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Not eXactly C (NXC)

1. SetDisplayPopup 0 TEXTLINE 1 8 PopupMem Page 42 NXC Programmer s Guide 3 7 Loader Module The NXT loader module encompasses support for the NXT file system The NXT supports creating files opening existing files reading writing renaming and deleting files Files in the NXT file system must adhere to the 15 3 naming convention for a maximum filename length of 19 characters While multiple files can be opened simultaneously a maximum of 4 files can be open for writing at any given time When accessing files on the NXT errors can occur The NXC API defines several constants that define possible result codes They are listed in the following table Loader Result Codes Value LDR SUCCESS 0x0000 LDR INPROGRESS 0x0001 LDR_REQPIN 0x0002 LDR_NOMOREHANDLES 0x8100 LDR_NOSPACE 0x8200 LDR_NOMOREFILES 0x8300 LDR_EOFEXPECTED 0x8400 LDR_ENDOFFILE 0x8500 LDR_NOTLINEARFILE 0x8600 LDR_FILENOTFOUND 0x8700 LDR HANDLEALREADYCLOSED 0x8800 LDR NOLINEARSPACE 0x8900 LDR_UNDEFINEDERROR 0x8A00 LDR_FILEISBUSY 0x8B00 LDR_NOWRITEBUFFERS 0x8C00 LDR_APPENDNOTPOSSIBLE 0x8D00 LDR_FILEISFULL 0x8E00 LDR_FILEEXISTS 0x8F00 LDR_MODULENOTFOUND 0x9000 LDR_OUTOFBOUNDARY 0x9100 LDR_ILLEGALFILENAME 0x9200 LDR_ILLEGALHANDLE 0x9300 LDR_BTBUSY 0x9400 LDR_BTCONNECTFAIL 0x9500 LDR_BTTIMEOUT 0x9600 LDR_FILETX_TIM
2. NXC Programmer s Guide MotorActualSpeed output Value Get the actual speed value of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorActualSpeed OUT A MotorTachoCount output Value Get the tachometer count value of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorTachoCount OUT A MotorTachoLimit output Value Get the tachometer limit value of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorTachoLimit OUT A MotorRunState output Value Get the RunState value of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorRunState OUT A MotorTurnRatio output Value Get the turn ratio value of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorTurnRatio OUT A MotorRegulation output Value Get the regulation value of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorRegulation OUT A MotorOverload output Value Get the overload value of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorOverload OUT A MotorRegPValue
3. 1 Introduction NXC stands for Not eXactly C It is a simple language for programming the LEGO MINDSTORMS NXT product The NXT has a bytecode interpreter provided by LEGO which can be used to execute programs The NXC compiler translates a source program into NXT bytecodes which can then be executed on the target itself Although the preprocessor and control structures of NXC are very similar to C NXC is not a general purpose programming language there are many restrictions that stem from limitations of the NXT bytecode interpreter Logically NXC is defined as two separate pieces The NXC language describes the syntax to be used in writing programs The NXC Application Programming Interface API describes the system functions constants and macros that can be used by programs This API is defined in a special file known as a header file which should be included at the beginning of any NXC program By default this file is not automatically included when compiling a program This document describes both the NXC language and the NXC API In short it provides the information needed to write NXC programs Since there are different interfaces for NXC this document does not describe how to use any specific NXC implementation such as the command line compiler or Bricx Command Center Refer to the documentation provided with the NXC tool such as the NXC User Manual for information specific to that implementation For up to date informati
4. Output RotationCount value Table 17 IOMA Constants IOMA const n Value Get the specified IO Map Address value Valid IO Map Address constants are listed in Table 17 x IOMA InputIORawValue S3 SetIOMA const n val Function Set the specified IO Map Address to the value provided Valid IO Map Address constants are listed in Table 17 The value must be a specified via a constant a constant expression or a variable SetlOMA OutputlOPower OUT A x 3 4 Sound Module The NXT sound module encompasses all sound output features The NXT provides support for playing basic tones as well as two different types of files Sound files rso are like wav files They contain thousands of sound samples that digitally represent an analog waveform With sounds files the NXT can speak or play music or make just about any sound imaginable Melody files are like MIDI files They contain multiple tones with each tone being defined by a frequency and duration pair When played on the NXT a melody file sounds like a pure sine wave tone generator playing back a series of notes While not as fancy as sound files melody files are usually much smaller than sound files When a sound or a file is played on the NXT execution of the program does not wait for the previous playback to complete To play multiple tones or files sequentially it is necessary to wait for the previous tone or file playback to complete first This ca
5. val UIState val UIButton val VMRunState val BatteryState val SleepTimeout val SleepTimer val RechargeableBattery val OnBrickProgramPointer SetCommandFlags n SetUIState n SetUIButton n Page 48 NXC Programmer s Guide SetVMRunsState n SetBatteryState n SetSleepTimeout n SetSleepTimer n SetOnBrickProgramPointer n ForceOff n val StrToNum str val StrLen str val StrIndex str idx str NumToStr num str StrCat strl str2 strN str SubStr string idx len str StrReplace string idx strnew str Flatten num ByteArrayToStr a s StrToByteArray s a num ArrayLen a Arraylnit a val cnt ArraySubset aout asrc idx len ArrayBuildl aout src1 ArrayBuild2 aout src1 src2 ArrayBuild3 aout src1 src2 src3 Array Build4 aout src1 src2 src3 src4 Page 49 NXC Programmer s Guide GetUSBInputBuffer offset cnt data GetUSBOutputBuffer offset cnt data GetUSBPollBuffer offset cnt data val 2 UsbState SetUsbState n SetUSBInputBuffer offset cnt data SetUSBInputBufferInPtr n SetUSBInputBufferOutPtr n SetUSBOutputBuffer offset cnt data SetUSBOutputBufferInPtr n SetUSBOutputBufferOutPtr n SetUSBPollBuffer offset cnt data SetUSBPollBufferInPtr n SetUSBPollBufferOutPtr n SetUSBState n val USBInputBufferInPtr val USBInputBufferOutPtr val USBOutp
6. OnFwdReg OUT A 75 OUT REGMODE SPEED regulate speed OnFwdRegEx outputs pwr regmode const reset Function Run the specified outputs forward using the specified regulation mode Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values Valid regulation modes are listed in Table 15 The reset parameter controls whether any of the three position counters are reset It must be a constant Valid reset values are listed in Table 16 OnFwdRegEx OUT A 75 OUT REGMODE SPEED RESET NONE Page 29 NXC Programmer s Guide OnRevReg outputs pwr regmode Function Run the specified outputs in reverse using the specified regulation mode Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values Valid regulation modes are listed in Table 15 OnRevReg OUT A 75 OUT REGMODE SPEED regulate speed OnRevRegEx outputs pwr regmode const reset Function Run the specified outputs in reverse using the specified regulation mode Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values Valid regulation modes are listed in Table 15 The reset parameter controls whether any of the three position counters are reset It must be a constant Valid reset values are lis
7. STOP into State Play tone specified in Frequency for Duration milliseconds SOUND MODE TONE Read Table 20 Sound Mode Constants Miscellaneous sound constants from NBCCommon h are listed in the following table Misc Sound Constants Value Meaning FREQUENCY MIN 220 Minimum frequency in Hz FREQUENCY MAX 14080 Maximum frequency in Hz SAMPLERATE MIN 2000 Minimum sample rate supported by NXT SAMPLERATE DEFAULT 8000 Default sample rate SAMPLERATE MAX 16000 Maximum sample rate supported by NXT Table 21 Miscellaneous Sound Constants PlayTone frequency duration Function Play a single tone of the specified frequency and duration The frequency is in Hz The duration is in 1000ths of a second All parameters may be any valid expression PlayTone 440 500 Play A for one half second Page 36 NXC Programmer s Guide PlayToneEx frequency duration volume bLoop Function Play a single tone of the specified frequency duration and volume The frequency is in Hz The duration is in 1000ths of a second Volume should be a number from 0 silent to 4 loudest All parameters may be any valid expression PlayToneEx 440 500 2 false PlayFile filename Function Play the specified sound file rso or a melody file rmd The filename may be any valid string expression PlayFile startup rso PlayFileEx filename volume bLoop Function Play the specifie
8. SetSoundDuration 500 SoundSampleRate Value Return the current sound sample rate x SoundSampleRate SetSoundSampleRate n Function Set the current sound sample rate SetSoundSampleRate 4000 SoundVolume Value Return the current sound volume x SoundVolume SetSoundVolume n Function Set the current sound volume SetSoundVolume 3 Page 38 NXC Programmer s Guide StopSound Function Stop playback of the current tone or file StopSound 3 5 IOCtrl Module The NXT ioctrl module encompasses low level communication between the two processors that control the NXT The NXC API exposes two functions that are part of this module PowerDown Function Turn off the NXT immediately PowerDown RebootInFirmwareMode Function Reboot the NXT in SAMBA or firmware download mode This function is not likely to be used in a normal NXC program Reboot InFirmwareMode 3 6 Display module The NXT display module encompasses support for drawing to the NXT LCD The NXT supports drawing points lines rectangles and circles on the LCD It supports drawing graphic icon files on the screen as well as text and numbers The LCD screen has its origin 0 0 at the bottom left hand corner of the screen with the positive Y axis extending upward and the positive X axis extending toward the right The NXC API provides constants for use in the NumOut and TextOut functions which makes it possi
9. a constant e g S1 S2 S3 or S4 SetCustomSensorPercentFullScale S1 100 SetCustomSensorA ctiveStatus const p value Function Sets the custom sensor active status value of a sensor The port must be specified using a constant e g S1 S2 S3 or S4 SetCustomSensorActiveStatus S1 true Page 20 NXC Programmer s Guide SetSensorDigiPinsDirection const p value Function Sets the digital pins direction value of a sensor The port must be specified using a constant e g S1 S2 S3 or S4 SetSensorDigiPinsDirection Sl 1 SetSensorDigiPinsStatus const p value Function Sets the digital pins status value of a sensor The port must be specified using a constant e g S1 S2 S3 or 84 SetSensorDigiPinsStatus S1 false SetSensorDigiPinsOutputLevel const p value Function Sets the digital pins output level value of a sensor The port must be specified using a constant e g S1 S2 S3 or S4 SetSensorDigiPinsOutputLevel S1 100 3 1 2 Sensor Information There are a number of values that can be inspected for each sensor For all of these values the sensor must be specified by a constant port value e g 81 S2 S3 or S4 unless otherwise specified Sensor n Value Return the processed sensor reading for a sensor on port n where n is 0 1 2 or 3 or a sensor port name constant This is the same value that is returned by the sensor value names e g SENSOR 1 A variable whose
