AN0504 Tag Design with swarm bee LE
Contents
1. pa p ED mmm E En e STEEN SC Des AN0504 Tag Design with swarm bee LE 1 2 NA 14 0267 0005 1 2 Application Note ana not ron AN0504 Tag Design with swarm bee LE TECHNOLOGIES Version 1 2 Author JDI Document Information Document Title AN0504 Tag Design with swarm bee LE Document Version 1 2 Current Date 2015 11 02 Print Date 2015 11 02 Document ID NA 14 0267 0005 1 2 Document Author JDI Disclaimer Nanotron Technologies GmbH believes the information contained herein is correct and accurate at the time of release Nanotron Technologies GmbH reserves the right to make changes without further notice to the product to improve reliability function or design Nanotron Technologies GmbH does not assume any liability or responsibility arising out of this product as well as any application or circuits described herein neither does it convey any license under its patent rights As far as possible significant changes to product specifications and functionality will be provided in product specific Errata sheets or in new versions of this document Customers are encouraged to check the Nanotron website for the most recent updates on products Trademarks All trademarks registered trademarks and product names are the sole property of their respective owners This document and the information contained herein is the subject of copyright and intellectual property rights under international convention2. All rights reserved No part of this document may be reproduced stored in a retrieval system or transmitted in any form by any means electronic mechanical or optical in whole or in part without the prior written permission of Nanotron Technologies GmbH Copyright 2015 Nanotron Technologies GmbH Page 2 Doc ID NA 14 0267 0005 1 2 2015 All Rights Reserved ana not ron Application Note TECHNOLOGIES AN0504 Tag Design with swarm bee LE Version 1 2 Author JDI Contents tt Tieden EE 5 2 Tag Building BlOCKS c ccsseeccrsseeegsesstee ce stipa pa e pa RADE Eaa nee css Ea EEA EG 6 23 Ve AMINA EE 6 2A 1e ChipAMenna EE 6 2 1 2 UEL Standard Connector ceceeecceceeeeeceeeeeeeeeeeceaeeeeeeeceaeeeeaeeseaeesnaeeseaeesaeeseaeeesaeeseaeeeseeeseeeenates 7 Se TMAMSCOIVG E cece tere Eecher Eesbech petue die eatueae wiser ads EE ve EES EE EE 8 2 3 Optional THOST ci 5 sade heck he hccce dae case Nias cate Eeer 8 2 9 1 Basi Tag Functionality EE EE 8 2 3 2 Extended Tag Functionality with a Host Microcontroller AAA 8 24 Power SUPPLY EE 8 ee EE 8 2D HOUSING EE 8 3 Utilizing Swarm DGG aS a Tag EE EE 9 3 1 Tag without Host Controller AA 9 3 2 Tag with Host CGontroller AAA 9 4 Power Managements sted cue senda ianen cats E det pada denrea paoa a a ea aana rea Eea E Ae Eea NERES 10 4 1 Power le reann aaaea ces aae aaa a a Aaa pa a e Aa aA a eE A E O a aaaea aa 10 4 2 Calculating Power CONSUMPTION e ceeeceeeeeee
3. as temperature humidity etc must be taken into consideration to choose the right material of the housing Page 8 Doc ID NA 14 0267 0005 1 2 2015 All Rights Reserved ana not ron Application Note TECHNOLOGIES AN0504 Tag Design with swarm bee LE Version 1 2 Author JDI 3 Utilizing swarm bee as a Tag According to application requirements a swarm bee tag can be designed as a tag without host controller or as a smart tag with an external host controller 3 1 Tag without Host Controller Figure 3 1 shows a possible configuration of swarm bee tag for stand alone operation with a chip antenna When an external host is connected i e for debugging purpose the same signal level restrictions are valid as for tag configuration with internal host swarm bee module 2 VIN RF PORT 13 3 GND ee Figure 3 1 autonomous tag without host controller Note for a full list of pin description MOD EN UART_TX etc please refer to 3 3 2 Tag with Host Controller Figure 3 2 shows a possible configuration of swarm bee as a tag with host The power supply voltage range for swarm bee must be within 3 V 5 5 V The host may have the same or a different power supply voltage Important are the correct levels of digital signals between swarm bee and the host By pulling pin 6 MOD EN to logical LOW the swarm bee LE module can be completely disabled In this case the module draws a current of less than 1uA The swarm bee LE
