." Process this file with ." groff -man -Tascii pigpiod_if.3 ." .TH pigpiod_if 3 2012-2015 Linux "pigpio archive" .SH NAME pigpiod_if - A C library to interface to the pigpio daemon. .SH SYNOPSIS #include gcc -Wall -pthread -o prog prog.c -lpigpiod_if -lrt ./prog .SH DESCRIPTION .br .br THIS LIBRARY IS DEPRECATED. NEW CODE SHOULD BE WRITTEN TO USE THE MORE VERSATILE pigpiod_if2 LIBRARY. .br .br pigpiod_if is a C library for the Raspberry which allows control of the gpios via the socket interface to the pigpio daemon. .br .br .br .SS Features .br .br o PWM on any of gpios 0-31 .br .br o servo pulses on any of gpios 0-31 .br .br o callbacks when any of gpios 0-31 change state .br .br o callbacks at timed intervals .br .br o reading/writing all of the gpios in a bank as one operation .br .br o individually setting gpio modes, reading and writing .br .br o notifications when any of gpios 0-31 change state .br .br o the construction of output waveforms with microsecond timing .br .br o rudimentary permission control over gpios .br .br o a simple interface to start and stop new threads .br .br o I2C, SPI, and serial link wrappers .br .br o creating and running scripts on the pigpio daemon .br .br .SS gpios .br .br ALL gpios are identified by their Broadcom number. .br .br .SS Notes .br .br The PWM and servo pulses are timed using the DMA and PWM/PCM peripherals. .br .br .SS Usage .br .br Include in your source files. .br .br Assuming your source is in prog.c use the following command to build .br .br .EX gcc -Wall -pthread -o prog prog.c -lpigpiod_if -lrt .br .EE .br .br to run make sure the pigpio daemon is running .br .br .EX sudo pigpiod .br .br ./prog # sudo is not required to run programs linked to pigpiod_if .br .EE .br .br For examples see x_pigpiod_if.c within the pigpio archive file. .br .br .SS Notes .br .br All the functions which return an int return < 0 on error .br .br .SH FUNCTIONS .IP "\fBdouble time_time(void)\fP" .IP "" 4 Return the current time in seconds since the Epoch. .IP "\fBvoid time_sleep(double seconds)\fP" .IP "" 4 Delay execution for a given number of seconds. .br .br .EX seconds: the number of seconds to delay. .br .EE .IP "\fBchar *pigpio_error(int errnum)\fP" .IP "" 4 Return a text description for an error code. .br .br .EX errnum: the error code. .br .EE .IP "\fBunsigned pigpiod_if_version(void)\fP" .IP "" 4 Return the pigpiod_if version. .IP "\fBpthread_t *start_thread(gpioThreadFunc_t thread_func, void *userdata)\fP" .IP "" 4 Starts a new thread of execution with thread_func as the main routine. .br .br .EX thread_func: the main function for the new thread. .br userdata: a pointer to an arbitrary argument. .br .EE .br .br Returns a pointer to pthread_t if OK, otherwise NULL. .br .br The function is passed the single argument userdata. .br .br The thread can be cancelled by passing the pointer to pthread_t to \fBstop_thread\fP. .IP "\fBvoid stop_thread(pthread_t *pth)\fP" .IP "" 4 Cancels the thread pointed at by pth. .br .br .EX pth: the thread to be stopped. .br .EE .br .br No value is returned. .br .br The thread to be stopped should have been started with \fBstart_thread\fP. .IP "\fBint pigpio_start(char *addrStr, char *portStr)\fP" .IP "" 4 Connect to the pigpio daemon. Reserving command and notification streams. .br .br .EX addrStr: specifies the host or IP address of the Pi running the .br pigpio daemon. It may be NULL in which case localhost .br is used unless overridden by the PIGPIO_ADDR environment .br variable. .br .br portStr: specifies the port address used by the Pi running the .br pigpio daemon. It may be NULL in which case "8888" .br is used unless overridden by the PIGPIO_PORT environment .br variable. .br .EE .IP "\fBvoid pigpio_stop(void)\fP" .IP "" 4 Terminates the connection to the pigpio daemon and releases resources used by the library. .IP "\fBint set_mode(unsigned gpio, unsigned mode)\fP" .IP "" 4 Set the gpio mode. .br .br .EX gpio: 0-53. .br mode: PI_INPUT, PI_OUTPUT, PI_ALT0, _ALT1, .br PI_ALT2, PI_ALT3, PI_ALT4, PI_ALT5. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_GPIO, PI_BAD_MODE, or PI_NOT_PERMITTED. .IP "\fBint get_mode(unsigned gpio)\fP" .IP "" 4 Get the gpio mode. .br .br .EX gpio: 0-53. .br .EE .br .br Returns the gpio mode if OK, otherwise PI_BAD_GPIO. .IP "\fBint set_pull_up_down(unsigned gpio, unsigned pud)\fP" .IP "" 4 Set or clear the gpio pull-up/down resistor. .br .br .EX gpio: 0-53. .br pud: PI_PUD_UP, PI_PUD_DOWN, PI_PUD_OFF. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_GPIO, PI_BAD_PUD, or PI_NOT_PERMITTED. .IP "\fBint gpio_read(unsigned gpio)\fP" .IP "" 4 Read the gpio level. .br .br .EX gpio:0-53. .br .EE .br .br Returns the gpio level if OK, otherwise PI_BAD_GPIO. .IP "\fBint gpio_write(unsigned gpio, unsigned level)\fP" .IP "" 4 Write the gpio level. .br .br .EX gpio: 0-53. .br level: 0, 1. