v 3 2 Albaladejo C and Sanchez P and Iborra A and Soto F and Lopez J A and Torres R A low cost sensor buoy system for monitoring shallow marine environments 2014 cited at p v vii 6 7 8 3 Davisnet Picture anemometer 2014 cited at p v 9 4 Hendrick Verschelde report Environmental Regatta Buoy Telemetry and Configuration 2013 cited at p v 2 16 23 27 5 ST STM32F3DISCOVERY 2013 cited at p v 22 6 Trekstor
83. onReceiving function This function is the main function to receive things from the base station It also sends acknowledgment messages back like message ok or wrong command Inputs none Outputs none Description 6 13 8 startBaseStationSending Table 6 9 Info startBaseStationSending function This method is the main function for sending packages that are waiting in the Description dataQueue and dataBroadcastQueue to the base station When it has send a message it also waits for a message ok Inputs none Outputs none 6 13 9 initSTM32F3 Table 6 10 Info initSTM32F3 function This function initializes the serial connection between the Raspberry Pi and the STM32F3 Discovery board If the connection is made openSer is equal to one Inputs none Description 1 connection established Outputs 0 no connection established 6 13 10 startSTM32F3Sending Table 6 11 Info starts TM32F3Sending function This function is the main function of the sending part to the STM32F3 Discovery It looks at the priority queues and the interrupted queue and gets the message with the highest priority out of his queue It then sends the command by calling the functions sendCommandWithData or sendCommandWithoutData Inputs none Outputs none Description 6 13 COMPLEMENTARY CLASSES 75 6 13 11 s Description tartS TM32F3Receiving Table 6 12 Info startSTM32F3Receiving function This is the mai
84. ong data or not a wrong command it must be a normal command If openSer 1 this means the STM32F3 Discovery is 64 CHAPTER 6 RASPBERRY PI IMPLEMENTATION startSTM32F3Receiving quit the program check if there is something coming in from the STM32F3 Is the message good is ita command message Yes Handling send wrong command back put the data in the dataQueue change the state acordingly Figure 6 6 Flowchart for receiving from the STM32F3 Discovery 6 10 SENDING TO THE BASE STATION 65 connected the command is put in the incomingQueue The control thread reads this queue and from there the command is put into the right priority queue The control thread also determines whether a busy command has to be interrupted or not but this feature will be discussed more later on in the report If openSer is not one the STM32F3 Discovery is not connected and the pro gram sends immediately a STM32F3 not connected message back to the base station 6 10 Sending to the Base Station The sending part from the base station communication is basically checking if there is something in the data queue send it and then wait until the receive thread receives a message ok This is done with the variable waiting Message0Ok This thread also checks if wrongData is one because when this happens it means that the Raspberry Pi received a wrong data message from the base station and the data pack
85. onse can t make contact with the STM32F3 we sended 2431CE0112000000240520142AA3D33AA0 again to the STM32F3 times we tried to reach the SIM32F3 1 can t make contact with the STM32F3 we sended 2431CE0112000000240520142AA3D33AA0 again to the STM32F3 times we tried to reach the STM32F3 2 can t make contact with the STM32F3 we sended 2431CE0112000000240520142AA3D33AA0 again to the STM32F3 couldn t access the STM32F3 for three times sleep for 5 seconds In this output file can be seen that the STM32F3 Discovery doesn t respond When the Raspberry Pi tries to send the default mode on command there is no reply We try to re send this message three times before we give up The same happens with the message the Raspberry Pi got from the base station The Raspberry Pi still tries three times to send the message again but then we put a STM Not connected message inside the dataQueue to send to the base station In the output below the base station program can be seen Listing 8 6 output base station program MacBook Pro van Laurens Allart versie 17 laurensallart python baseStation_v10 py created a socket connected Starting Sending thread Starting Receiving thread Starting Receiving Broadcast messages choose one of the following commands and give in the number 10 MODE ON 14 MODE OFF 23 COORDINATES 31 WIND SPEED 36 WIND D