4. efficiency 90 the approximate battery lifetime T4 can be calculated as follows 1200 mAh 90 T4 _ 1200h 900 As 1s Note To simplify the approximate calculation the power down consumption has been neglected For an accurate calculation of the battery lifetime this parameter must be considered It dominates for long phases of sleep between blinks 4 3 3 Combined Location Modes Depending on requirements of an application swarm bee tags may be used for combined location modes i e in areas where relative location information is needed between radio nodes a tag must range with other 2015 All Rights Reserved Doc ID NA 14 0267 0005 1 2 Page 11 Application Note z2nanotron AN0504 Tag Design with swarm bee LE TECHNOLOGIES Version 1 2 Author JDI tags in order to avoid collisions or dangers In other areas a tag may just need to send its own node ID blink so that the server can detect the position of this tag In this case the battery lifetime of a tag can be calculated combining parameters for both collaborative and fixed location 4 4 Battery Monitoring In order to monitor the battery voltage level the voltage can be read out through a voltage divider which is connected to Pin 24 of the module as shown in Figure 4 3 Two resistors of 2 2 MO and 2 7 MQ are required for the circuit 2 7 MQ must be connected to VIN battery voltage 3 5 5 V and 2 2 MO to GND Depending on battery voltage th
5. 450AT43A100 Figure 2 2 chip antenna on a two layer PCB A chip antenna needs to create a 50 Ohm load impedance The matching networks can be usually found in the data sheet of the chip antenna A T matching network is widely used to meet most application requirements see Figure 2 3 Please pay attention to the following during design of antenna matching circuit Page 6 Doc ID NA 14 0267 0005 1 2 2015 All Rights Reserved ana not ron Application Note TECHNOLOGIES AN0504 Tag Design with swarm bee LE Version 1 2 Author JDI Antenna Johanson 2450AT43A100 z2 Figure 2 3 sample matching network of chip antenna Itis recommended to choose low pass i e Z1 and Z3 as inductor and Z2 as capacitor The typical range of inductor is 1 nH 8 2 nH and as for capacitor 0 2 pF 2 7 pF If serial matching components Z1 and Z3 are not needed they can be replaced by 0 R resistors If Z2 is not needed it must be left open The leading line to the antenna must have a 50 Ohm impedance Itis recommended to use special RF components with SMD type the size of which should not be larger than 0402 metric code The PCB material and layout must be taken into consideration It is recommended to measure the related parameters in an RF Lab to get an optimized design Certain area surrounding the antenna must be free of circuitry Generally the minimum is 3 mm see Figure 2 2 for example The dimensio
6. a Virtual Safety Zone which protects tagged people and animals Robust wireless Chirp technology underpins nanotron s offering of chips modules and loss protection software for indoor and outdoor environments world wide nanotron TECHNOLOGIES be in accordance with applicable regulations Hospitals or health care facilities may be using equipment that is sensitive to external RF energy With medical devices maintain a minimum separation of 15 cm 6 inches between pacemakers and wireless devices and some wireless radios may interfere with some hearing aids If other personal medical devices are being used in the vicinity of wireless devices ensure that the device has been adequately shielded from RF energy In a domestic environment this product may cause radio interference in which case the user may be required to take adequate measures CAUTION Electrostatic Sensitive Device Precaution should be used when handling the device in order to prevent permanent damage reasonable protection against harmful interference in a resi dential installation and against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio fre quency energy and if not installed and used in accordance with the instructions as provided in the user manual may cause harmful interference to radio communications However there is no guarantee that interference will not occur
7. asily be replicated by the user for rapid prototyping and quick time to market Design recommendations are provided with regards to antenna design power management and mechanical design Calculation examples help to estimate battery life depending on application specific parameters like the location blink rate 2015 All Rights Reserved Doc ID NA 14 0267 0005 1 2 Page 5 Application Note ana not ron AN0504 Tag Design with swarm bee LE TECHNOLOGIES Version 1 2 Author JDI 2 Tag Building Blocks A swarm bee tag as shown in Figure 2 1 mainly comprises the following blocks antenna transceiver optional host power supply and housing Housing swarm bee LE S Power Supply Antenna Figure 2 1 general