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_GPIO, PI_BAD_LEVEL, or PI_NOT_PERMITTED. .br .br Notes .br .br If PWM or servo pulses are active on the gpio they are switched off. .IP "\fBint set_PWM_dutycycle(unsigned user_gpio, unsigned dutycycle)\fP" .IP "" 4 Start (non-zero dutycycle) or stop (0) PWM pulses on the gpio. .br .br .EX user_gpio: 0-31. .br dutycycle: 0-range (range defaults to 255). .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_DUTYCYCLE, or PI_NOT_PERMITTED. Notes .br .br The \fBset_PWM_range\fP function may be used to change the default range of 255. .IP "\fBint get_PWM_dutycycle(unsigned user_gpio)\fP" .IP "" 4 Return the PWM dutycycle in use on a gpio. .br .br .EX user_gpio: 0-31. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO or PI_NOT_PWM_GPIO. .br .br For normal PWM the dutycycle will be out of the defined range for the gpio (see \fBget_PWM_range\fP). .br .br If a hardware clock is active on the gpio the reported dutycycle will be 500000 (500k) out of 1000000 (1M). .br .br If hardware PWM is active on the gpio the reported dutycycle will be out of a 1000000 (1M). .IP "\fBint set_PWM_range(unsigned user_gpio, unsigned range)\fP" .IP "" 4 Set the range of PWM values to be used on the gpio. .br .br .EX user_gpio: 0-31. .br range: 25-40000. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_DUTYRANGE, or PI_NOT_PERMITTED. .br .br Notes .br .br If PWM is currently active on the gpio its dutycycle will be scaled to reflect the new range. .br .br The real range, the number of steps between fully off and fully on for each of the 18 available gpio frequencies is .br .br .EX 25(#1), 50(#2), 100(#3), 125(#4), 200(#5), 250(#6), .br 400(#7), 500(#8), 625(#9), 800(#10), 1000(#11), 1250(#12), .br 2000(#13), 2500(#14), 4000(#15), 5000(#16), 10000(#17), 20000(#18) .br .EE .br .br The real value set by set_PWM_range is (dutycycle * real range) / range. .IP "\fBint get_PWM_range(unsigned user_gpio)\fP" .IP "" 4 Get the range of PWM values being used on the gpio. .br .br .EX user_gpio: 0-31. .br .EE .br .br Returns the dutycycle range used for the gpio if OK, otherwise PI_BAD_USER_GPIO. .br .br If a hardware clock or hardware PWM is active on the gpio the reported range will be 1000000 (1M). .IP "\fBint get_PWM_real_range(unsigned user_gpio)\fP" .IP "" 4 Get the real underlying range of PWM values being used on the gpio. .br .br .EX user_gpio: 0-31. .br .EE .br .br Returns the real range used for the gpio if OK, otherwise PI_BAD_USER_GPIO. .br .br If a hardware clock is active on the gpio the reported real range will be 1000000 (1M). .br .br If hardware PWM is active on the gpio the reported real range will be approximately 250M divided by the set PWM frequency. .br .br .IP "\fBint set_PWM_frequency(unsigned user_gpio, unsigned frequency)\fP" .IP "" 4 Set the frequency (in Hz) of the PWM to be used on the gpio. .br .br .EX user_gpio: 0-31. .br frequency: 0- (Hz). .br .EE .br .br Returns the numerically closest frequency if OK, otherwise PI_BAD_USER_GPIO or PI_NOT_PERMITTED. .br .br The selectable frequencies depend upon the sample rate which may be 1, 2, 4, 5, 8, or 10 microseconds (default 5). The sample rate is set when the C pigpio library is started. .br .br Each gpio can be independently set to one of 18 different PWM frequencies. .br .br If PWM is currently active on the gpio it will be switched off and then back on at the new frequency. .br .br .EX 1us 40000, 20000, 10000, 8000, 5000, 4000, 2500, 2000, 1600, .br 1250, 1000, 800, 500, 400, 250, 200, 100, 50 .br .br 2us 20000, 10000, 5000, 4000, 2500, 2000, 1250, 1000, 800, .br 625, 500, 400, 250, 200, 125, 100, 50 , 25 .br .br 4us 10000, 5000, 2500, 2000, 1250, 1000, 625, 500, 400, .br 313, 250, 200, 125, 100, 63, 50, 25, 13 .br .br 5us 8000, 4000, 2000, 1600, 1000, 800, 500, 400, 320, .br 250, 200, 160, 100 , 80, 50, 40, 20, 10 .br .br 8us 5000, 2500, 1250, 1000, 625, 500, 313, 250, 200, .br 156, 125, 100, 63, 50, 31, 25, 13, 6 .br .br 10us 4000, 2000, 1000, 800, 500, 400, 250, 200, 160, .br 125, 100, 80, 50, 40, 25, 20, 10, 5 .br .EE .IP "\fBint get_PWM_frequency(unsigned user_gpio)\fP" .IP "" 4 Get the frequency of PWM being used on the gpio. .br .br .EX user_gpio: 0-31. .br .EE .br .br For normal PWM the frequency will be that defined for the gpio by \fBset_PWM_frequency\fP. .br .br If a hardware clock is active on the gpio the reported frequency will be that set by \fBhardware_clock\fP. .br .br If hardware PWM is active on the gpio the reported frequency will be that set by \fBhardware_PWM\fP. .br .br Returns the frequency (in hertz) used for the gpio if OK, otherwise PI_BAD_USER_GPIO. .IP "\fBint set_servo_pulsewidth(unsigned user_gpio, unsigned pulsewidth)\fP" .IP "" 4 Start (500-2500) or stop (0) servo pulses on the gpio. .br .br .EX user_gpio: 0-31. .br pulsewidth: 0 (off), 500 (anti-clockwise) - 2500 (clockwise). .