10. changes to the TachoLimit The value of this field is a relative distance from the current motor position at the moment when the UF UPDATE TACHO LIMIT flag is processed RunState ubyte Read Write 0 255 Use this field to specify the running state of an output Set the RunState to OUT RUNSTATE RUNNING to enable power to any output Use OUT RUNSTATE RAMPUP to enable automatic ramping to a new Power level greater than the current Power level Use OUT RUNSTATE RAMPDOWN to enable automatic ramping to a new Power level less than the current Power level Both the rampup and rampdown bits must be used in conjunction with appropriate TachoLimit and Power values In this case the firmware smoothly increases or decreases the actual power to the new Power level over the total number of degrees of rotation specified in TachoLimit TurnRatio sbyte Read Write 100 100 Use this field to specify a proportional turning ratio This field must be used in conjunction with other field values OutputMode must include OUT_MODE_MOTORON and OUT_MODE_REGULATED RegMode must be set to OUT REGMODE SYNC RunState must not be OUT RUNSTATE IDLE and Speed must be non zero There are only three valid combinations of left and right motors for use with TurnRatio OUT AB OUT BC and OUT AC In each of these three options the first motor listed is considered to be the left motor and the second motor is the right motor regardless of the
11. counters are reset It must be a constant Valid reset values are listed in Table 16 OnRevSyncEx OUT AB 75 100 RESET NONE spin left Page 30 NXC Programmer s Guide RotateMotor outputs pwr angle Function Run the specified outputs forward for the specified number of degrees Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values RotateMotor OUT A 75 45 forward 45 degrees RotateMotor OUT A 75 45 reverse 45 degrees RotateMotorPID outputs pwr angle p i d Function Run the specified outputs forward for the specified number of degrees Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values Also specify the proportional integral and derivative factors used by the firmware s PID motor control algorithm RotateMotorPID OUT A 75 45 20 40 100 RotateMotorEx outputs pwr angle turnpct sync Function Run the specified outputs forward for the specified number of degrees Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values If a non zero turn percent is specified then sync must be set to true or no turning will occur RotateMotorEx OUT AB 75 360 50 true RotateMotorExPID outputs pwr angle turnpct sync p i
12. d Function Run the specified outputs forward for the specified number of degrees Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values If a non zero turn percent is specified then sync must be set to true or no turning will occur Also specify the proportional integral and derivative factors used by the firmware s PID motor control algorithm RotateMotorExPID OUT AB 75 360 50 true 30 50 90 ResetTachoCount outputs Function Reset the tachometer count and tachometer limit goal for the specified outputs Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC Or variable containing one of these values ResetTachoCount OUT AB ResetBlockTachoCount outputs Function Reset the block relative position counter for the specified outputs Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values ResetBlockTachoCount OUT AB Page 31 NXC Programmer s Guide ResetRotationCount outputs Function Reset the program relative position counter for the specified outputs Outputs can be OUT_A OUT_B OUT_C OUT_AB OUT_AC OUT_BC OUT_ABC or a variable containing one of these values ResetRotationCount OUT AB ResetAllTachoCounts outputs Function Reset all three pos
13. for the line parameter I GetDisplayNormal 0 TEXTLINE 1 8 ScreenMem SetDisplayNormal x line count data Function Write count bytes to the normal display memory from the data array Start writing at the specified x line coordinate Each byte of data read from screen memory is a vertical strip of 8 bits at the desired location Each bit represents a single pixel on the LCD screen Use TEXT LINE1 through TEXT LINES for the line parameter I SetDisplayNormal 0 TEXTLINE 1 8 ScreenMem GetDisplayPopup x line count data Function Read count bytes from the popup display memory into the data array Start reading from the specified x line coordinate Each byte of data read from screen memory is a vertical strip of 8 bits at the desired location Each bit represents a single pixel on the LCD screen Use TEXT LINE1 through TEXT LINES for the line parameter GetDisplayPopup 0 TEXTLINE 1 8 PopupMem SetDisplayPopup x line count data Function Write count bytes to the popup display memory from the data array Start writing at the specified x line coordinate Each byte of data read from screen memory is a vertical strip of 8 bits at the desired location Each bit represents a single pixel on the LCD screen Use TEXT LINE1 through TEXT LINES for the line parameter
14. it directly to the NBC compiler backend The asm statement can often be used to optimize code so that it executes as fast as possible on the NXT firmware The following example shows an asm block containing variable declarations labels and basic NBC statements as well as comments asm jmp __1b100D5 dseg segment s10000 slong s10005 slong bGTTrue byte dseg ends mov s10000 0x0 mov s10005 s10000 mov s10000 0x1 cmp GT bGITrue s10005 s10000 set bGTTrue FALSE brtst EQ X 1b100D5 bGTTrue __1b100D5 A few NXC keywords have meaning only within an asm statement These keywords provide a means for returning string or scalar values from asm statements and for using temporary integer variables of byte word and long sizes ASM Keyword Meaning __RETURN__ Used to return a value other than RETVAL or STRRETVAL RETVAL Writing to this 4 byte value returns it to the calling program STRRETVAL Writing to this string value returns it to the calling program IMPBYTE Use this temporary variable to write and return single byte values TMPWORD Use this temporary variable to write and return 2 byte values _ TMPLONG Use this temporary variable to write and return 4 byte values Table 4 ASM Keywords Page 12 NXC Programmer s Guide The asm block statement and these special ASM keywords are used throughout the NXC API See the NXCDefs h h
15. just touch sensors This boolean conversion is normally based on preset thresholds for the raw value A low value less than 460 is a boolean value of 1 A high value greater than 562 is a boolean value of 0 This conversion can be modified a slope value between 0 and 31 may be added to a sensor s mode when calling Set SensorMode If the sensor s value changes more than the slope value during a certain time 3ms then the sensor s boolean state will change This allows the boolean state to reflect rapid changes in the raw value A rapid increase will result in a boolean value of 0 a rapid decrease is a boolean value of 1 Even when a sensor is configured for some other mode i e SENSOR MODE the boolean conversion will still be carried out P ERC ENT Each sensor has six fields that are used to define its state The field constants are described in the following table Sensor Field Constant Meaning Type The sensor type see Table 7 Page 18 NXC Programmer s Guide InputMode The sensor mode see Table 8 Raw Value NormalizedValue ScaledValue InvalidData Table 10 Sensor Field Constants SetSensor const port const configuration Function Set the type and mode of the given sensor to the specified configuration which must be a special constant containing both type and mode information The port must be specified using a constant e
16. output Value Get the proportional PID value of the specified output Output can be OUT_A OUT_B OUT C or a variable containing one of these values x MotorRegPValue OUT A Page 33 NXC Programmer s Guide MotorRegIValue output Value Get the integral PID value of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorRegIValue OUT A MotorRegDV alue output Value Get the derivative PID value of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorRegDValue OUT A MotorBlockTachoCount output Value Get the block relative position counter value of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorBlockTachoCount OUT A MotorRotationCount output Value Get the program relative position counter value of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorRotationCount OUT A MotorPwnFreq Value Get the current motor pulse width modulation frequency x MotorPwnFreq SetMotorPwnFreq val Function Set the current motor pulse width modulation frequency SetMotorPwnF req x 3 3 10 Map Addresses The NXT firmware provides a mechanism for reading and writing input sensor and output motor field values using low leve
17. physical configuration of the robot Negative TurnRatio values shift power toward the left motor while positive values shift power toward the right motor An absolute value of 50 usually results in one motor stopping An absolute value of 100 usually results in two motors turning in opposite directions at equal power RegMode ubyte Read Write 0 255 This field specifies the regulation mode to use with the specified port s It is ignored if the OUT MODE REGULATED bit is not set in the OutputMode field Unlike the OutputMode field RegMode is not a bitfield Only one RegMode value can be set at a time Valid RegMode values are listed in Table 15 Speed regulation means that the firmware tries to maintain a certain speed based on the Power setting The firmware adjusts the PWM duty cycle if the motor is affected by a physical load This adjustment is reflected by the value of the ActualSpeed property When using speed regulation do not set Power to its maximum value since the firmware cannot adjust to higher power levels in that situation Synchronization means the firmware tries to keep two motors in synch regardless of physical loads Use this mode to maintain a straight path for a mobile robot automatically Also use this mode with the TurnRatio property to provide Page 25 NXC Programmer s Guide proportional turning Set OUT REGMODE SYNC on at least two motor ports in order for sync
18. terminates macros but the newline may be escaped with the backslash 1 to allow multi line macros define foo x do bar x baz x while false The undef directive may be used to remove a macro s definition 2 5 3 Concatenation The directive works similar to the C preprocessor It is replaced by nothing which causes tokens on either side to be concatenated together Because it acts as a separator initially it can be used within macro functions to produce identifiers via combination with parameter values 2 5 4 Conditional Compilation Conditional compilation works similar to the C preprocessor The following preprocessor directives may be used ifdef symbol ifndef symbol else endif Page 16 NXC Programmer s Guide 3 NXC API The NXC API defines a set of constants functions values and macros that provide access to various capabilities of the NXT such as sensors outputs and communication The API consists of functions values and constants A function is something that can be called as a statement Typically it takes some action or configures some parameter Values represent some parameter or quantity and can be used in expressions Constants are symbolic names for values that have special meanings for the target Often a set of constants will be used in conjunction with a function 3 1 Input Module The NXT input module encompasses all sensor inputs There are four sensors which inter