building blocks of a swarm bee tag 2 1 Antenna The swarm bee RF interface is a standard 50 Ohm RF port which requires a 50 Ohm load for optimal RF performance It is possible to connect antennas via RF connectors like U FL as well as printed PCB antennas or chip antennas The RF port is DC decoupled Note There are specialized companies who can help with specific antenna designs In case you need to optimize your antenna solution while meeting certain mechanical constraints you may want to consult with them 2 1 1 Chip Antenna There are a lot of manufacturers who provide 2 4 GHz chip antenna for example Antenova Murata Taiyo Yuden TDK Yageo Johanson etc Figure 2 2 shows a chip antenna from Johanson type 2
8. configured for electromagnetic compatibility To avoid electromagnetic interference and or compatibility conflicts do not use this device in any facility where posted notices instruct you to do so In aircraft use of any radio frequency devices must FCC User Information Statement according to FCC part 15 19 This device complies with Part 15 of the FCC Rules Operation is subject to the following two conditions 1 this device may not cause harmful interference and 2 this device must accept any interference received including interference that may cause undesired operation Statement according to FCC part 15 21 Modifications not expressly approved by this company could void the user s authority to operate the equipment RF exposure The internal external antennas used for this mobile transmitter must provide a separation distance of at least 20 cm from all persons and must not be co located or operating in conjunction with any other antenna or transmitter Statement according to FCC part 15 105 This equipment has been tested and found to comply with the limits for a Class A and Class B digital device pursuant to Part 15 of the FCC Rules These limits are designed to provide About Nanotron Technologies GmbH Nanotron provides reliable loss protection technology and solutions that are used to protect people and animals Energy efficient battery powered wireless nodes are the key building blocks These small devices create
9. e nanoLOC integrated circuit operates in the freely accessible 2 4 GHz ISM band Please refer to 1 for more information about the nanoLOC transceiver 2 3 Optional Host The swarm bee LE module supports a number of basic tag functionalities like periodical transmission of Node ID broadcast To utilize the basic tag functionality the module can be operated in stand alone mode as shown in Figure 3 1 If extended tag functionality is required swarm bee LE should be used in conjunction with a host microcontroller Using a microcontroller also provides more flexibilty to configure the tag for different modes of operation In most cases the performance of a small low power 8 bit controller will be sufficient The configuration as a tag with or without controller is done by pulling pin 4 A_MODE of swarm bee LE to ground or leaving it open set A_MODE to HIGH respectively Please refer to Figure 3 2 Note With the latest swarm firmware from V2 1 1 onwards it is still possible to use UART when A_MODE is set to HIGH In this case UART wakes up periodically together with the device 2 3 1 Basic Tag Functionality Tags based on a stand alone swarm bee LE module are suitable for collaborative and fixed location applications They are able to transmit location broadcasts and respond to ranging requests Most recent readings from the on board MEMS and temperature sensor are transmitted in each of the location broadcasts as payload Please refer to 3 f
10. eeeeeseeeeeeaeeteaeeseaeeteaeeeaeeteaeeeeaeeseaeeeeaeeseaeeseaeeteaeeeeaeetes 10 4 3 Battery eme be EEEEEe AER ye aare eais aaee a a AENA AEEA EN TANE ENEE A EEEE AE 10 4 3 1 Collaborative Location Pangimg 10 4 3 2 Fixed Location TDOA o ccccccisaseccasesnaseeseneedeiceaeesceasbbcadearssctensndecseeepueessucpteesdenstenadeesescepastasecaengae 11 4 3 3 Combined Location Modes sirisser naene iaa is en ensa es tae 11 4 4 Battery MOmmtOring isccectececestaseccdediccncees dedi EE EEER an E AAE AAE AEA AA E AAA EE AAN EEA EAEE 12 5 Module Dimension amp Soldering Information 13 5 16 Mod le RE TEE 13 E ee el 13 5 3 Recommended Landing Pattern ccccesecceceseecceeeseneeeeeseeeeeeseeeeseseneeeeeseeenseseaeesesenseeseseeeeeeseesenes 14 5 4 Soldering Information ceeceecceceeceeeneeceneeeeneeeeeeeeeeeeeaeeceaeeeeaeeesaeeeeaeeseeeeeeeseeeseeeseeesseeeseneeeeeeeeeaes 14 6 Firmware Update EE 15 Te AEE EE E E E T 16 2015 All Rights Reserved Doc ID NA 14 0267 0005 1 2 Page 3 Application Note z 2nanotron AN0504 Tag Design with swarm bee LE TECHNOLOGIES Version 1 2 Author JDI List of Figures Figure 2 1 general building blocks Of a swarm bee og 6 Figure 2 2 chip antenna on a two layer DCH 6 Figure 2 3 sample matching network of chip amtemna A 7 Figure 2 4 DEL connector Optreeg ee eege N R R N N EREE E ek ENEE 7 Figure 3 1 autonomous tag without host controller A 9 Figure 3 2 tag with host CONt