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_PULSEWIDTH or PI_NOT_PERMITTED. .br .br The selected pulsewidth will continue to be transmitted until changed by a subsequent call to set_servo_pulsewidth. .br .br The pulsewidths supported by servos varies and should probably be determined by experiment. A value of 1500 should always be safe and represents the mid-point of rotation. .br .br You can DAMAGE a servo if you command it to move beyond its limits. .br .br OTHER UPDATE RATES: .br .br This function updates servos at 50Hz. If you wish to use a different update frequency you will have to use the PWM functions. .br .br .EX Update Rate (Hz) 50 100 200 400 500 .br 1E6/Hz 20000 10000 5000 2500 2000 .br .EE .br .br Firstly set the desired PWM frequency using \fBset_PWM_frequency\fP. .br .br Then set the PWM range using \fBset_PWM_range\fP to 1E6/Hz. Doing this allows you to use units of microseconds when setting the servo pulsewidth. .br .br E.g. If you want to update a servo connected to gpio 25 at 400Hz .br .br .EX set_PWM_frequency(25, 400); .br set_PWM_range(25, 2500); .br .EE .br .br Thereafter use the \fBset_PWM_dutycycle\fP function to move the servo, e.g. set_PWM_dutycycle(25, 1500) will set a 1500 us pulse. .br .IP "\fBint get_servo_pulsewidth(unsigned user_gpio)\fP" .IP "" 4 Return the servo pulsewidth in use on a gpio. .br .br .EX user_gpio: 0-31. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO or PI_NOT_SERVO_GPIO. .IP "\fBint notify_open(void)\fP" .IP "" 4 Get a free notification handle. .br .br Returns a handle greater than or equal to zero if OK, otherwise PI_NO_HANDLE. .br .br A notification is a method for being notified of gpio state changes via a pipe. .br .br Pipes are only accessible from the local machine so this function serves no purpose if you are using the library from a remote machine. The in-built (socket) notifications provided by \fBcallback\fP should be used instead. .br .br Notifications for handle x will be available at the pipe named /dev/pigpiox (where x is the handle number). E.g. if the function returns 15 then the notifications must be read from /dev/pigpio15. .IP "\fBint notify_begin(unsigned handle, uint32_t bits)\fP" .IP "" 4 Start notifications on a previously opened handle. .br .br .EX handle: 0-31 (as returned by \fBnotify_open\fP) .br bits: a mask indicating the gpios to be notified. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE. .br .br The notification sends state changes for each gpio whose corresponding bit in bits is set. .br .br Notes .br .br Each notification occupies 12 bytes in the fifo as follows: .br .br .EX H (16 bit) seqno .br H (16 bit) flags .br I (32 bit) tick .br I (32 bit) level .br .EE .IP "\fBint notify_pause(unsigned handle)\fP" .IP "" 4 Pause notifications on a previously opened handle. .br .br .EX handle: 0-31 (as returned by \fBnotify_open\fP) .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE. .br .br Notifications for the handle are suspended until \fBnotify_begin\fP is called again. .IP "\fBint notify_close(unsigned handle)\fP" .IP "" 4 Stop notifications on a previously opened handle and release the handle for reuse. .br .br .EX handle: 0-31 (as returned by \fBnotify_open\fP) .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE. .IP "\fBint set_watchdog(unsigned user_gpio, unsigned timeout)\fP" .IP "" 4 Sets a watchdog for a gpio. .br .br .EX user_gpio: 0-31. .br timeout: 0-60000. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO or PI_BAD_WDOG_TIMEOUT. .br .br The watchdog is nominally in milliseconds. .br .br Only one watchdog may be registered per gpio. .br .br The watchdog may be cancelled by setting timeout to 0. .br .br If no level change has been detected for the gpio for timeout milliseconds any notification for the gpio has a report written to the fifo with the flags set to indicate a watchdog timeout. .br .br The \fBcallback\fP and \fBcallback_ex\fP functions interpret the flags and will call registered callbacks for the gpio with level TIMEOUT. .IP "\fBint set_glitch_filter(unsigned user_gpio, unsigned steady)\fP" .IP "" 4 Sets a glitch filter on a gpio. .br .br Level changes on the gpio are not reported unless the level has been stable for at least \fBsteady\fP microseconds. The level is then reported. Level changes of less than \fBsteady\fP microseconds are ignored. .br .br .EX user_gpio: 0-31 .br steady: 0-300000 .