19. x and y location using the specified radius Optionally clear the screen first depending on the boolean value of clear CircleOut 40 40 10 false LineOut x1 y1 x2 y2 clear Function Draw a line on the screen from x1 yl to x2 y2 Optionally clear the screen first depending on the boolean value of clear LineOut 40 40 10 10 false PointOut x y clear Function Draw a point on the screen at x y Optionally clear the screen first depending on the boolean value of clear PointOut 40 40 false RectOut x y width height clear Function Draw a rectangle on the screen at x y with the specified width and height Optionally clear the screen first depending on the boolean value of clear RectOut 40 40 30 10 false ResetScreen Function Restore the standard NXT running program screen ResetScreen ClearScreen Function Clear the NXT LCD to a blank screen ClearScreen Page 40 NXC Programmer s Guide 3 6 2 Low level functions Valid display flag values are listed in the following table Display Flags Constant Read Write Meaning DISPLAY ON Write Display is on DISPLAY REFRESH Write Enable refresh DISPLAY POPUP Write Use popup display memory DISPLAY REFRESH DISABLED Read Refresh is disabled DISPLAY BUSY Read Refresh is in progress Table 22 Display Flags Constants DisplayFlags Return the current display flags Valid flag valu
20. 32 bit unsigned long 32 bit signed mutex Special type used for exclusive code access string Array of byte struct User defined structure types arrays Arrays of any type Table 2 Variable Types Variables are declared using the keyword for the desired type followed by a comma separated list of variable names and terminated by a semicolon Optionally an initial value for each variable may be specified using an equals sign after the variable name Several examples appear below int x declare x bool y z declare y and z long a 1 b declare a and b initialize a to 1 Page 6 NXC Programmer s Guide Global variables are declared at the program scope outside of any code block Once declared they may be used within all tasks functions and subroutines Their scope begins at declaration and ends at the end of the program Local variables may be declared within tasks and functions Such variables are only accessible within the code block in which they are defined Specifically their scope begins with their declaration and ends at the end of their code block In the case of local variables a compound statement a group of statements bracketed by and is considered a block int x X4 x is global task main int y y is local to task main x y ok begin compound statement int z local declared yz ok y z error no longer in scope task fo
21. 9 3 6 1 High evel functions iria 39 3 6 2 LOW E Vel f nctlOns 1 oec tore iet hse Dee Er eise odo sn 41 3 7 Loader Module an hanas i ics AAA Ee e ee 43 3 8 Commi Module 35 55 aO DIN 46 3 9 General Beat fes cotes tet tre opas e Goes ies Put Pee y osa ee Gece goo 47 Pagei List of Tables Table t NXC AR O 3 Table 2 Variable TIPS iS o 6 Table 3 Operators iso ee ti ba ein 9 Table A SMR Gy Words fassen un A E E EE AA 12 Table 2 BXDIBSSIOHS a ii 14 Lal E tui E th ae 15 Table 7 Sensor Type Constants ann edet eoi ee i i E E OSE oed S SiS 18 Table 8 Sensor Mode Constants a Hei 18 Table 9 Sensor Configuration Constants aoi onset ote rex Ib IER M e Reels Ses 18 Table TO Sensor Ere dC ad 19 Table 11 Output Field Constants eee nenn hin 26 Table 12 Update blas Consta ais een be a ey o eo URN dT 27 Table 13 OuputModeEonsens ea 27 Table Rum State Constants ni ais 27 Tabl 15 RegM de Constants aaa 27 Table 16 Reset Constants sisi ER Eh 28 Table T7 TOMA OTS CARTES x iio So ty ys ns Sarti pede ted seu qe eeu tas a a E ETa Aie 35 Table T5 sou ndd 139 4 Ons Ea so o sestien eun aoe E E ERE 36 Table 19 Sound State Constants 45 nete ret tain tein genau 36 Table 20 Sound Mode Constants au aan 36 Table 21 Miscellaneous Sound Constant ei nntedigneaas 36 Table 22 Display Flags Consans an nel 41 Table 23 Loader Result Codes nalen e Bree tesi oda ivo shed as oce tyi i pae 43 Page ii NXC Programmer s Guide
22. EOUT 0x9700 LDR_FILETX_DSTEXISTS 0x9800 LDR_FILETX_SRCMISSING 0x9900 LDR_FILETX_STREAMERROR 0x9A00 LDR FILETX CLOSEERROR 0x9B00 Table 23 Loader Result Codes FreeMemory Value Get the number of bytes of flash memory that are available for use x FreeMemory Page 43 NXC Programmer s Guide CreateFile filename size out handle Value Create a new file with the specified filename and size and open it for writing The file handle is returned in the last parameter which must be a variable The loader result code is returned as the value of the function call The filename and size parameters must be constants constant expressions or variables result CreateFile data txt 1024 handle OpenFileA ppend filename out size out handle Value Open an existing file with the specified filename for writing The file size is returned in the second parameter which must be a variable The file handle is returned in the last parameter which must be a variable The loader result code is returned as the value of the function call The filename parameter must be a constant or a variable result OpenFileAppend data txt fsize handle OpenFileRead filename out size out handle Value Open an existing file with the specified filename for reading The file size is returned in the second parameter which must be a variable The file handle is returned in the last parameter which must be a variable The lo
23. Not eXactly C NXC Programmer s Guide Version 1 0 1 b25 by John Hansen Contents 1 2 ML A o E IS 1 The NAC EA o 2 2 1 kexical R les ca ue omne lao ici 2 2 1 1 Comments tral ais 2 212 Whilesp acesen nasse 2 2 1 3 Numerical CONSA S E A R A R A a 3 2 1 4 Identifiers and Keywords eret sas iite 3 2 4 Program SUUCLUITG aii oen TN 3 2 2 1 JE cm OO O 3 2 2 2 PUT CU OMNS u sie 4 2 2 3 Mariables i a RN RE EN ees 6 2 2 4 jas Se 7 2 23 Aay A Lue NE 7 2 3 Statements s cii e b IRGEND GNU ERIT a 8 2 3 1 Variable Declaration it 8 2 3 2 vcnit Q 9 2 3 3 Control StFUCLUEGS nos Se EE 9 2 3 4 The AS Statement it eee ederet ee eed Riee 12 2 3 5 Other Statements canada ipods 13 DA ERDIESSIONS tii 13 2 4 1 Conditions ae 15 J Ne Pre Broccoli pna eere EE 15 2 5 1 incl der mussten et res t eoi ot ted tei ete ins 15 2532 FON a er 16 2 5 3 Concatenation useesessssssssssnseesensnnssnsnnnsnnnnnensnnnsnsnnnsnnnnnsnnsensssnsnnennennenn 16 2 5 4 Conditional COMPA sense 16 NXC A rer 17 3 1 put Module ea eost etudes scias E ee o de des 17 3 1 1 Types and Modes A Se 17 3 1 2 Sensor Information lee a ados 21 3 2 O near 23 3 2 1 Convenience Calls 3 445 eerte dead fot ette ewes eicit 27 3 2 2 Primittve CallS a tt Et M E 32 33 JO Map Addiesses nase ste be 34 3 4 Sound Module iei ID CIR SRI erue 35 3 5 IOCH MgSd le releases dat sei tures 39 O Edd a a Deb 3
24. O SENSOR no sensor configured SENSOR TYPE TOUCH IN TYPE SWITCH NXT or RCX touch sensor SENSOR TYPE TEMPERATURE IN TYPE TEMPERATURE RCX temperature sensor SENSOR TYPE LIGHT IN TYPE REFLECTION RCX light sensor SENSOR TYPE ROTATION IN TYPE ANGLE RCX rotation sensor SENSOR TYPE LIGHT ACTIVE IN TYPE LIGHT ACTIVE NXT light sensor with light SENSOR TYPE LIGHT INACTIVE IN TYPE LIGHT INACTIVE NXT light sensor without light SENSOR TYPE SOUND DB IN TYPE SOUND DB NXT sound sensor with dB scaling SENSOR TYPE SOUND DBA IN TYPE SOUND DBA NXT sound sensor with dBA scaling SENSOR TYPE CUSTOM IN TYPE CUSTOM Custom sensor unused Page 17 NXC Programmer s Guide SENSOR TYPE LOWSPEED IN TYPE LOWSPEED I2C digital sensor SENSOR TYPE LOWSPEED 9V IN TYPE LOWSPEED 9V I2C digital sensor 9V power SENSOR TYPE HIGHSPEED IN TYPE HISPEED Highspeed sensor unused Table 7 Sensor Type Constants The NXT allows a sensor to be configured in different modes The sensor mode determines how a sensor s raw value is processed Some modes only make sense for for example SENSOR MODE ROTATION is useful only with rotation sensors Call SetSensorMode to set the sensor mode The possible modes are shown below Use either the Sensor Mode constant or the NBC Sensor Mode constant certain types of sensors Sensor Mode NBC Sensor Mode M
25. Sign of operand n a sign x Post increment Post left variables only x decrement Unary minus right X Bitwise negation unary right constant only 123 Logical negation right Ix 1 Multiplication division left x y modulo Addition subtraction left x y lt lt 22 Left and right shift left X 4 Ey Ay relational operators left x lt y ES SS equal to not equal to left x amp Bitwise AND left x amp y Bitwise XOR left x y Bitwise OR left xly amp amp Logical AND left X amp amp y Il Logical OR left x Il y PE conditional value n a x 1 y Zz Table 5 Expressions Where needed parentheses may be used to change the order of evaluation set x to 14 set y to 20 x 24 3 4 y 2 3 4 Page 14 NXC Programmer s Guide 2 4 1 Conditions Comparing two expressions forms a condition There are also two constant conditions true and false that always evaluate to true or false respectively A condition may be negated with the negation operator or two conditions combined with the AND and OR operators The table below summarizes the different types of conditions Condition Meaning true always true false always false expr true if expr is not equal to O exprl expr2 true if exprl equals expr2 exprl expr2 true if exprl is not equal to expr2 exprl expr2 true if one exprl is less than expr2
26. T ABC or a variable containing one of these values OnFwd OUT A 75 OnFwdEx outputs pwr const reset Function Set outputs to forward direction and turn them on Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values The reset parameter controls whether any of the three position counters are reset It must be a constant Valid reset values are listed in Table 16 OnFwdEx OUT A 75 RESET NONE OnRev outputs pwr Function Set outputs to reverse direction and turn them on Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values OnRev OUT A 75 OnRevEx outputs pwr const reset Function Set outputs to reverse direction and turn them on Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values The reset parameter controls whether any of the three position counters are reset It must be a constant Valid reset values are listed in Table 16 OnRevEx OUT A 75 RESET NONE OnFwdReg outputs pwr regmode Function Run the specified outputs forward using the specified regulation mode Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values Valid regulation modes are listed in Table 15
27. acholimit Page 54
28. ader result code is returned as the value of the function call The filename parameter must be a constant or a variable result OpenFileRead data txt fsize handle CloseFile handle Value Close the file associated with the specified file handle The loader result code is returned as the value of the function call The handle parameter must be a constant or a variable result CloseFile handle ResolveHandle filename out handle out bWriteable Value Resolve a file handle from the specified filename The file handle is returned in the second parameter which must be a variable A boolean value indicating whether the handle can be used to write to the file or not is returned in the last parameter which must be a variable The loader result code is returned as the value of the function call The filename parameter must be a constant or a variable result ResolveHandle data txt handle bCanWrite RenameFile oldfilename newfilename Value Rename a file from the old filename to the new filename The loader result code is returned as the value of the function call The filename parameters must be constants or variables result RenameFile data txt mydata txt Page 44 NXC Programmer s Guide DeleteFile filename Value Delete the specified file The loader result code is returned as the value of the function call The filename parameter must be a constant or a variable result D