11. ere is a permanent power consumption over the voltage divider with a little less than 1A To avoid wrong results of battery value this voltage divider with the two resistors mentioned above must be used If it is not necessary for the user to get the voltage value the voltage divider may be spared In this case the Pin 24 must be connected to GND permanently If Pin 24 is left open any values can be read out as battery voltage values which are wrong values VIN R 2 2MQ R 2 7MO swarm bee LE Figure 4 3 connection of a voltage divider to swarm bee LE Note For a full list of pin description e g GPIO pins please refer to 3 Page 12 Doc ID NA 14 0267 0005 1 2 2015 All Rights Reserved ana not ron Application Note TECHNOLOGIES AN0504 Tag Design with swarm bee LE Version 1 2 Author JDI 5 Module Dimension amp Soldering Information 5 1 Module Dimension 3 5 0 3mm 24 0 2mm 40 0 2mm Figure 5 1 swarm bee LE module dimensions 5 2 Footprint a 1 2mm io Dmm 2 0mm 16 5mm en migom nd 18 8mm Deg 37 6mm Figure 5 2 swarm bee LE module footprint 2015 All Rights Reserved Doc ID NA 14 0267 0005 1 2 Page 13 Applicati
12. in a particular installation Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his or her own expense If this equipment does cause harmful interference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures 1 reorient or relocate the receiving antenna 2 increase the separation between the equipment and receiver 3 connect the equipment into an outlet on a circuit different from that to the connected equipment and 4 consult the dealer or an experienced technician for help Headquartered in Berlin Germany Nanotron Technologies GmbH was founded in 1991 and is an active member of IEEE Further Information For more information about products from Nanotron Technologies GmbH contact a sales representative at the following address Nanotron Technologies GmbH Alt Moabit 60 10555 Berlin Germany Phone 49 30 399 954 0 Fax 49 30 399 954 188 Email sales nanotron com Internet www nanotron com
13. module can be enabled by setting pin 6 to HIGH with a level from 1 5 V to VDD of swarm bee Note Pin 6 MOD_EN must never be left open A pull down resistor should be connected to it The value of this resistor should not be higher than 10 of the internal pull up resistor connected to pin 6 swarm bee module 2 VIN RF PORT 13 lena aannarcananscncnesscuccsasescncsncsccseconenosed Figure 3 2 tag with host controller 2015 All Rights Reserved Doc ID NA 14 0267 0005 1 2 Page 9 Application Note ana not ron AN0504 Tag Design with swarm bee LE TECHNOLOGIES Version 1 2 Author JDI 4 Power Management The swarm bee LE module can go to sleep and only wake up periodically for a short time in order to save battery power The underlying power management concept enables cooperation between the radios of a larger swarm even if they sleep most of the time 4 1 Power Modes With regards to its power consumption a swarm bee LE module can be used either managed or unmanaged There are three different power modes which are controlled by hardware and software simultaneously see Table 4 1 Table 4 1 Power Modes of swarm bee LE Power mode A_MODE pin Power Meaning Power Dow Consumption EE Mode Oo o o r so o For a detailed description of the power modes please refer to 3 4 2 Calculating Power Consumption Power consumption depends on the tag design the use of power modes the location update rate and the loca