86. or five days without sunlight The user interface is designed to work on a personal computer with LabView Data is extracted and sent by email through a communication system Parameters such as wind speed and direction temperature etc are displayed Further data can be saved and monitored in diagrams to carry out long term research of parameters 11 2 4 2 Technology Design and Operation of an Autonomous Buoy System in the Western English Channel This project is located in Plymouth Marine Laboratory in the United Kingdom Its purpose is to continually monitor the operationally demanding coastal and open shelf environment of the western English Channel A Satlantic Stor X data acquisition and logging system controls the scheduling and data management for the core sensors WQM ISUS CDOM fluorometer above water radiometer and 12 CHAPTER 2 STATE OF THE ART the AirMar meteorologi cal station The Stor X also has three digital and four analog ports available for future expansion with commercially available oceano graphic instrumentation To facilitate greater flexibility the Stor X is con nected using RS232 to an on board PC who effectively forms the control centre of the buoy The on board PC has the following specifications a Geode LX800 CPU run ning at 500 MHz 256 MB DDR RAM an 8 GB solid state disk and Wolvix Linux operating system Linux scripts control the monitoring of the battery supply voltages an on board camera
87. oring system of the buoy They also chose the majority of the components for the overall control and sensing system This year during the first semester two Belgian students Jeroen Vervenne and Hendrick Verschelde worked on the data logging slave control unit as well as on the telemetry and configuration master control unit subsystems and designed the application level communica tion protocol The current thesis continues the development of the telemetry and configuration subsystem This subsystem is responsible for the configuration of the operation mode and selection of sensors as well as for the communication with the base station environmental monitoring boats regatta beacon and with the data logging subsystem The development of the data logging subsys tem which collects and stores in a SD card the selected sensor data proceeds with another Belgian student Mathias van Flieberge The goal of this thesis is to implement the telemetry and configuration sub system in the master control unit and to refine and implement together with Mathias van Flieberge the designed application level protocol In particular the master control unit must handle and assign priorities to the incoming messages from the base station request data from the slave control unit and broadcast messages holding water wind and position real time data in the regatta mode Whereas the master control unit and base station communication and the
88. ormazin Turbidity Unit e NTU Nephelometric Turbidity Units e JTU Jackson Turbidity Unit 2 4 RELATED WORK 11 2 3 2 5 Water pH pH is a measure of the acidity or basicity of a fluid Solutions with a pH less than seven are said to be acidic and solutions with a pH greater than seven are basic or alkaline Pure water has a pH very close to seven It is also important to know that pH has a logarithmic scale 2 3 2 6 Algae and Plankton These sensors measure the amount of algae or plankton particles in the water 2 4 Related Work There are a lot of projects in other universities that have similar capabilities as the buoy project we are working on We will discuss them briefly here 2 4 1 Autonomous Meteorological Buoy This is a project from the Escola Polit cnica Superior d Enginyeria de Vilanova i la Geltr and the Universitat Polit cnica de Catalunya The project is developed to collect weather and sea related data in the Mediter ranean Sea From the buoy the data is send to a base station where it can be processed and the information can be further analysed A smart sensor network is set up based on the IEEE 1451 4 standard and build with a RENESAS 16 bit microcontroller For the communication the Short Burst Data Service of IRID IUM is used The power supply is realized through an autonomous photovoltaic system with storage unit and converters to achieve the required voltage levels The battery provides power f
89. pt socket IPPROTO IP socket IP MULTICAST TTL ttl return 1 except print multicast failed time sleep 5 return 0 There was a new socket object made and it was called sBroadcast this time In the function socket socket other parameters are given along now to create a multicast socket The parameters that are given along with this function are socket AF_INET and socket SOCK_DGRAM There must be noticed that the second parameter is different than the one in the socket for the point to point TCP IP connection The next thing that is done is setting the time to live for messages to 1 This is to make sure the messages stay in the local network and do not go further If there is no error doing all the things that were just described the connection is established and the function can return one If there is an error the program sleeps for a while and returns zero By returning zero the program knows it needs to try again to establish a connection 29 6 7 Sending to the STM32F3 Discovery Now the actual thread that handles the sending part to the STM32F3 Discovery will be discussed In the flowchart in Figure you can see the approach that 60 CHAPTER 6 RASPBERRY PI IMPLEMENTATION was taken The first thing that is done is making the state zero and look if there is a command in one of the queues The thread looks at the queues with the low est priority number first and than to the queues with a higher priority number For e