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO, or PI_BAD_FILTER. .br .br Note, each (stable) edge will be timestamped \fBsteady\fP microseconds after it was first detected. .IP "\fBint set_noise_filter(unsigned user_gpio, unsigned steady, unsigned active)\fP" .IP "" 4 Sets a noise filter on a gpio. .br .br Level changes on the gpio are ignored until a level which has been stable for \fBsteady\fP microseconds is detected. Level changes on the gpio are then reported for \fBactive\fP microseconds after which the process repeats. .br .br .EX user_gpio: 0-31 .br steady: 0-300000 .br active: 0-1000000 .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO, or PI_BAD_FILTER. .br .br Note, level changes before and after the active period may be reported. Your software must be designed to cope with such reports. .IP "\fBuint32_t read_bank_1(void)\fP" .IP "" 4 Read the levels of the bank 1 gpios (gpios 0-31). .br .br The returned 32 bit integer has a bit set if the corresponding gpio is logic 1. Gpio n has bit value (1<=0, as returned by \fBwave_create\fP. .br .EE .br .br Wave ids are allocated in order, 0, 1, 2, etc. .br .br Returns 0 if OK, otherwise PI_BAD_WAVE_ID. .IP "\fBint wave_send_once(unsigned wave_id)\fP" .IP "" 4 This function transmits the waveform with id wave_id. The waveform is sent once. .br .br NOTE: Any hardware PWM started by \fBhardware_PWM\fP will be cancelled. .br .br .EX wave_id: >=0, as returned by \fBwave_create\fP. .br .EE .br .br Returns the number of DMA control blocks in the waveform if OK, otherwise PI_BAD_WAVE_ID, or PI_BAD_WAVE_MODE. .IP "\fBint wave_send_repeat(unsigned wave_id)\fP" .IP "" 4 This function transmits the waveform with id wave_id. The waveform cycles until cancelled (either by the sending of a new waveform or by \fBwave_tx_stop\fP). .br .br NOTE: Any hardware PWM started by \fBhardware_PWM\fP will be cancelled. .br .br .EX wave_id: >=0, as returned by \fBwave_create\fP. .br .EE .br .br Returns the number of DMA control blocks in the waveform if OK, otherwise PI_BAD_WAVE_ID, or PI_BAD_WAVE_MODE. .IP "\fBint wave_chain(char *buf, unsigned bufSize)\fP" .IP "" 4 This function transmits a chain of waveforms. .br .br NOTE: Any hardware PWM started by \fBhardware_PWM\fP will be cancelled. .br .br The waves to be transmitted are specified by the contents of buf which contains an ordered list of \fBwave_id\fPs and optional command codes and related data. .br .br .EX buf: pointer to the wave_ids and optional command codes .br bufSize: the number of bytes in buf .br .EE .br .br Returns 0 if OK, otherwise PI_CHAIN_NESTING, PI_CHAIN_LOOP_CNT, PI_BAD_CHAIN_LOOP, PI_BAD_CHAIN_CMD, PI_CHAIN_COUNTER, PI_BAD_CHAIN_DELAY, PI_CHAIN_TOO_BIG, or PI_BAD_WAVE_ID. .br .br Each wave is transmitted in the order specified. A wave may occur multiple times per chain. .br .br A blocks of waves may be transmitted multiple times by using the loop commands. The block is bracketed by loop start and end commands. Loops may be nested. .br .br Delays between waves may be added with the delay command. .br .br The following command codes are supported: .br .br Name Cmd & Data Meaning .br Loop Start 255 0 Identify start of a wave block .br Loop Repeat 255 1 x y loop x + y*256 times .br Delay 255 2 x y delay x + y*256 microseconds .br Loop Forever 255 3 loop forever .br .br .br If present Loop Forever must be the last entry in the chain. .br .br The code is currently dimensioned to support a chain with roughly 600 entries and 20 loop counters. .br .br \fBExample\fP .br .EX #include .br #include .br .br #define WAVES 5 .br #define GPIO 4 .br .br int main(int argc, char *argv[]) .br { .br int i, wid[WAVES]; .br .br if (pigpio_start(0, 0)<0) return -1; .br .br set_mode(GPIO, PI_OUTPUT); .br .br for (i=0; i=0, as returned by \fBstore_script\fP. .br numPar: 0-10, the number of parameters. .br param: an array of parameters. .br .EE .br .br The function returns 0 if OK, otherwise PI_BAD_SCRIPT_ID, or PI_TOO_MANY_PARAM .br .br param is an array of up to 10 parameters which may be referenced in the script as p0 to p9. .IP "\fBint script_status(unsigned script_id, uint32_t *param)\fP" .IP "" 4 This function returns the run status of a stored script as well as the current values of parameters 0 to 9. .br .br .EX script_id: >=0, as returned by \fBstore_script\fP. .br param: an array to hold the returned 10 parameters. .br .EE .br .br The function returns greater than or equal to 0 if OK, otherwise PI_BAD_SCRIPT_ID. .br .br The run status may be .br .br .EX PI_SCRIPT_INITING .br PI_SCRIPT_HALTED .br PI_SCRIPT_RUNNING .br PI_SCRIPT_WAITING .br PI_SCRIPT_FAILED .br .EE .br .br The current value of script parameters 0 to 9 are returned in param. .IP "\fBint stop_script(unsigned script_id)\fP" .IP "" 4 This function stops a running script. .br .br .EX script_id: >=0, as returned by \fBstore_script\fP. .br .EE .br .br The function returns 0 if OK, otherwise PI_BAD_SCRIPT_ID. .IP "\fBint delete_script(unsigned script_id)\fP" .IP "" 4 This function deletes a stored script. .br .br .EX script_id: >=0, as returned by \fBstore_script\fP. .br .EE .br .br The function returns 0 if OK, otherwise PI_BAD_SCRIPT_ID. .IP "\fBint bb_serial_read_open(unsigned user_gpio, unsigned baud, unsigned data_bits)\fP" .IP "" 4 This function opens a gpio for bit bang reading of serial data. .br .br .EX user_gpio: 0-31. .br baud: 50-250000 .br data_bits: 1-32 .