29. alternative is executed if the condition is false The two syntaxes for an if statement is shown below Page 9 NXC Programmer s Guide if condition consequence if condition consequence else alternative Note that the condition is enclosed in parentheses Examples are shown below Note how a compound statement is used in the last example to allow two statements to be executed as the consequence of the condition if x 1 y 2 if x 1 y 3 else y 4 if x 1 y 1 z 2 The while statement is used to construct a conditional loop The condition is evaluated and if true the body of the loop is executed then the condition is tested again This process continues until the condition becomes false or a break statement is executed The syntax for a while loop appears below while condition body It is very common to use a compound statement as the body of a loop while x lt 10 x x 1 y 2 K A variant of the while loop is the do while loop Its syntax is do body while condition The difference between a while loop and a do while loop is that the do whi le loop always executes the body at least once whereas the while loop may not execute it at all Another kind of loop is the or loop for stmt1 condition stmt2 body A for loop always executes stmtl then it repeatedly checks the condition and while it remains true executes the body followed by stmt2 The or loop
30. alue of the expression to the variable The other operators modify the variable s value in some other way as shown in the table below Operator Action Set variable to expression Add expression to variable Subtract expression from variable Multiple variable by expression Divide variable by expression Set variable to remainder after dividing by expression amp Bitwise AND expression into variable Bitwise OR expression into variable ds Bitwise exclusive OR into variable l Set variable to absolute value of expression Set variable to sign 1 1 0 of expression gt gt Right shift variable by expression lt lt Left shift variable by expression Table 3 Operators Some examples x 2 set x to 2 y 7 set y to 7 x y x is 9 y is still 7 2 3 3 Control Structures The simplest control structure is a compound statement This is a list of statements enclosed within curly braces and x 1 y 2 Although this may not seem very significant it plays a crucial role in building more complicated control structures Many control structures expect a single statement as their body By using a compound statement the same control structure can be used to control multiple statements The if statement evaluates a condition If the condition is true it executes one statement the consequence An optional second statement the
31. ble to specify LCD line numbers between 1 and 8 with line 1 being at the top of the screen and line 8 being at the bottom of the screen These constants LCD LINE LCD LINE2 LCD LINE3 LCD LINEA LCD LINE5 LCD LINE6 LCD LINE7 LCD LINES should be used as the Y coordinate in NumOut and TextOut calls Values of Y other than these constants will be adjusted so that text and numbers are on one of 8 fixed line positions 3 6 1 High level functions NumOut x y clear value Function Draw a numeric value on the screen at the specified x and y location Optionally clear the screen first depending on the boolean value of clear NumOut 0 LCD LINE1 true x Page 39 NXC Programmer s Guide TextOut x y clear msg Function Draw a text value on the screen at the specified x and y location Optionally clear the screen first depending on the boolean value of clear TextOut 0 LCD LINE3 false Hello World GraphicOut x y filename clear Function Draw the specified graphic icon file on the screen at the specified x and y location Optionally clear the screen first depending on the boolean value of clear If the file cannot be found then nothing will be drawn and no errors will be reported GraphicOut 40 40 image ric false CircleOut x y radius clear Function Draw a circle on the screen with its center at the specified
32. case 2 case 3 do something else when x is 2 or 3 break default do this when x is not 1 2 or 3 break NXC also supports using string types in the switch expression and constant strings in case labels The goto statement forces a program to jump to the specified location Statements in a program can be labeled by preceding them with an identifier and a colon A goto statement then specifies the label that the program should jump to For example this is how an infinite loop that increments a variable could be implemented using goto my_loop xtt goto my loop The goto statement should be used sparingly and cautiously In almost every case control structures such as if while and switch make a program much more readable and maintainable than using got o NXC also defines the until macro which provides a convenient alternative to the while loop The actual definition of until is Page 11 NXC Programmer s Guide define until c while c In other words until will continue looping until the condition becomes true It is most often used in conjunction with an empty body statement until SENSOR 1 1 wait for sensor to be pressed 2 3 4 The asm Statement The asm statement is used to define many of the NXC API calls The syntax of the statement is asm one or more lines of assembly language The statement simply emits the body of the statement as NeXT Byte Codes NBC code and passes
33. ces tabs and newlines is used to separate tokens and to make programs more readable As long as the tokens are distinguishable adding or subtracting whitespace has no effect on the meaning of a program For example the following lines of code both have the same meaning x 2 X 2 Some of the C operators consist of multiple characters In order to preserve these tokens whitespace must not be inserted within them In the example below the first line Page 2 NXC Programmer s Guide uses a right shift operator gt gt but in the second line the added space causes the gt symbols to be interpreted as two separate tokens and thus generate an error x 1 gt gt 4 set x to 1 right shifted by 4 bits x 1 gt gt 4 error 2 1 3 Numerical Constants Numerical constants may be written in either decimal or hexadecimal form Decimal constants consist of one or more decimal digits Hexadecimal constants start with 0x or 0X followed by one or more hexadecimal digits x 10 set x to 10 x 0x10 set x to 16 10 hex 2 1 4 Identifiers and Keywords Identifiers are used for variable task function and subroutine names The first character of an identifier must be an upper or lower case letter or the underscore _ Remaining characters may be letters numbers and an underscore A number of potential identifiers are reserved for use in the NXC language itself These reserved words are call keywords a
34. ctor byte fooArray Arraylnit myVector 0 10 10 zeros in myVector Arraylnit myArray myVector 10 10 vectors myArray ArrayInit fooArray myArray 2 2 myArrays in fooArray myVector myArray 1 okay as of b25 fooArray 1 myArray okay as of b25 myVector 4 34 myArray 1 myVector okay as of b25 int ax ayll ArrayBuild2 ax 5 6 ArrayBuild4 ay 2 10 6 43 int axlen ArrayLen ax ArraySubset ax ay 1 2 ax 10 6 if ax ay array comparisons supported as of b25 2 3 Statements The body of a code block task or function is composed of statements Statements are terminated with a semi colon 2 3 1 Variable Declaration Variable declaration as described in the previous section is one type of statement It declares a local variable with optional initialization for use within the code block The syntax for a variable declaration is int variables where variables is a comma separated list of names with optional initial value name expression Page 8 NXC Programmer s Guide Arrays of variables may also be declared int array initializer for global one dimension arrays 2 3 2 Assignment Once declared variables may be assigned the value of an expression variable assign operator expression There are nine different assignment operators The most basic operator simply assigns the v
35. d the NXC API provides predefined combinations of outputs OUT AI B OUT AC OUT BC and OUT ABC Manually combining outputs involves creating an array and adding two or more of the three individual output constants to the array Power levels can range 0 lowest to 100 highest Negative power levels reverse the direction of rotation 1 e forward at a power level of 100 actually means reverse at a power level of 100 The outputs each have several fields that define the current state of the output port These fields are defined in the table below Field Constant Type Access Range Meaning UpdateFlags ubyte Read Write 0 255 This field can include any combination of the flag bits described in Table 12 Use UF UPDATE MODE UF UPDATE SPEED UF UPDATE TACHO LIMIT and UF UPDATE PID VALUES along with other fields to commit changes to the state of outputs Set the appropriate flags after setting one or more of the output fields in order for the changes to actually go into affect OutputMode ubyte Read Write 0 255 This is a bitfield that can include any of the values listed in Table 13 The OUT MODE MOTORON bit must be set in order for power to be applied to the motors Add OUT MODE BRAKE to enable electronic braking Braking means that the output voltage is not allowed to float between active PWM pulses It improves the accuracy of motor output but uses more ba
36. d sound file rso or a melody file rmd The filename may be any valid string expression Volume should be a number from 0 silent to 4 loudest bLoop is a boolean value indicating whether to repeatedly play the file m PlayFileEx startup rso 3 true SoundFlags Value Return the current sound flags Valid sound flags values are listed in Table 18 x SoundFlags SetSoundFlags n Function Set the current sound flags Valid sound flags values are listed in Table 18 SetSoundFlags SOUND FLAGS UPDATE SoundState Value Return the current sound state Valid sound state values are listed in Table 19 x SoundState SetSoundState n Function Set the current sound state Valid sound state values are listed in Table 19 SetSoundState SOUND STATE STOP SoundMode Value Return the current sound mode Valid sound mode values are listed in Table 20 x SoundMode Page 37 NXC Programmer s Guide SetSoundMode n Function Set the current sound mode Valid sound mode values are listed in Table 20 SetSoundMode SOUND MODE ONCE SoundFrequency Value Return the current sound frequency x SoundFrequency SetSoundFrequency n Function Set the current sound frequency SetSoundFrequency 440 SoundDuration Value Return the current sound duration x SoundDuration SetSoundDuration n Function Set the current sound duration