90. puter The screen the keyboard and the mouse from the laptop will act as those from the Raspberry The command that is used in the terminal is ssh X pi 192 168 1 10 The IP address 192 168 1 10 is the IP address of the Raspberry Pi In the hardware section of the Raspberry Pi you can find the explanation of how this IP address was found The X variable is necessary to start the X11 program to start the user in terface over the Ethernet connection The Raspberry Pi will now ask for the password When the password is given the command shell of the Raspberry Pi will be displayed in the terminal window To start the user interface on the mac the command lxsession can be used All these steps can be seen in Figure after Ixsession was typed in the terminal of the Raspberry Pi the user in terface starts in a X11 window and the desktop of the Raspbian interface can be seen The desktop of Raspbian can be seen in Figure There can also be noticed that the terminal says there are some faults but there hasn t been no ticed any effect of these faults Everything there can be seen is send through the Ethernet connection between the laptop and the Raspberry Pi There can now 4 3 SOFTWARE 33 QO a Pi Store IDLE 3 HDP py o d Python Implernentarl Garnes on_v0 1 py Mliclori generatelo mmrnancl py 1 amp OCR Shutdowr OCR Figure 4 4 Desktop of Raspbian be worked directly onto the Raspberr
91. rong Data CW Conductivity Water TW Temperature Water Combi Combination mode Stop ERROR DATA FINISHED Figure 5 3 Overview of the protocol between the master and the slave units e The master Raspberry Pi sends a message ok back to the base station if the command is valid e If there are no other commands that are being handled at that specific moment The Raspberry Pi forwards the command to the STM32F3 Dis covery e If the communication is ok the STM32F3 Discovery sends a message ok back to the Raspberry Pi e The STM32F3 Discovery can now send data packages to the Raspberry Pi 44 base station CHAPTER 5 APPLICATION PROTOCOL Raspberry Pi STM32F3 Send a com Message ok Figure 5 4 Normal working mode 5 6 USE CASES 45 The Raspberry Pi answers with a message ok to every data package and sends the data package to the base station If the Raspberry Pi get a message ok from the base station it can send the next data package e If there is no more data to send the STM32F3 Discovery sends a data finished package e The Raspberry Pi answers once more with a message ok 5 6 2 Master to Slave Broken Communication Figure 5 5 displays the situation when the communication between the Raspberry Pi and the STM32F3 Discovery is broken We will explain now what happens in this situation on the basis of the Figure e
92. rt is 00 for now but later on this byte can be used to select a different protocol than the one that is ours like for example the NMEA protocol The mode off command has a data length of 03 This was necessary for Mathias Van Flieberge because otherwise it would be too complicated with the 01 and 02 options for one or two dates that are implemented in some other com mands The parameter that is given is the ID number of the mode that we want to close 40 CHAPTER 5 APPLICATION PROTOCOL byte 1 byte 2 CRC32 em Figure 5 2 basic data package Another new command is the data finished command When the Raspberry Pi asks data he will also receive a data finished command when all the data was received This was necessary to implement because the master must know when the data is finished in order to know when he can send the next command The original checksum was too simple not sophisticated enough so there was decided to change this to the CRC32 checksum This means the length of the checksum was doubled from two bytes to four bytes The CRC32 checksum will be discussed further in this report 5 2 Data Package The data package differs slightly from the command package The SOH is again the dollar sign The ID stands for the ID number of the data package There are two different ID values one for the broadcast data message 0B and one for the normal data message 07 This is followed by the t