14. ns are in mm 2 1 2 U FL Standard Connector Alternatively an external antenna can be chosen for the swarm bee tag It can bee connected to swarm bee LE module through a 2 4 GHz RF connector on the carrier board of the module A widely used connector of this kind is a U FL R SMT connector see Figure 2 4 A proper RF cable must be chosen to connect an antenna via U FL connector Pay attention to the following when using U FL connectors The leading line from swarm bee LE module to U FL connector must be as short as possible The leading line must have a 50 Ohm impedance The leading line must be embedded in GROUND No signal lines shall run in the PCB layer directly under the connector Adjacent ground planes in different PCB layers must be connected with as many vias as possible The ground frames surrounding the UEL connector must be at least 5 mm away from the via lines The area of the layer directly under the U FL connector must be designed as GROUND Figure 2 4 shows a U FL connector with a curved leading line on a PCB Figure 2 4 U FL connector on a PCB 2015 All Rights Reserved Doc ID NA 14 0267 0005 1 2 Page 7 Application Note ana not ron AN0504 Tag Design with swarm bee LE TECHNOLOGIES Version 1 2 Author JDI 2 2 Transceiver In each swarm bee LE module the key block of a swarm bee tag there is a nanoLOC TRX transceiver chip based on nanotron s CSS Chirp Spread Spectrum technology Th
15. on Note ana not ron AN0504 Tag Design with swarm bee LE TECHNOL Version 1 2 Author JDI 5 3 Recommended Landing Pattern The same dimensions for the solder paste screen are recommended depending on the solder screen thickness SLL 20 5 E E ES Ee Seen See gen Pi wai ae a ao IC Seen Eesen de ATT I i oe oo E eg Figure 5 3 swarm bee LE module footprint and landing pattern top view 5 4 Soldering Information For lead free reflow soldering the following conditions are recommended max Solder Peak Temperature 200 C Solder Paste for example ALPHA CVP 520 Page 14 Doc ID NA 14 0267 0005 1 2 2015 All Rights Reserved Application Note ad na not ro n AN0504 Tag Design with swarm bee LE T E C H NOLO GIES Version 1 2 Author JDI 6 Firmware Update The swarm bee LE module is delivered with the latest firmware An update of the firmware is possible through the host interface see 4 for more information 2015 All Rights Reserved Doc ID NA 14 0267 0005 1 2 Page 15 Application Note ana not ron AN0504 Tag Design with swarm bee LE TECHNOLOGIES Version 1 2 Author JDI 7 References 1 nanoLOC Data Sheet V2 01 as of 23 04 2008 Doc ID NA 06 0230 0388 2 01 2 swarm bee LE Data Sheet V1 2 as of 10 04 2015 Doc ID NA 14 0267 0002 1 2 3 swarm API V2 2 as of 08 10 2015 Doc ID NA 13 0267 0003 2 2 4 swarm bee LE Firmware Update U
16. or a complete list of pre set parameters The tag can be powered down periodically by pulling MOD_EN low Figure 3 1 2 3 2 Extended Tag Functionality with a Host Microcontroller Together with a host microcontroller the swarm bee LE module offers several location communication and configuration options beyond the basic tag functionality In this configuration a tag user interface for instance a buzzer and or push buttons can be implemented 2 4 Power Supply swarm bee LE supports the supply voltage range between 3 0 V and 5 5 V Direct supply from primary or rechargeable batteries is possible as well as external supply via USB 2 4 1 Logic Levels Regardless of the power supply voltages of swarm bee LE and host the digital signal levels from host and module are subject to the following restrictions relative to the swarm bee LE module VIL input voltage low max 0 7 V VIH input voltage high max 2 8 V VOL output voltage low max 0 45 V VOH output voltage high min 2 15 V ET Input five volt tolerant input max 5 5 V For pin configuration and supply voltage range of swarm bee LE please refer to 2 If host and module work from different supplies level shifters might be necessary 2 5 Housing The swarm bee LE module together with an optional host is usually mounted onto a carrier board which including or excluding power supply is then put into a housing to build a tag Operating conditions such
17. ot changed the approximate battery lifetime Tez for ranging to two tags can be calculated as follows 1200 mAh 90 sen ee 200 1200 300 pAs 10 s T2 Similarly the approximate battery lifetime T3 for ranging to three tags can be calculated as follows 1200 mAh 90 a 6000 1200 300 2 pAs 10s 3 Ranging with just one tag provides proximity information only ranging values from two tags can be used to determine lateral location information and ranging with three reference tags allows to calculate a 2D location value Note To simplify the approximate calculation the power down consumption has been neglected For an accurate calculation of the battery lifetime this parameter must be considered Specifically for long ranging intervalls this component might even dominate 4 3 2 Fixed Location TDOA swarm bee tags can be used for fixed location as well see Figure 4 2 During fixed location a moving tag sends out its node ID blink regularly Anchors on fixed points receive the blinks and forward them to the location server which calculates the location of the tag based on TDOA time difference of arrival Figure 4 2 fixed location of a swarm bee tag For this application the power consumption of a tag mostly depends on the blink interval and it is much lower than in collaborative location The measured value for each blink is about 900 pAs If the blink interval is 1 s the battery capacity 1200 mAh and the battery