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_WAVE_BAUD, or PI_GPIO_IN_USE. .br .br The serial data is returned in a cyclic buffer and is read using bb_serial_read. .br .br It is the caller's responsibility to read data from the cyclic buffer in a timely fashion. .IP "\fBint bb_serial_read(unsigned user_gpio, void *buf, size_t bufSize)\fP" .IP "" 4 This function copies up to bufSize bytes of data read from the bit bang serial cyclic buffer to the buffer starting at buf. .br .br .EX user_gpio: 0-31, previously opened with \fBbb_serial_read_open\fP. .br buf: an array to receive the read bytes. .br bufSize: 0- .br .EE .br .br Returns the number of bytes copied if OK, otherwise PI_BAD_USER_GPIO or PI_NOT_SERIAL_GPIO. .br .br The bytes returned for each character depend upon the number of data bits \fBdata_bits\fP specified in the \fBbb_serial_read_open\fP command. .br .br For \fBdata_bits\fP 1-8 there will be one byte per character. .br For \fBdata_bits\fP 9-16 there will be two bytes per character. .br For \fBdata_bits\fP 17-32 there will be four bytes per character. .IP "\fBint bb_serial_read_close(unsigned user_gpio)\fP" .IP "" 4 This function closes a gpio for bit bang reading of serial data. .br .br .EX user_gpio: 0-31, previously opened with \fBbb_serial_read_open\fP. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO, or PI_NOT_SERIAL_GPIO. .IP "\fBint bb_serial_invert(unsigned user_gpio, unsigned invert)\fP" .IP "" 4 This function inverts serial logic for big bang serial reads. .br .br .EX user_gpio: 0-31, previously opened with \fBbb_serial_read_open\fP. .br invert: 0-1, 1 invert, 0 normal. .br .EE .br .br Returns 0 if OK, otherwise PI_NOT_SERIAL_GPIO or PI_BAD_SER_INVERT. .IP "\fBint i2c_open(unsigned i2c_bus, unsigned i2c_addr, unsigned i2c_flags)\fP" .IP "" 4 This returns a handle for the device at address i2c_addr on bus i2c_bus. .br .br .EX i2c_bus: 0-1. .br i2c_addr: 0x00-0x7F. .br i2c_flags: 0. .br .EE .br .br No flags are currently defined. This parameter should be set to zero. .br .br Returns a handle (>=0) if OK, otherwise PI_BAD_I2C_BUS, PI_BAD_I2C_ADDR, PI_BAD_FLAGS, PI_NO_HANDLE, or PI_I2C_OPEN_FAILED. .br .br For the SMBus commands the low level transactions are shown at the end of the function description. The following abbreviations are used. .br .br .EX S (1 bit) : Start bit .br P (1 bit) : Stop bit .br Rd/Wr (1 bit) : Read/Write bit. Rd equals 1, Wr equals 0. .br A, NA (1 bit) : Accept and not accept bit. .br .br .br Addr (7 bits): I2C 7 bit address. .br Comm (8 bits): Command byte, a data byte which often selects a register. .br Data (8 bits): A data byte. .br Count (8 bits): A data byte containing the length of a block operation. .br .br [..]: Data sent by the device. .br .EE .IP "\fBint i2c_close(unsigned handle)\fP" .IP "" 4 This closes the I2C device associated with the handle. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE. .IP "\fBint i2c_write_quick(unsigned handle, unsigned bit)\fP" .IP "" 4 This sends a single bit (in the Rd/Wr bit) to the device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br bit: 0-1, the value to write. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED. .br .br Quick command. SMBus 2.0 5.5.1 .EX S Addr Rd/Wr [A] P .br .EE .IP "\fBint i2c_write_byte(unsigned handle, unsigned bVal)\fP" .IP "" 4 This sends a single byte to the device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br bVal: 0-0xFF, the value to write. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED. .br .br Send byte. SMBus 2.0 5.5.2 .EX S Addr Wr [A] Data [A] P .br .EE .IP "\fBint i2c_read_byte(unsigned handle)\fP" .IP "" 4 This reads a single byte from the device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br .EE .br .br Returns the byte read (>=0) if OK, otherwise PI_BAD_HANDLE, or PI_I2C_READ_FAILED. .br .br Receive byte. SMBus 2.0 5.5.3 .EX S Addr Rd [A] [Data] NA P .br .EE .IP "\fBint i2c_write_byte_data(unsigned handle, unsigned i2c_reg, unsigned bVal)\fP" .IP "" 4 This writes a single byte to the specified register of the device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br i2c_reg: 0-255, the register to write. .br bVal: 0-0xFF, the value to write. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED. .br .br Write byte. SMBus 2.0 5.5.4 .EX S Addr Wr [A] Comm [A] Data [A] P .br .EE .IP "\fBint i2c_write_word_data(unsigned handle, unsigned i2c_reg, unsigned wVal)\fP" .IP "" 4 This writes a single 16 bit word to the specified register of the device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br i2c_reg: 0-255, the register to write. .br wVal: 0-0xFFFF, the value to write. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED. .br .br Write word. SMBus 2.0 5.5.4 .EX S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] P .br .EE .IP "\fBint i2c_read_byte_data(unsigned handle, unsigned i2c_reg)\fP" .IP "" 4 This reads a single byte from the specified register of the device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br i2c_reg: 0-255, the register to read. .br .EE .br .br Returns the byte read (>=0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED. .br .br Read byte. SMBus 2.0 5.5.5 .EX S Addr Wr [A] Comm [A] S Addr Rd [A] [Data] NA P .br .EE .IP "\fBint i2c_read_word_data(unsigned handle, unsigned i2c_reg)\fP" .IP "" 4 This reads a single 16 bit word from the specified register of the device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br i2c_reg: 0-255, the register to read. .br .EE .br .br Returns the word read (>=0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED. .br .br Read word. SMBus 2.0 5.5.5 .EX S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P .br .EE .IP "\fBint i2c_process_call(unsigned handle, unsigned i2c_reg, unsigned wVal)\fP" .IP "" 4 This writes 16 bits of data to the specified register of the device associated with handle and and reads 16 bits of data in return. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br i2c_reg: 0-255, the register to write/read. .br wVal: 0-0xFFFF, the value to write. .br .EE .br .br Returns the word read (>=0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED. .br .br Process call. SMBus 2.0 5.5.6 .EX S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] .br S Addr Rd [A] [DataLow] A [DataHigh] NA P .br .EE .IP "\fBint i2c_write_block_data(unsigned handle, unsigned i2c_reg, char *buf, unsigned count)\fP" .IP "" 4 This writes up to 32 bytes to the specified register of the device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br i2c_reg: 0-255, the register to write. .br buf: an array with the data to send. .br count: 1-32, the number of bytes to write. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED. .br .br Block write. SMBus 2.0 5.5.7 .EX S Addr Wr [A] Comm [A] Count [A] Data [A] Data [A] ... [A] Data [A] P .br .EE .IP "\fBint i2c_read_block_data(unsigned handle, unsigned i2c_reg, char *buf)\fP" .IP "" 4 This reads a block of up to 32 bytes from the specified register of the device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br i2c_reg: 0-255, the register to read. .br buf: an array to receive the read data. .br .EE .br .br The amount of returned data is set by the device. .br .br Returns the number of bytes read (>=0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED. .br .br Block read. SMBus 2.0 5.5.7 .EX S Addr Wr [A] Comm [A] .br S Addr Rd [A] [Count] A [Data] A [Data] A ... A [Data] NA P .br .EE .IP "\fBint i2c_block_process_call(unsigned handle, unsigned i2c_reg, char *buf, unsigned count)\fP" .IP "" 4 This writes data bytes to the specified register of the device associated with handle and reads a device specified number of bytes of data in return. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br i2c_reg: 0-255, the register to write/read. .br buf: an array with the data to send and to receive the read data. .br count: 1-32, the number of bytes to write. .br .EE .br .br .br .br Returns the number of bytes read (>=0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED. .br .br The smbus 2.0 documentation states that a minimum of 1 byte may be sent and a minimum of 1 byte may be received. The total number of bytes sent/received must be 32 or less. .br .br Block write-block read. SMBus 2.0 5.5.8 .EX S Addr Wr [A] Comm [A] Count [A] Data [A] ... .br S Addr Rd [A] [Count] A [Data] ... A P .br .EE .IP "\fBint i2c_read_i2c_block_data(unsigned handle, unsigned i2c_reg, char *buf, unsigned count)\fP" .IP "" 4 This reads count bytes from the specified register of the device associated with handle . The count may be 1-32. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br i2c_reg: 0-255, the register to read. .br buf: an array to receive the read data. .br count: 1-32, the number of bytes to read. .br .EE .br .br Returns the number of bytes read (>0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED. .br .br .EX S Addr Wr [A] Comm [A] .br S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P .br .EE .IP "\fBint i2c_write_i2c_block_data(unsigned handle, unsigned i2c_reg, char *buf, unsigned count)\fP" .IP "" 4 This writes 1 to 32 bytes to the specified register of the device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br i2c_reg: 0-255, the register to write. .br buf: the data to write. .br count: 1-32, the number of bytes to write. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED. .br .br .EX S Addr Wr [A] Comm [A] Data [A] Data [A] ... [A] Data [A] P .br .EE .IP "\fBint i2c_read_device(unsigned handle, char *buf, unsigned count)\fP" .IP "" 4 This reads count bytes from the raw device into buf. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br buf: an array to receive the read data bytes. .br count: >0, the number of bytes to read. .br .EE .br .br Returns count (>0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED. .IP "\fBint i2c_write_device(unsigned handle, char *buf, unsigned count)\fP" .IP "" 4 This writes count bytes from buf to the raw device. .br .br .EX handle: >=0, as returned by a call to \fBi2c_open\fP. .br buf: an array containing the data bytes to write. .br count: >0, the number of bytes to write. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED. .IP "\fBint i2c_zip(unsigned handle, char *inBuf, unsigned inLen, char *outBuf, unsigned outLen)\fP" .IP "" 4 This function executes a sequence of I2C operations. The operations to be performed are specified by the contents of inBuf which contains the concatenated command codes and associated data. .br .br .EX handle: >=0, as returned by a call to \fBi2cOpen\fP .br inBuf: pointer to the concatenated I2C commands, see below .br inLen: size of command buffer .br outBuf: pointer to buffer to hold returned data .br outLen: size of output buffer .br .EE .br .br Returns >= 0 if OK (the number of bytes read), otherwise PI_BAD_HANDLE, PI_BAD_POINTER, PI_BAD_I2C_CMD, PI_BAD_I2C_RLEN. PI_BAD_I2C_WLEN, or PI_BAD_I2C_SEG. .br .br The following command codes are supported: .br .br Name Cmd & Data Meaning .br End 0 No more commands .br Escape 1 Next P is two bytes .br On 2 Switch combined flag on .br Off 3 Switch combined flag off .br Address 4 P Set I2C address to P .br Flags 5 lsb msb Set I2C flags to lsb + (msb << 8) .br Read 6 P Read P bytes of data .br Write 7 P ... Write P bytes of data .br .br .br The address, read, and write commands take a parameter P. Normally P is one byte (0-255). If the command is preceded by the Escape command then P is two bytes (0-65535, least significant byte first). .br .br The address defaults to that associated with the handle. The flags default to 0. The address and flags maintain their previous value until updated. .br .br The returned I2C data is stored in consecutive locations of outBuf. .br .br \fBExample\fP .br .EX Set address 0x53, write 0x32, read 6 bytes .br Set address 0x1E, write 0x03, read 6 bytes .br Set address 0x68, write 0x1B, read 8 bytes .br End .br .br 0x04 0x53 0x07 0x01 0x32 0x06 0x06 .br 0x04 0x1E 0x07 0x01 0x03 0x06 0x06 .br 0x04 0x68 0x07 0x01 0x1B 0x06 0x08 .br 0x00 .br .EE .br .br .IP "\fBint bb_i2c_open(unsigned SDA, unsigned SCL, unsigned baud)\fP" .IP "" 4 This function selects a pair of gpios for bit banging I2C at a specified baud rate. .br .br Bit banging I2C allows for certain operations which are not possible with the standard I2C driver. .br .br o baud rates as low as 50 .br o repeated starts .br o clock stretching .br o I2C on any pair of spare gpios .br .br .EX SDA: 0-31 .br SCL: 0-31 .br baud: 50-500000 .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_I2C_BAUD, or PI_GPIO_IN_USE. .br .br NOTE: .br .br The gpios used for SDA and SCL must have pull-ups to 3V3 connected. As a guide the hardware pull-ups on pins 3 and 5 are 1k8 in value. .IP "\fBint bb_i2c_close(unsigned SDA)\fP" .IP "" 4 This function stops bit banging I2C on a pair of gpios previously opened with \fBbb_i2c_open\fP. .br .br .EX SDA: 0-31, the SDA gpio used in a prior call to \fBbb_i2c_open\fP .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_USER_GPIO, or PI_NOT_I2C_GPIO. .IP "\fBint bb_i2c_zip(unsigned SDA, char *inBuf, unsigned inLen, char *outBuf, unsigned outLen)\fP" .IP "" 4 This function executes a sequence of bit banged I2C operations. The operations to be performed are specified by the contents of inBuf which contains the concatenated command codes and associated data. .br .br .EX SDA: 0-31 (as used in a prior call to \fBbb_i2c_open\fP) .br inBuf: pointer to the concatenated I2C commands, see below .br inLen: size of command buffer .br outBuf: pointer to buffer to hold returned data .br outLen: size of output buffer .br .EE .br .br Returns >= 0 if OK (the number of bytes read), otherwise