93. ry is not connected The message we were trying to send is being saved in the interrupted queue and the thread sleeps a predefined number of time before the program will try again When the program does receive a message ok the thread goes in a waiting state to receive data If a data package has arrived a message ok is send back If a datafinished message is received a message ok is send back and the program returns to the main thread There must noted that this thread does not do the receiving of the packages but you can know there was for example a message ok or a data package received by looking at the current state of the state machine 6 7 SENDING TO THE STM32F3 DISCOVERY StartSTM32F3Sending stateSTM 0 Is there a command in one of the queues take the command out of the queue put command back in his queue and take the e command out of the priority interruptedQueue interrupted Queue higher stateSTM 1 Does the command require data Send No command without data Yes Send command with data Figure 6 4 Flowchart for sending to the STM32F3 Discovery 61 62 CHAPTER 6 RASPBERRY PI IMPLEMENTATION send command with data Send the command change stateSTM to 3 wait until message ok received or timeout put a STM Not put the command Yes connected in the in the interrupted change the state to O
94. s complement of the checksum This way the checksum Mathias Van Flieberge had implemented in the data logging part of this project is equal to our checksum 5 5 Overview When we look at Figure 5 3 the different messages that can be send between the Raspberry Pi and the STM32F3 Discovery can be seen The messages on the left side are the message that can be send from the STM32F3 Discovery to the Raspberry Pi the messages on the right side are messages that are send the other way around There can be noticed that the messages are divided in groups On the left side there is the error group the data messages the message ok and the data finished These groups exist because the messages in the same group are treated the same Messages from different groups require a different action when the Raspberry Pi receives them On the right side there is the error group mode group data group this is not the data message but the commands that request data and the message ok 5 6 Use Cases 5 6 1 Error Free Communication Figure represents the normal working mode where there are no errors or unexpected behaviours Now let us explain the Figure a little bit more in detail e First the base station sends a command to request data to the master Raspberry Pi 5 6 USE CASES 43 ERROR DATA SD SDC not connected CD Coordinates NS GNSS not connected WS wann speed WD Wind direction WC Wrong Command DW Depth Water WD W
95. s handling to the Raspberry Pi again If the in coming message was neither of the previous messages the program checks if the message is valid and it prints its properties on the screen After this a message ok is send back to the Raspberry Pi The thread can now listen again to new incoming information f 5 Receiving Multicast Messages The receiving of multicast message is also an important part of this report because this can also be implemented in future hardware modules that require informa tion from the buoy This method is especially important in the regatta mode A general approach can be found in Figure 7 3 7 6 CONCLUSION 87 In Figure can be seen that this thread is the easiest so far because these multicast messages do not need acknowledgement When the program receives multicast data it just checks if the message is valid or not If the message is valid the program prints it on the screen If not these messages are just thrown away There are no message ok wrong command orwrong data messages send back 7 6 Conclusion In this chapter the implementation was clarified with some important flowchart of the operation of the different threads The different python functions were summed up with some information of what they do and which inputs and outputs they use The initialization of both the serial and the TCP IP connection was explained and provided with some python code We didn t include the whole code in here because
96. st to host communication and the application layer which pro vides process to process application data exchange 26 The TCP IP protocol will be used in the program to connect the Raspberry Pi with the base station A multicast will be used for sending a data packet in regatta mode to everybody that is interested More information on how to implement this in Python will follow further on in this report 4 5 Conclusion In this section the different software tools that are used in order to implement the desired goals were presented We now have a basic idea of which programs operating systems and programming languages are used and how they are used Some of them will be explained a little bit more in other sections of the report Chapter 5 Application Protocol In this section the protocol that s used for the communications between the Rasp berry Pi and other modules will be explained A new protocol was needed for the communication between the master Beagle bone Black or Raspberry Pi and the slave the STM82F3 Discovery and also for the communication between the master and the base station The students who worked on the project in the previous semester designed a new protocol but because we made a lot of changes on this protocol all the possible commands and data packages will be presented here again There are some messages that were added and others were deleted or modified 5 1 Command Package In this section the c