37. eader file for several examples of how they can be put to use To keep the main NXC code as C like as possible and for the sake of better readability NXC asm block statements can be wrapped in preprocessor macros and placed in custom header files which are included using include The following example demonstrates using macro wrappers around asm block statements define SetMotorSpeed port cc thresh fast slow A asm set theSpeed fast brcmp cc EndIfOut I set theSpeed slow SV thresh _ EndIfOut I OnFwd port theSpeed Incl N 2 3 5 Other Statements A function call is a statement of the form name arguments The arguments list is a comma separated list of expressions The number and type of arguments supplied must match the definition of the function itself Tasks may be started with the start statement start task name Within loops such as a while loop the break statement can be used to exit the loop and the continue statement can be used to skip to the top of the next iteration of the loop The break statement can also be used to exit a switch statement break continue It is possible to cause a function to return before it reaches the end of its code using the return statement with an optional return value return value Most expressions are not legal statements One notable exception is expressions involving the increment or decreme
38. eaning SENSOR MODE RAW IN MODE RAW raw value from 0 to 1023 SENSOR MODE BOOL IN MODE BOOLEAN boolean value 0 or 1 SENSOR MODE EDGE IN MODE TRANSITIONCNT counts number of boolean transitions SENSOR MODE PULSE IN MODE PERIODCOUNTER counts number of boolean periods SENSOR MODE PERCENT IN MODE PCTFULLSCALE value from 0 to 100 SENSOR MODE FAHRENHEIT IN MODE FAHRENHEIT degrees F SENSOR MODE CELSIUS IN MODE CELSIUS degrees C SENSOR MODE ROTATION IN MODE ANGLESTEP rotation 16 ticks per revolution Table 8 Sensor Mode Constants When using the NXT it is common to set both the type and mode at the same time The SetSensor function makes this process a little easier by providing a single function to call and a set of standard type mode combinations Sensor Configuration Type Mode SENSOR TOUCH SENSOR TYPE TOUCH SENSOR MODE BOOL SENSOR LIGHT SENSOR TYPE LIGHT SENSOR MODE PERCENT SENSOR ROTATION SENSOR TYPE ROTATION SENSOR MODE ROTATION SENSOR CELSIUS SENSOR TYPE TEMPERATURE SENSOR MODE CELSIUS SENSOR FAHRENHEIT SENSOR TYPE TEMPERATURE SENSOR MODE FAHRENHEIT SENSOR PULSE SENSOR TYPE TOUCH SENSOR MODE PULSE SENSOR EDGE SENSOR TYPE TOUCH SENSOR MODE EDGE Table 9 Sensor Configuration Constants The NXT provides a boolean conversion for all sensors not
39. eleteFile data txt Read handle out value Value Read a numeric value from the file associated with the specified handle The loader result code is returned as the value of the function call The handle parameter must be a variable The value parameter must be a variable The type of the value parameter determines the number of bytes of data read result Read handle value ReadLn handle out value Value Read a numeric value from the file associated with the specified handle The loader result code is returned as the value of the function call The handle parameter must be a variable The value parameter must be a variable The type of the value parameter determines the number of bytes of data read The ReadLn function reads two additional bytes from the file which it assumes are a carriage return and line feed pair result ReadLn handle value ReadBytes handle in out length out buf Value Read the specified number of bytes from the file associated with the specified handle The loader result code is returned as the value of the function call The handle parameter must be a variable The length parameter must be a variable The buf parameter must be an array or a string variable The actual number of bytes read is returned in the length parameter result ReadBytes handle len buffer Write handle value Value Write a numeric value to the file associated with the specified handle The loader result code i
40. es are listed in Table 22 x DisplayFlags SetDisplayFlags n Set the current display flags Valid flag values are listed in Table 22 SetDisplayFlags x DisplayEraseMask Return the current display erase mask x DisplayEraseMask SetDisplayEraseMask n Set the current display erase mask SetDisplayEraseMask x Display UpdateMask Return the current display update mask x DisplayUpdateMask SetDisplayUpdateMask n Set the current display update mask SetDisplayUpdateMask x DisplayDisplay Return the current display memory address x DisplayDisplay Value Function Value Function Value Function Value Page 41 NXC Programmer s Guide SetDisplayDisplay n Function Set the current display memory address SetDisplayDisplay x DisplayTextLinesCenterFlags Value Return the current display text lines center flags x DisplayTextLinesCenterFlags SetDisplayTextLinesCenterFlags n Function Set the current display text lines center flags SetDisplayTextLinesCenterFlags x GetDisplayNormal x line count data Function Read count bytes from the normal display memory into the data array Start reading from the specified x line coordinate Each byte of data read from screen memory is a vertical strip of 8 bits at the desired location Each bit represents a single pixel on the LCD screen Use TEXT LINE1 through TEXT LINES
41. exprl lt expr2 true if exprl is less than or equal to expr2 exprl gt expr2 true if exprl is greater than expr2 exprl gt expr2 true if exprl is greater than or equal to expr2 condition logical negation of a condition true if condition is false condl amp amp cond2 logical AND of two conditions true if and only if both conditions are true condl cond2 logical OR of two conditions true if and only if at least one of the conditions are true Table 6 Conditions 2 5 The Preprocessor The preprocessor implements the following directives include define ifdef tifndef fendif fundef line fpragma Its implementation is fairly close to a standard C preprocessor so most things that work in a generic C preprocessor should have the expected effect in NXC Significant deviations are listed below 2 5 1 include The include command works as expected with the caveat that the filename must be enclosed in double quotes There is no notion of a system include path so enclosing a filename in angle brackets is forbidden ftinclude foo h ok Hinclude lt foo h gt error NXC programs usually begin with include NXCDefs h This standard header file includes many important constants and macros which form the core NXC API Page 15 NXC Programmer s Guide 2 5 2 define The define command is used for simple macro substitution Redefinition of a macro is an error The end of the line normally
42. f time in 1000ths of a second The time argument may be an expression or a constant Wait 1000 wait 1 second Wait Random 1000 wait random time up to 1 second Stop bvalue Function Stop the running program if bvalue is true This will halt the program completely so any code following this command will be ignored Stop x 24 stop the program if x 24 Random n Value Return an unsigned 16 bit random number between 0 and n exclusive N can be a constant or a variable x Random 10 Random Value Return a signed 16 bit random number x Random BatteryLevel Value Return the battery level in millivolts x BatteryLevel Acquire mutex Release mutex Precedes task1 task2 taskn Follows task1 task2 taskn ExitTo taskname val ButtonCount btn reset val ButtonPressed btn reset ReadButtonEx btn reset pressed count Page 47 NXC Programmer s Guide val ButtonPressCount b val ButtonLongPressCount b val ButtonShortReleaseCount b val ButtonLongReleaseCount b val ButtonReleaseCount b val ButtonState b SetButtonPressCount b n SetButtonLongPressCount b n SetButtonShortReleaseCount b n SetButtonLongReleaseCount b n SetButtonReleaseCount b n SetButtonState b n val FirstTick val CurrentTick ResetSleepTimer val Volume SetVolume n val CommandFlags
43. g S1 S2 S3 or S4 SetSensor S1 SENSOR TOUCH SetSensorType const port const type Function Set a sensor s type which must be one of the predefined sensor type constants The port must be specified using a constant e g S1 S2 S3 or SA SetSensorType Sl SENSOR TYPE TOUCH SetSensorMode const port const mode Function Set a sensor s mode which should be one of the predefined sensor mode constants A slope parameter for boolean conversion if desired may be added to the mode The port must be specified using a constant e g S1 S2 S3 or SA SetSensorMode S1 SENSOR MODE RAW raw mode SetSensorMode S1 SENSOR MODE RAW 10 slope 10 SetSensorLight const port Function Configure the sensor on the specified port as a light sensor active The port must be specified using a constant e g S1 S2 S3 or S4 SetSensorLight S1 SetSensorSound const port Function Configure the sensor on the specified port as a sound sensor dB scaling The port must be specified using a constant e g S1 S2 S3 or S4 SetSensorSound 1 SetSensorTouch const port Function Configure the sensor on the specified port as a touch sensor The port must be specified using a constant e g S1 S2 S3 or S4 SetSensorSound 1 Page 19 NXC Programmer s Guide SetSensorLowspeed const port Function Configure the sensor on the specified port as an I2C digital
44. he function oo attempts to set the value of its argument to 2 This is perfectly legal but since oo is working on a copy of the original argument the variable y from main task remains unchanged Page 4 NXC Programmer s Guide void foo int x x 2 task main int y 1 y is now equal to 1 foo y y is still equal to 1 The second type of argument const arg type is also passed by value but with the restriction that only constant values e g numbers may be used This is rather important since there are a number of NXT functions that only work with constant arguments void foo const int x PlaySound x ok x 1 error cannot modify argument task main foo 2 ok foo 4 5 ok expression is still constant foo x error x is not a constant The third type arg type s passes arguments by reference rather than by value This allows the callee to modify the value and have those changes visible in the caller However only variables may be used when calling a function using arg type amp arguments void foo int amp x x 2 task main int y 1 y is equal to 1 foo y y is now equal to 2 foo 2 error only variables allowed The fourth type const arg_type amp is rather unusual It is also passed by reference but with the restriction that the callee is not allowed to modify the value Because of t
45. his restriction the compiler is able to pass anything not just variables to functions using this type of argument In general this is the most efficient way to pass arguments in NXC Functions must be invoked with the correct number and type of arguments The example below shows several different legal and illegal calls to function oo Page 5 NXC Programmer s Guide void foo int bar const int baz do something here task main int x declare variable x foo 1 2 ok foo x 2 ok foo 2 x error 2nd argument not constant foo 2 error wrong number of arguments NXC functions may optionally be marked as inline functions This means that each call to a function will result in another copy of the function s code being included in the program Unless used judiciously inline functions can lead to excessive code size If a function is not marked as inline then an actual NXT subroutine is created and the call to the function in NXC code will result in a subroutine call to the NXT subroutine The total number of non inline functions aka subroutines and tasks must not exceed 256 2 2 3 Variables All variables in NXC are of the following types Type Name Information bool 8 bit unsigned byte unsigned char 8 bit unsigned char 8 bit signed unsigned int 16 bit unsigned short int 16 bit signed unsigned long