18. rOM OL AAA 9 Figure 4 1 collaborative location Of swarm bee taQS eeescceeeseeeeeeeneeeeeeeeeeerenaeeeeteaeeeeeeneeeseneeeeeseeteneeaaes 10 Figure 4 2 fixed location Of a swarm bee tag 0 eeeeeeeeeseeeeeeneeeeeeneeeeeeeneeeeeeaaeeeeeaeeeeseaeeeeesaaesesenaeeeeneaeterseaaes 11 Figure 4 3 connection of a voltage divider to swarm bee LE eeeeseeeeeeneeeeeneeeeeeeeeeeeneeesenaeeeeseeterenaaes 12 Figure 5 1 swarm bee LE module dimensions ssssnsssssssssrrtnsseesttrrntessrttntrtsstttntrnnnnnertrnnnnnnsstnnnn ennenen ne 13 Figure 5 2 swarm bee LE module footprint 13 Figure 5 3 swarm bee LE module footprint and landing pattern top view 14 Page 4 Doc ID NA 14 0267 0005 1 2 2015 All Rights Reserved ana not ron Application Note TECHNOLOGIES AN0504 Tag Design with swarm bee LE Version 1 2 Author JDI 1 Introduction The swarm bee LE CSS radio module is a fully integrated wireless node The module works both in applications with collaborative location technology based on TOF ranging and fixed location technology based on TDOA time difference of arrival and supports concurrent communication This application note describes the necessary steps to create tag designs utilizing the swarm bee LE module It explains how to utilize nanotron s new swarm bee LE radio module to build smart tags with host controller and basic tags without host controller Circuit diagrams for both architectures are shown and could e
19. ser Guide V1 0 as of 27 10 2014 Doc ID NA 14 0267 0009 1 0 Page 16 Doc ID NA 14 0267 0005 1 2 2015 All Rights Reserved ana not ron Application Note TECHNOLOGIES AN0504 Tag Design with swarm bee LE Version 1 2 Author JDI End of Document 2015 All Rights Reserved Doc ID NA 14 0267 0005 1 2 Page 17 Application Note AN0504 Tag Design with swarm bee LE Version 1 2 Author JDI nanotron TECHNOLOGIES Document History 2014 09 30 JDI 2015 04 10 JDI 2015 11 02 JDI 1 0 1 1 1 2 Initial version Battery monitoring added power saving mode updated Design hints for chip antenna chapter 2 1 1 added Power modes added Typos corrected Page 18 Doc ID NA 14 0267 0005 1 2 2015 All Rights Reserved Application Note AN0504 Tag Design with swarm bee LE Version 1 2 Author JDI Life Support Policy These products are not designed for use in life support appliances devices or systems where malfunction of these products can reasonably be expected to result in personal injury Nanotron Technologies GmbH customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Nanotron Technologies GmbH for any damages resulting from such improper use or sale Electromagnetic Interference Compatibility Nearly every electronic device is susceptible to electromagnetic interference EMI if inadequately shielded designed or otherwise
20. tion method adopted Power consumption varies for different application scenarios 4 3 Battery Lifetime The battery lifetime of a stand alone tag can be calculated when power consumption is known and the battery capacity is given In the following a sample calculation is shown for typical location sequences 4 3 1 Collaborative Location Ranging swarm bee tags can be used for collaborative location as shown in Figure 4 1 where one moving tag ranges with one or more other moving or fixed tags in its neighbourhood Local anchors which have received ranging results forward them to the location server which calculates the accurate location of the tag A0 h D A0 Am Au Figure 4 1 collaborative location of swarm bee tags When a swarm bee tag only ranges to one other tag the energy consumption for a ranging cycle has been measured as about 1200 pAs when the board is working in in 80MHz If the ranging interval is 10 s the Page 10 Doc ID NA 14 0267 0005 1 2 2015 All Rights Reserved aana not ron Application Note TECHNOLOGIES AN0504 Tag Design with swarm bee LE Version 1 2 Author JDI battery capacity 1200 mAh and the battery efficiency 90 the approximate battery lifetime T can be calculated as follows 1200 MAh 90 Die 9000h 1200 pAs 10 s When a swarm bee tag ranges to more than one tags the energy consumption for a ranging cycle would be increased by about 300 As per tag If the other paramters are n
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