97. station e main control thread 6 2 General Architecture A general representation of the buoy s architecture can be found in Figure We can see the master slave configuration of the buoy and the connections over Wi Fi to the base station and the regatta boats In Figure 6 2 a more detailed architecture of the master module can be seen We see the connections to a Wi Fi module which is a Wi Fi dongle connected through USB to the Raspberry Pi And the serial connection to the STM32F3 ol 92 CHAPTER 6 RASPBERRY PI IMPLEMENTATION Base Station Regatta boats Cae ss Ee i a a gt ee lt P l y My e yg Raspberry Pi BeagleBone Black STM32F3 DISCOVERY Sensors B Figure 6 1 General architecture of the buoy Discovery is done by the USB port of the Raspberry Pi Inside the master module we have five threads 2 threads for the serial communication one for listening and one for sending and 2 for the wireless communication over Wi Fi The last thread is a main control thread 6 3 States We will start here with a theoretical analysis of the communication between the master and the slave This includes the receiving and sending from and to the 6 3 STATES 53 Raspberry Pi Beaglebone Black 5 threads 1 control 2 wifi communication 2 serial communication Master module Priority Queues Figure 6 2 Architecture of the master module Wifi module Command STM32F
98. t AF INET and socket SOCK STREAM This will create a socket for a point to point connection with the Raspberry Pi The next action is to set the timeout of the connection This timeout TCP TIMEOUT is defined in the defaultsetup py file and is set at the moment to three seconds After this there will be tried to connect to the host with the connect function The host is defined in the defaultsetup file as well as the port number The host is equal to the IP address of the Raspberry Pi If this succeeds there will be a one returned otherwise a zero is returned back to the main thread and the program will sleep for 5 s until it will try again to connect 28 1 2 Multicast Initialization The code for the initialization of the multicast mode is provided below This code will start up a new socket so the base station can receive multicast messages There must also be noted that this initialization can also be used to implement in other devices that are interested in these multicast messages 29 def initBroadcast global sockBroadcast try Create the socket sockBroadcast socket socket socket AF INET socket SOCK DGRAM Bind to the server address sockBroadcast bind defaultsetup SERVER ADDRESS Tell the operating system to add the socket to the multicast group on all interfaces group socket inet aton defaultsetup MULTICAST GROUP mreq struct pack 4sL group socket INADDR ANY sockBroadcast setsockopt socket I
99. the threads when there is an error To start the thread you type baseStationSending start main baseStat ionSending baseStationSending baseStationSending daemon True baseStationSending start fm thread to send messages and data to the base station class baseStationSending threading Thread def init self threading Thread init self def run self startBaseStationSending 6 13 5 startControl Table 6 6 Info startControl function This function is the main function for the control thread The most important Description activity is to put the messages that the program got from the base station and that are waiting in the incomingQueue in the right priority queue Inputs none Outputs none In the next sections of the report each function that is present in the program is summed up Information about these functions and in and outputs can be found in the tables that come along with the subsections 6 13 6 initBaseStation Table 6 7 Info initBaseStation function This method does the initialization of the TCP IP connection between the Raspberry Pi and the base station It creates a socket and listens to the connection meme request from the base station If the connection successes this function makes the openTCP variable equal to 1 Inputs none Outputs none 74 CHAPTER 6 RASPBERRY PI IMPLEMENTATION 6 13 7 startBaseStationReceiving Table 6 8 Info startBaseStati