46. hronization to function Setting OUT REGMODE SYNC on all three motor ports will result in only the first two OUT A and OUT B being synchronized Overload ubyte Read 0 1 This field will have a value of 1 true if the firmware speed regulation cannot overcome a physical load on the motor In other words the motor is turning more slowly than expected If the motor speed can be maintained in spite of loading then this field value is zero false In order to use this field the motor must have a non idle RunState an OutputMode which includes OUT_MODE_MOTORON and OUT_MODE_REGULATED and its RegMode must be set to OUT REGMODE SPEED RegPValue ubyte Read Write 0 255 This field specifies the proportional term used in the internal proportional integral derivative PID control algorithm Set UF_UPDATE_PID_VALUES to commit changes to RegPValue RegI Value and RegDValue simultaneously RegIValue ubyte Read Write 0 255 This field specifies the integral term used in the internal proportional integral derivative PID control algorithm Set UF_UPDATE_PID_VALUES to commit changes to RegPValue RegI Value and RegDValue simultaneously RegDValue ubyte Read Write 0 255 This field specifies the derivative term used in the internal proportional integral derivative PID control algorithm Set UF_UPDATE_PID_VALUES to commit changes to RegPValue RegI Value and RegDValue simultaneo
47. ing all tasks using the Stop function or by a task stopping on its own via the ExitTo function or by task execution simply reaching the end of the task 2 2 2 Functions It is often helpful to group a set of statements together into a single function which can then be called as needed NXC supports functions with arguments and return values Functions are defined using the following syntax inline return_type name argument_list body of the function The return type should be the type of data returned In the C programming language functions are specified with the type of data they return Functions that do not return data are specified to return void The argument list may be empty or may contain one or more argument definitions An argument is defined by its type followed by its name Commas separate multiple arguments All values are represented as bool char byte int short long unsigned int unsigned long strings struct types or arrays of any type NXC also supports passing argument types by value by constant value by reference and by constant reference When arguments are passed by value from the calling function to the callee the compiler must allocate a temporary variable to hold the argument There are no restrictions on the type of value that may be used However since the function is working with a copy of the actual argument the caller will not see any changes it makes to the value In the example below t
48. ion call The handle parameter must be a variable The count parameter must be a variable The str parameter must be a string variable or string constant This function also writes a carriage return and a line feed to the file following the string data The total number of bytes written is returned in the count parameter result WriteLnString handle testing count WriteBytes handle data out count Value Write the contents of the data array to the file associated with the specified handle The loader result code is returned as the value of the function call The handle parameter must be a variable The count parameter must be a variable The data parameter must be an array The actual number of bytes written is returned in the count parameter result WriteBytes handle buffer count WriteBytesEx handle in out length buf Value Write the specified number of bytes to the file associated with the specified handle The loader result code is returned as the value of the function call The handle parameter must be a variable The length parameter must be a variable The buf parameter must be an array or a string variable or string constant The actual number of bytes written is returned in the length parameter result WriteBytesEx handle len buffer 3 8 Comm Module TBD Page 46 NXC Programmer s Guide 3 9 General Features Wait time Function Make a task sleep for specified amount o
49. is equivalent to stmtl while condition body stmt2 The repeat statement executes a loop a specified number of times repeat expression body The expression determines how many times the body will be executed Note It is only evaluated a single time and then the body is repeated that number of times This is different from both the while and do while loops which evaluate their condition each time through the loop Page 10 NXC Programmer s Guide A switch statement can be used to execute one of several different blocks of code depending on the value of an expression One or more case labels precede each block of code Each case must be a constant and unique within the switch statement The switch statement evaluates the expression then looks for a matching case label It will then execute any statements following the matching case until either a break statement or the end of the switch is reached A single default label may also be used it will match any value not already appearing in a case label Technically a switch statement has the following syntax switch expression body The case and default labels are not statements in themselves they are abels that precede statements Multiple labels can precede the same statement These labels have the following syntax case constant expression default A typical switch statement might look like this switch x case 1 do something when X is 1 break
50. ith braking Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values The reset parameter controls whether any of the three position counters are reset It must be a constant Valid reset values are listed in Table 16 OffEx OUT A RESET NONE turn off output A Coast outputs Function Turn off the specified outputs making them coast to a stop Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values Coast OUT A coast output A CoastEx outputs const reset Function Turn off the specified outputs making them coast to a stop Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values The reset parameter controls whether any of the three position counters are reset It must be a constant Valid reset values are listed in Table 16 CoastEx OUT A RESET NONE coast output A Float outputs Function Make outputs float Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values Float is an alias for Coast Float OUT A float output A Page 28 NXC Programmer s Guide OnFwd outputs pwr Function Set outputs to forward direction and turn them on Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OU
51. ition counters and reset the current tachometer limit goal for the specified outputs Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values ResetAllTachoCounts OUT AB 3 2 2 Primitive Calls SetOutput outputs const field1 vall const fieldN valN Function Set the specified field of the outputs to the value provided Outputs can be OUT_A OUT_B OUT_C OUT_AB OUT_AC OUT_BC OUT_ABC or a variable containing one of these values The field must be a valid output field constant This function takes a variable number of field value pairs SetOutput OUT AB TachoLimit 720 set tacho limit The output field constants are described in Table 11 GetOutput output const field Value Get the value of the specified field for the specified output Output can be OUT A OUT B OUT_C or a variable containing one of these values The field must be a valid output field constant x GetOutput OUT A TachoLimit The output field constants are described in Table 11 MotorMode output Value Get the mode of the specified output Output can be OUT A OUT B OUT C ora variable containing one of these values x MotorMode OUT A MotorPower output Value Get the power level of the specified output Output can be OUT A OUT B OUT C or a variable containing one of these values x MotorPower OUT A Page 32
52. its changes to the Power output property UF UPDATE TACHO LIMIT Commits changes to the TachoLimit output property UF UPDATE RESET COUNT Resets all rotation counters cancels the current goal and resets the rotation error correction system UF UPDATE PID VALUES Commits changes to the PID motor regulation properties UF UPDATE RESET BLOCK COUNT Resets the block relative rotation counter UF UPDATE RESET ROTATION COUNT Resets the program relative rotation counter Table 12 UpdateFlag Constants Valid OutputMode values are described in the following table OutputMode Constants Value Meaning OUT MODE COAST 0x00 No power and no braking so motors rotate freely OUT MODE MOTORON 0x01 Enables PWM power to the outputs given the Power setting OUT MODE BRAKE 0x02 Uses electronic braking to outputs OUT MODE REGULATED 0x04 Enables active power regulation using the RegMode value OUT MODE REGMETHOD 0xf0 Table 13 OutputMode Constants Valid RunState values are described in the following table RunState Constants Value Meaning OUT_RUNSTATE_IDLE 0x00 Disable all power to motors OUT_RUNSTATE_RAMPUP 0x10 Enable ramping up from a current Power to a new higher Power over a specified TachoLimit goal OUT_RUNSTATE_RUNNING 0x20 Enable power to motors at the specified Power level OUT_RUNSTATE_RAMPDOWN 0x40 Enable ramping down from a current Power to a ne
53. l constants known as IO Map Addresses IOMA Valid IOMA constants are listed in the following table IOMA Constant Parameter Meaning InputIOType p S1 S4 Input Type value InputlOInputMode p S1 S4 Input InputMode value InputIORaw Value p S1 S4 Input RawValue value InputIONormalizedValue p S1 S4 Input Normalized Value value InputIOScaledValue p 1 84 Input ScaledValue value InputIOInvalidData p S1 S4 Input InvalidData value OutputIOUpdateFlags p OUT A OUT C Output UpdateFlags value Page 34 NXC Programmer s Guide OutputIOOutputMode p OUT A OUT Output OutputMode value OutputlOPower p OUT_A OUT_C Output Power value OutputlOActualSpeed p OUT_A OUT_C Output ActualSpeed value OutputIOTachoCount p OUT A OUT Output TachoCount value OutputIOTachoLimit p OUT A OUT Output TachoLimit value OutputIORunState p OUT_A OUT_C Output RunState value OutputIOTurnRatio p OUT A OUT C Output TurnRatio value OutputIORegMode p OUT_A OUT_C Output RegMode value OutputIOOverload p OUT A OUT Output Overload value OutputlORegPValue p OUT_A OUT_C Output RegPValue value OutputIORegIValue p OUT A OUT C Output RegIValue value OutputIORegD Value p OUT A OUT Output RegDValue value OutputlOBlockTachoCount p OUT A OUT C Output BlockTachoCount value OutputIORotationCount p OUT A OUT C
54. n be done via the wait API function or by using the sound state value within a while loop Page 35 NXC Programmer s Guide The NXC API defines frequency and duration constants which may be used in calls to PlayTone or PlayToneEx Frequency constants start with TONE_A3 the A pitch in octave 3 and go to TONE B7 the B pitch in octave 7 Duration constants start with MS 1 1 millisecond and go up to MIN 1 60000 milliseconds with several constants in between See NBCCommon h for the complete list Valid sound flags constants are listed in the following table Sound Flags Constants Read Write Meaning SOUND FLAGS IDLE Read Sound is idle SOUND FLAGS UPDATE Write Make changes take effect SOUND FLAGS RUNNING Read Processing a tone or file Table 18 Sound Flags Constants Valid sound state constants are listed in the following table Read Write Read Sound State Constants SOUND STATE IDLE Meaning Idle ready for start sound SOUND STATE FILE Read Processing file of sound melody data SOUND STATE TONE Read Processing play tone request SOUND STATE STOP Write Stop sound immediately and close hardware Table 19 Sound State Constants Valid sound mode constants are listed in the following table Sound Mode Constants Read Write Meaning SOUND MODE ONCE Read Only play file once SOUND MODE LOOP Read Play file until writing SOUND STATE