100. the water This out of the water part always includes an antenna for RF transmission optionally a harvesting system solar panel Eolic generator etc to supplement the power source and in some cases one or more external sensors essentially to monitor meteorological data wind speed air temperature atmospheric humidity etc Figure 2 1 illustrates the generic architecture of an autonomous buoy 2 2 2 Communication Network physical topology and density are entirely application dependant You need to know the environment in which the buoy will be active There are differ ent possibilities to interact with the base station or with other sensor node in a wireless sensor network WSN There are a lot of different communication tech nologies you can use Every topology has its own characteristics which determine whether or not it is more suitable than others in terms of attributes of network functionality such as fault tolerance connectivity etc For communication it is possible either to develop communications protocols on the data linking layer us ing different medium access mechanisms such as TDMA FDMA and CSMA or else to use different wireless communication standards and technologies The most important ones are summed up in Table 2 1 For wireless communication the sensor node incorporates a radio module which is chosen to suit the desired range Sometimes in order to increase the range range extenders for RF transc
101. to the base station over a wireless connection It should also be possible to send broadcast messages to everyone who is interested in those messages and who is connected in the same network The master should also be able to send and receive messages and data from the slave module It should be able to analyse those messages and data and apply some kind of priorities in such a way that more important messages are handled first Chapter 2 State of The Art In this section there will be an overview of which technologies are being used at the moment in other researches or in actual buoys that are on the market 2 1 Introduction At the moment a lot of research is done on smart autonomous buoys which communicate with a base station or with each other Monitoring of the marine environment has come to be a field of scientific interest in the last fifteen years The instruments used in this work have ranged from small scale sensor networks to complex observation systems Wireless sensor networks have become cheaper and they are easy to deploy Autonomous buoys are mostly used to monitor coastal marine ecosystems in real time They measure the effects human activity attendant on industrial tourist and urban development New information and communication technologies offer new perspectives and new solutions for mon itoring such ecosystems Research on oceanographic environments offers new challenges different than those on land Som
102. tructuur ontworpen en gebouwd en ze hebben ook het bevestigingssysteem van de boei geselecteerd en samen gesteld Verder hebben deze studenten ook de meerderheid van de componenten gekozen voor de algemene controle en het sensor systeem Dit jaar tijdens het eerste semester hebben twee Belgische studenten Jeroen Vervenne en Hendrick Ver schelde verder gewerkt aan dit project De ene aan het data logging gedeelte slave module de andere aan het telemetrie en configuratie gedeelte master module Zij definieerden ook het application level communication protocol Deze thesis bouwt verder op de ontwikkeling van het telemetrie en configuratie sub systeem Dit subsysteem is verantwoordelijk voor de configuratie van de operatie mode en het selecteren van sensoren maar ook voor de communicatie tussen het base station environmental monitoring de boten regatta beacon en het data logging subsysteem Het uitwerken van het data logging subsysteem dat sensor vil data vergaart en op slaat op een SD kaart wordt gedaan door een andere Belgis che student Mathias Van Flieberge Het doel van deze thesis is het implementeren van het telemetry en config uratie subsysteem in een master control unit en om verder uitwerken en imple menteren van het ontworpen application level protocol samen met Mathias Van Flieberge In het bijzonder moet de master module in staat zijn om inkomende berichten van het
103. was there a timeout dataQueue Queue No send message ok Yes back and change stateSTM to 4 send message ok is stateSTM 6 Yes back is quit 0 stateSTM 4 stateSTM 5 and STMTimeout lt 3 return Yes Figure 6 5 Flowchart for sending a command to request data from the STM32F3 Discovery 6 8 RECEIVING FROM THE STM32F3 DISCOVERY 63 6 8 Receiving from the STM32F3 Discovery The receiving part of the STM32F3 Discovery communication is not very difh cult The flowchart can be seen in Figure The first thing that is done is again looking at the quit variable If this is one the thread will be terminated The next thing that is done is checking if there is something coming in from the STM32F3 Discovery It will be checked if it is a message a good message If this is the case the function command handling is called The function command handling checks the command that has arrived and changes the state accord ingly It also takes the current state into account If it is not a command but a data package the thread does the same except this time the function data handling is called 6 9 Receiving from the Base Station The base station communication threads are different than the STM32F3 Dis covery communication threads First of all there is no state machine but there is a shared variable waitingMessageOk This parameter is equal to one when the thread is waiting for a m