55. nally are numbered 0 1 2 and 3 This is potentially confusing since they are externally labeled on the NXT as sensors 1 2 3 and 4 To help mitigate this confusion the sensor port names S1 S2 S3 and SA have been defined These sensor names may be used in any function that requires a sensor port as an argument Alternatively the NBC port name constants IN 1 IN 2 IN_3 and IN 4 may also be used when a sensor port is required Sensor value names SENSOR 1 SENSOR 2 SENSOR 3 and SENSOR 4 have also been defined These names may also be used whenever a program wishes to read the current value of the sensor x SENSOR 1 read sensor and store value in x 3 1 1 Types and Modes The sensor ports on the NXT are capable of interfacing to a variety of different sensors It is up to the program to tell the NXT what kind of sensor is attached to each port Calling SetSensorType configures a sensor s type There are 12 sensor types each corresponding to a specific LEGO RCX or NXT sensor A thirteenth type SENSOR TYPE NONE is used to indicate that no sens or has been configured In general a program should configure the type to match the actual sensor If a sensor port is configured as the wrong type the NXT may not be able to read it accurately Use either the Sensor Type constants or the NBC Sensor Type constants Sensor Type NBC Sensor Type Meaning SENSOR TYPE NONE IN TYPE N
56. nd may not be used as identifiers A complete list of keywords appears below RETURN case inline sub RETVAL char int switch STRRETVAL const long task _ TMPBYTE continue mutex true TMPWORD default repeat typedef _ TMPLONG do return unsigned abs else short until asm false sign void bool for start while break goto string byte if struct Table 1 NXC Keywords 2 2 Program Structure An NXC program is composed of code blocks and variables There are two distinct types of code blocks tasks and functions Each type of code block has its own unique features but they share a common structure 2 2 1 Tasks The NXT supports multi threading so a task in NXC directly corresponds to an NXT thread Tasks are defined using the task keyword using the following syntax Page 3 NXC Programmer s Guide task name the task s code is placed here The name of the task may be any legal identifier A program must always have at least one task named main which is started whenever the program is run The maximum number of tasks is 256 The body of a task consists of a list of statements Scheduling dependant tasks using the Precedes or Follows API function is the primary mechanism supported by the NXT for starting other tasks concurrently Tasks may also be started using the start statement Tasks cannot be stopped by another task however The only way to stop a task is by stopp
57. nsor on port p which must be 0 1 2 or 3 or a sensor port name constant x CustomSensorPercentFullScale S1 CustomSensorA ctiveStatus const p Value Return the custom sensor active status value of a sensor on port p which must be 0 1 2 or 3 or a sensor port name constant x CustomSensorActiveStatus S1 SensorDigiPinsDirection const p Value Return the digital pins direction value of a sensor on port p which must be 0 1 2 or 3 or a sensor port name constant x SensorDigiPinsDirection S1 SensorDigiPinsStatus const p Value Return the digital pins status value of a sensor on port p which must be 0 1 2 or 3 or a sensor port name constant x SensorDigiPinsStatus 1 SensorDigiPinsOutputLevel const p Value Return the digital pins output level value of a sensor on port p which must be 0 1 2 or 3 or a sensor port name constant x SensorDigiPinsOutputLevel 31 3 2 Output Module The NXT output module encompasses all the motor outputs Nearly all of the NXC API functions dealing with outputs take either a single output or a set of outputs as their first Page 23 NXC Programmer s Guide argument The output or set of outputs may be a constant or a variable containing an appropriate output port value The constants OUT A OUT B and OUT C are used to identify the three outputs Unlike NQC adding individual outputs together does not combine multiple outputs Instea
58. nt operators xtt The empty statement just a bare semicolon is also a legal statement 2 4 Expressions Values are the most primitive type of expressions More complicated expressions are formed from values using various operators The NXC language only has two built in kinds of values numerical constants and variables Page 13 NXC Programmer s Guide Numerical constants in the NXT are represented as integers The type depends on the value of the constant NXC internally uses 32 bit signed math for constant expression evaluation Numeric constants can be written as either decimal e g 123 or hexadecimal e g OxABC Presently there is very little range checking on constants so using a value larger than expected may have unusual effects Two special values are predefined true and false The value of false is zero 0 while the value of t rue is one 1 The same values hold for relational operators e g lt when the relation is false the value is O otherwise the value is 1 Values may be combined using operators Several of the operators may only be used in evaluating constant expressions which means that their operands must either be constants or expressions involving nothing but constants The operators are listed here in order of precedence highest to lowest Operator Description Associativity Restriction Example abs Absolute value n a abs x sign
59. o x 1 ok y 2 error y is not global 2 2 4 Structs NXC also support structs TBD 2 2 5 Arrays NXC also support arrays Arrays are declared the same way as ordinary variables but with an open and close bracket following the variable name int my array declare an array with 0 elements To declare arrays with more than one dimension simply add more pairs of square brackets The maximum number of dimensions supported in NXC is 4 bool my array 1 declare a 2 dimensional array Global arrays with one dimension can be initialized at the point of declaration using the following syntax int Xp e i 2 3 45 e A I E arrays The elements of an array are identified by their position within the array called an index The first element has an index of 0 the second has index 1 etc For example Page 7 NXC Programmer s Guide my array 0 123 set first element to 123 my array 1 my array 2 copy third into second Currently there are some limitations on how arrays can be used These limitations will likely be removed in future versions of NXC To initialize local arrays or arrays with multiple dimensions it is necessary to use the ArrayInit function The following example shows how to initialize a two dimensional array using ArrayInit It also demonstrates some of the supported array API functions and expressions include NXCDefs h task main int myArray int myVe
60. on and documentation for NXC visit the NXC website at http bricxcc sourceforge net nxc Page 1 NXC Programmer s Guide 2 The NXC Language This section describes the NXC language itself This includes the lexical rules used by the compiler the structure programs statements and expressions and the operation of the preprocessor NXC is a case sensitive language just like C and C That means that the identifier XYZ is not the same identifier as Xyz Similarly the if statement begins with the keyword if but iF If or IF are all just valid identifiers not keywords 2 1 Lexical Rules The lexical rules describe how NXC breaks a source file into individual tokens This includes the way comments are written the handling of whitespace and valid characters for identifiers 2 1 1 Comments Two forms of comments are supported in NXC The first form traditional C comments begin with and end with They may span multiple lines but do not nest this is a comment this is a two line comment another comment trying to nest ending the inner comment this text is no longer a comment The second form of comments begins with and ends with a newline sometimes known as C style comments a single line comment The compiler ignores comments Their only purpose is to allow the programmer to document the source code 2 1 2 Whitespace Whitespace spa
61. onnectionLinkQuality p n SetBrickDataBluecoreVersion n SetBrickDataBtStateStatus n SetBrickDataBtHardwareStatus n SetBrickDataTimeoutValue n SetBTInputBuffer offset cnt data SetBTInputBufferInPtr n SetBTInputBufferOutPtr n SetB TOutputBuffer offset cnt data SetBTOutputBufferInPtr n SetBTOutputBufferOutPtr n SetBluetoothState n Page 53 NXC Programmer s Guide val BluetoothState result SendRemoteBool conn queue bval result SendRemoteNumber conn queue val result SendRemoteString conn queue str result SendResponseBool queue bval result SendResponseNumber queue val result SendResponseString queue str result ReceiveRemoteBool queue clear bval result ReceiveRemoteNumber queue clear val result ReceiveRemoteString queue clear str result ReceiveRemoteMessageEx queue clear str val bval result RemoteMessageRead conn queue result RemoteMessageWrite conn queue msg result RemoteStartProgram conn filename result RemoteStopProgram conn result RemotePlaySoundFile conn filename bloop result RemotePlay Tone conn frequency duration result RemoteStopSound conn result RemoteKeepAlive conn result RemoteResetScaledValue conn port result RemoteResetMotorPosition conn port brelative result RemoteSetInputMode conn port type mode result RemoteSetOutputState conn port speed mode regmode turnpct runstate t
62. s returned as the value of the function call The handle parameter must be a variable The value parameter must be a constant a constant expression or a variable The type of the value parameter determines the number of bytes of data written result Write handle value WriteLn handle value Value Write a numeric value to the file associated with the specified handle The loader result code is returned as the value of the function call The handle parameter must be a variable The value parameter must be a constant a constant expression or a variable The type of the value parameter determines the number of bytes of data Page 45 NXC Programmer s Guide written The WriteLn function also writes a carriage return and a line feed to the file following the numeric data result WriteLn handle value WriteString handle str out count Value Write the string to the file associated with the specified handle The loader result code is returned as the value of the function call The handle parameter must be a variable The count parameter must be a variable The str parameter must be a string variable or string constant The actual number of bytes written is returned in the count parameter result WriteString handle testing count WriteLnString handle str out count Value Write the string to the file associated with the specified handle The loader result code is returned as the value of the funct
63. sensor 9V powered The port must be specified using a constant e g S1 S2 S3 or SA SetSensorLowspeed 5S1 SetInput port const field value Function Set the specified field of the sensor on the specified port to the value provided The port may be specified using a constant e g S1 S2 S3 or S4 or a variable The field must be a sensor field constant Valid field constants are listed in Table 10 The value may be any valid expression SetInput S1 Type IN TYPE SOUND DB ClearSensor const port Function Clear the value of a sensor only affects sensors that are configured to measure a cumulative quantity such as rotation or a pulse count The port must be specified using a constant e g S1 S2 S3 or S4 ClearSensor S1 ResetSensor port Function Reset the value of a sensor If the sensor type or mode has been modified then the sensor should be reset in order to ensure that values read from the sensor are valid Use a port constant or a variable whose value is the desired sensor port ResetSensor x x S1 SetCustomSensorZeroOffset const p value Function Sets the custom sensor zero offset value of a sensor The port must be specified using a constant e g S1 S2 S3 or S4 SetCustomSensorZeroOffset S1 12 SetCustomSensorPercentFullScale const p value Function Sets the custom sensor percent full scale value of a sensor The port must be specified using
64. ted in Table 16 OnRevRegEx OUT A 75 OUT REGMODE SPEED RESET NONE OnFwdSync outputs pwr turnpct Function Run the specified outputs forward with regulated synchronization using the specified turn ratio Outputs can be OUT AB OUT AC OUT BC or a variable containing one of these values OnFwdSync OUT AB 75 100 spin right OnFwdSyncEx outputs pwr turnpct const reset Function Run the specified outputs forward with regulated synchronization using the specified turn ratio Outputs can be OUT AB OUT AC OUT BC or a variable containing one of these values The reset parameter controls whether any of the three position counters are reset It must be a constant Valid reset values are listed in Table 16 OnFwdSyncEx OUT AB 75 0 RESET NONE OnRevSync outputs pwr turnpct Function Run the specified outputs in reverse with regulated synchronization using the specified turn ratio Outputs can be OUT AB OUT AC OUT BC or a variable containing one of these values OnRevSync OUT AB 75 100 spin left OnRevSyncEx outputs pwr turnpct const reset Function Run the specified outputs in reverse with regulated synchronization using the specified turn ratio Outputs can be OUT AB OUT AC OUT BC or a variable containing one of these values The reset parameter controls whether any of the three position
65. tputBufferInPtr p n SetLSOutputBufferOutPtr p n SetLSOutputBufferB ytesToRx p n SetLSMode p n SetLSChannelState p n SetLSErrorType p n SetLSState n SetLSSpeed n val BluetoothStatus conn val BluetoothWrite conn buffer val BTDeviceCount SetBTDeviceCount n val BTDeviceNameCount SetBTDeviceNameCount n GetBTInputBuffer offset cnt data GetBTOutputBuffer offset cnt data str BTDeviceName p str BTConnectionName p str BTConnectionPinCode p str BrickDataName GetBTDeviceAddress p data GetBTConnectionAddress p data GetBrickDataAddress data val BTDeviceClass p val BTDeviceStatus p val BTConnectionClass p val BTConnectionHandleNum p val BTConnectionStreamStatus p Page 52 NXC Programmer s Guide val BTConnectionLinkQuality p val BrickDataBluecoreVersion val BrickDataBtStateStatus val BrickDataBtHardwareStatus val BrickDataTimeoutV alue val BTInputBufferInPtr val BTInputBufferOutPtr val BTOutputBufferInPtr val BTOutputBufferOutPtr SetBTDeviceName p str SetBTDeviceAddress p addr SetBTConnectionName p str SetBTConnectionPinCode p code SetBTConnectionAddress p addr SetBrickDataName str SetBrickDataAddress p addr SetBTDeviceClass p n SetBTDeviceStatus p n SetBTConnectionClass p n SetBTConnectionHandleNum p n SetBTConnectionStreamStatus p n SetBTC
66. ttery power To use motor regulation include OUT MODE REGULATED in the OutputMode value Use UF UPDATE MODE with UpdateFlags to commit changes to this field Power sbyte Read Write 100 100 Specify the power level of the output The absolute value of Power is a percentage of the full power of the motor The sign of Power controls the rotation direction Positive values tell the firmware to turn the motor forward while negative values turn the motor backward Use UF UPDATE POWER with UpdateFlags to commit changes to this field ActualSpeed sbyte Read 100 100 Return the percent of full power the firmware is applying to the output This may vary from the Power value when auto regulation code in the firmware responds to a load on the output TachoCount slong Read full range of signed long Return the internal position counter value for the specified output The internal count is reset automatically when a new goal is set using the TachoLimit and the UF UPDATE TACHO LIMIT flag Set the UF UPDATE RESET COUNT flag in UpdateFlags to reset TachoCount and cancel any TachoLimit The sign of TachoCount indicates the motor rotation direction Page 24 NXC Programmer s Guide TachoLimit ulong Read Write full range of unsigned long Specify the number of degrees the motor should rotate Use UF UPDATE TACHO LIMIT with the UpdateFlags field to commit
67. usly BlockTachoCount slong Read full range of signed long Return the block relative position counter value for the specified port Refer to the UpdateFlags description for information about how to use block relative position counts Set the UF_UPDATE_RESET_BLOCK_COUNT flag in UpdateFlags to request that the firmware reset the BlockTachoCount The sign of BlockTachoCount indicates the direction of rotation Positive values indicate forward rotation and negative values indicate reverse rotation Forward and reverse depend on the orientation of the motor RotationCount slong Read full range of signed long Return the program relative position counter value for the specified port Refer to the UpdateFlags description for information about how to use program relative position counts Set the UF_UPDATE_RESET_ROTATION_COUNT flag in UpdateFlags to request that the firmware reset the RotationCount The sign of RotationCount indicates the direction of rotation Positive values indicate forward rotation and negative values indicate reverse rotation Forward and reverse depend on the orientation of the motor Table 11 Output Field Constants Page 26 NXC Programmer s Guide Valid UpdateFlags values are described in the following table UpdateFlags Constants Meaning UF UPDATE MODE Commits changes to the OutputMode output property UF UPDATE SPEED Comm
68. utBufferInPtr val USBOutputBufferOutPtr val USBPollBufferInPtr val USBPollBufferOutPtr val USBState GetHSInputBuffer offset cnt data GetHSOutputBuffer offset cnt data val HSInputBufferInPtr val HSInputBufferOutPtr val HSOutputBufferInPtr val HSOutputBufferOutPtr val HSFlags val HSSpeed val HSState Page 50 NXC Programmer s Guide SetHSInputBuffer offset cnt data SetHSInputBufferInPtr n SetHSInputBufferOutPtr n SetHSOutputBuffer offset cnt data SetHSOutputBufferInPtr n SetHSOutputBufferOutPtr n SetHSFlags n SetHSSpeed n SetHSState n val SendMessage queue msg val ReceiveMessage queue clear msg val LowspeedStatus port bready val LowspeedWrite port retlen buffer val LowspeedRead port buflen buffer GetLSInputBuffer p offset cnt data GetLSOutputBuffer p offset cnt data val LSInputBufferInPtr p val LSInputBufferOutPtr p val LSInputBufferB ytesToRx p val LSOutputBufferInPtr p val LSOutputBufferOutPtr p val LSOutputBufferBytesToRx p val LSMode p val LSChannelState p val LSErrorType p val LSState val 2 LSSpeed SetLSInputBuffer p offset cnt data SetLSInputBufferInPtr p n SetLSInputBufferOutPtr p n Page 51 NXC Programmer s Guide SetLSInputBufferBytesToRx p n SetLSOutputBuffer p offset cnt data SetLSOu
69. value is the desired sensor port may also be used x Sensor S1 read sensor 1 SensorUS n Value Return the processed sensor reading for an ultrasonic sensor on port n where n is 0 1 2 or 3 or a sensor port name constant Since an ultrasonic sensor is an I2C digital sensor its value cannot be read using the standard Sensor n value A variable whose value is the desired sensor port may also be used x SensorUS S4 read sensor 4 SensorType n Value Return the configured type of a sensor on port n which must be 0 1 2 or3 ora sensor port name constant A variable whose value is the desired sensor port may also be used x SensorType S1 Page 21 NXC Programmer s Guide SensorMode n Value Return the current sensor mode for a sensor on port n which must be 0 1 2 or 3 or a sensor port name constant A variable whose value is the desired sensor port may also be used x SensorMode S1 SensorRaw n Value Return the raw value of a sensor on port n which must be 0 1 2 or 3 or a sensor port name constant A variable whose value is the desired sensor port may also be used x SensorRaw 1 SensorNormalized n Value Return the normalized value of a sensor on port n which must be 0 1 2 or 3 ora sensor port name constant A variable whose value is the desired sensor port may also be used x SensorNormalized S1 SensorScaled n Value Return the scaled
70. value of a sensor on port n which must be 0 1 2 or 3 or a sensor port name constant A variable whose value is the desired sensor port may also be used This is the same as the standard Sensor n value x SensorScaled S1 SensorInvalid n Value Return the value of the InvalidData flag of a sensor on port n which must be 0 1 2 or 3 or a sensor port name constant A variable whose value is the desired sensor port may also be used x SensorInvalid S1 SensorBoolean const n Value Return the boolean value of a sensor on port n which must be 0 1 2 or 3 or a sensor port name constant Boolean conversion is either done based on preset cutoffs or a slope parameter specified by calling SetSensorMode x SensorBoolean S1 Page 22 NXC Programmer s Guide GetInput n const field Value Return the value of the specified field of a sensor on port n which must be 0 1 2 or 3 or a sensor port name constant A variable whose value is the desired sensor port may also be used The field must be a sensor field constant Valid field constants are listed in Table 10 x GetInput S1 Type CustomSensorZeroOffset const p Value Return the custom sensor zero offset value of a sensor on port p which must be 0 1 2 or 3 or a sensor port name constant x CustomSensorZeroOffset S1 CustomSensorPercentFullScale const p Value Return the custom sensor percent full scale value of a se
71. w lower Power over a specified TachoLimit goal Table 14 RunState Constants Valid RegMode values are described in the following table RegMode Constants Value Meaning OUT REGMODE IDLE 0x00 No regulation OUT REGMODE SPEED 0x01 Regulate a motor s speed Power OUT REGMODE SYNC 0x02 Synchronize the rotation of two motors Table 15 RegMode Constants 3 2 1 Convenience Calls Since control of outputs is such a common feature of programs a number of convenience functions are provided that make it easy to work with the outputs It should be noted that most of these commands do not provide any new functionality above lower level calls described in the following section They are merely convenient ways to make programs more concise The Ex versions of the motor functions use special reset constants They are defined in the following table Page 27 NXC Programmer s Guide Reset Constants Value RESET NONE 0x00 RESET COUNT 0x08 RESET BLOCK COUNT 0x20 RESET ROTATION COUNT 0x40 RESET BLOCKANDTACHO 0x28 RESET ALL 0x68 Table 16 Reset Constants Off outputs Function Turn the specified outputs off with braking Outputs can be OUT A OUT B OUT C OUT AB OUT AC OUT BC OUT ABC or a variable containing one of these values Off OUT A turn off output A OffEx outputs const reset Function Turn the specified outputs off w

Not eXactly C (NXC)

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