104. will be defined This timeout can also be defined in the defaultsetup py file If one of these actions that were just described fails there will be displayed that the connection has failed and waited a predefined amount of time If it didn t fail the function will go to the second part of setting up the connection 28 Once the socket is setup correctly the program will listen to incoming con nection requests by other users The base station now has to send a request 6 7 SENDING TO THE STM32F3 DISCOVERY 59 There will be only listened to one request If the request came in from the base station the program saves the clients name and his address The connection is now complete and there can be messages received from this client The variable open TCP will be one if the connection is complete This also is a global variable so other threads can check if the connection is established 6 6 2 Multicast Initialization For the regatta mode the possibility is needed to send data messages to everybody that is interested This is done by multicasting the message To do this building a new socket that can handle multicasting is needed The code that does all this can be found below def initBroadcast global sbroadcast try sbroadcast socket socket socket AF INET socket SOCK DGRAM Set the time to live for messages to 1 so they do not go past the local network segment ttl struct pack b 1 sbroadcast setsocko
105. xample the first priority queue we check is the queuel Then a comparison whether there is a command in the interrupted queue that has a higher priority or not is done The command with the highest priority is taken out of his queue There is an analysis of the command and the program looks if this particular command needs data from the STM32F3 Discovery or not If this is the case the subroutine send command with data is launched otherwise the subroutine send command without data is started Only the send command with data subroutine will be discussed here since the send command without data is the same as the other one but it returns back to the main thread when it receives a message ok You can see the flowchart for the send command with data subroutine in Figure The first thing that is done is the actual sending over the serial link and change the state accordingly In the send Command With Data subrou tine the state will become 3 In the send Command Without Data the state will become 7 If the message reaches the STM32F3 Discovery it will send a message ok back So the program waits until a message ok is received The waiting is of course limited in time If this timeout is reached the thread will send the message again and wait again This is done three times if there is still no message ok from the STM32F3 Discovery a message is send back to the base station that the STM32F3 Discove
106. y Pi There must be noted that on windows computers you can also use the application Putty to connect to the Raspberry Pi over SSH 25 4 3 3 CoolTerm CoolTerm is a simple serial port terminal application no terminal emulation that is geared towards hobbyists and professionals with a need to exchange data with hardware connected to serial ports such as servo controllers robotic kits GPS receivers microcontrollers etc Roger Meier created it and it is available for most common operating systems This little program was used to test serial communication between the Rasp berry Pi and the laptop It is possible to view received message from the Rasp berry Pi in ASCII code characters or as hexadecimal numbers You can also send messages back to the Raspberry Pi in ASCII code or give in the numbers hexadecimal A screenshot of the program can be seen in Figure 34 CHAPTER 4 PROJECT DEVELOPMENT TOOLS 000 CoolTerm O a D rt ar mm ES bos AW of 1691 New Open Save Connect Disconnect Clear Data Options View Hex Help Serial Port Serial Port Options Port Bluetooth Modem Baudrate 9600 Miscellaneous Data Bits 8 Parity none Stop Bits 1 Flow Control CTS DTR XON Initial Line States when Port opens DTR On DTR Off RTS On RTS Off Re Scan Serial Ports iPhonevanjefRoosens Wir 9600 8 N 1 y TX O RTS DTR DCD Disconnected J RX CTs DSR 2 RI Figure 4 5 Printscreen of t

Environmental/Regatta Buoy: Telemetry and Configuration

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