PI_BAD_USER_GPIO, PI_NOT_I2C_GPIO, PI_BAD_POINTER, PI_BAD_I2C_CMD, PI_BAD_I2C_RLEN, PI_BAD_I2C_WLEN, PI_I2C_READ_FAILED, or PI_I2C_WRITE_FAILED. .br .br The following command codes are supported: .br .br Name Cmd & Data Meaning .br End 0 No more commands .br Escape 1 Next P is two bytes .br Start 2 Start condition .br Stop 3 Stop condition .br Address 4 P Set I2C address to P .br Flags 5 lsb msb Set I2C flags to lsb + (msb << 8) .br Read 6 P Read P bytes of data .br Write 7 P ... Write P bytes of data .br .br .br The address, read, and write commands take a parameter P. Normally P is one byte (0-255). If the command is preceded by the Escape command then P is two bytes (0-65535, least significant byte first). .br .br The address and flags default to 0. The address and flags maintain their previous value until updated. .br .br No flags are currently defined. .br .br The returned I2C data is stored in consecutive locations of outBuf. .br .br \fBExample\fP .br .EX Set address 0x53 .br start, write 0x32, (re)start, read 6 bytes, stop .br Set address 0x1E .br start, write 0x03, (re)start, read 6 bytes, stop .br Set address 0x68 .br start, write 0x1B, (re)start, read 8 bytes, stop .br End .br .br 0x04 0x53 .br 0x02 0x07 0x01 0x32 0x02 0x06 0x06 0x03 .br .br 0x04 0x1E .br 0x02 0x07 0x01 0x03 0x02 0x06 0x06 0x03 .br .br 0x04 0x68 .br 0x02 0x07 0x01 0x1B 0x02 0x06 0x08 0x03 .br .br 0x00 .br .EE .IP "\fBint spi_open(unsigned spi_channel, unsigned baud, unsigned spi_flags)\fP" .IP "" 4 This function returns a handle for the SPI device on channel. Data will be transferred at baud bits per second. The flags may be used to modify the default behaviour of 4-wire operation, mode 0, active low chip select. .br .br An auxiliary SPI device is available on the A+/B+/Pi2 and may be selected by setting the A bit in the flags. The auxiliary device has 3 chip selects and a selectable word size in bits. .br .br .EX spi_channel: 0-1 (0-2 for A+/B+/Pi2 auxiliary device). .br baud: 32K-125M (values above 30M are unlikely to work). .br spi_flags: see below. .br .EE .br .br Returns a handle (>=0) if OK, otherwise PI_BAD_SPI_CHANNEL, PI_BAD_SPI_SPEED, PI_BAD_FLAGS, PI_NO_AUX_SPI, or PI_SPI_OPEN_FAILED. .br .br spi_flags consists of the least significant 22 bits. .br .br .EX 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 .br b b b b b b R T n n n n W A u2 u1 u0 p2 p1 p0 m m .br .EE .br .br mm defines the SPI mode. .br .br Warning: modes 1 and 3 do not appear to work on the auxiliary device. .br .br .EX Mode POL PHA .br 0 0 0 .br 1 0 1 .br 2 1 0 .br 3 1 1 .br .EE .br .br px is 0 if CEx is active low (default) and 1 for active high. .br .br ux is 0 if the CEx gpio is reserved for SPI (default) and 1 otherwise. .br .br A is 0 for the standard SPI device, 1 for the auxiliary SPI. The auxiliary device is only present on the A+/B+/Pi2. .br .br W is 0 if the device is not 3-wire, 1 if the device is 3-wire. Standard SPI device only. .br .br nnnn defines the number of bytes (0-15) to write before switching the MOSI line to MISO to read data. This field is ignored if W is not set. Standard SPI device only. .br .br T is 1 if the least significant bit is transmitted on MOSI first, the default (0) shifts the most significant bit out first. Auxiliary SPI device only. .br .br R is 1 if the least significant bit is received on MISO first, the default (0) receives the most significant bit first. Auxiliary SPI device only. .br .br bbbbbb defines the word size in bits (0-32). The default (0) sets 8 bits per word. Auxiliary SPI device only. .br .br The other bits in flags should be set to zero. .IP "\fBint spi_close(unsigned handle)\fP" .IP "" 4 This functions closes the SPI device identified by the handle. .br .br .EX handle: >=0, as returned by a call to \fBspi_open\fP. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE. .IP "\fBint spi_read(unsigned handle, char *buf, unsigned count)\fP" .IP "" 4 This function reads count bytes of data from the SPI device associated with the handle. .br .br .EX handle: >=0, as returned by a call to \fBspi_open\fP. .br buf: an array to receive the read data bytes. .br count: the number of bytes to read. .br .EE .br .br Returns the number of bytes transferred if OK, otherwise PI_BAD_HANDLE, PI_BAD_SPI_COUNT, or PI_SPI_XFER_FAILED. .IP "\fBint spi_write(unsigned handle, char *buf, unsigned count)\fP" .IP "" 4 This function writes count bytes of data from buf to the SPI device associated with the handle. .br .br .EX handle: >=0, as returned by a call to \fBspi_open\fP. .br buf: the data bytes to write. .br count: the number of bytes to write. .br .EE .br .br Returns the number of bytes transferred if OK, otherwise PI_BAD_HANDLE, PI_BAD_SPI_COUNT, or PI_SPI_XFER_FAILED. .IP "\fBint spi_xfer(unsigned handle, char *txBuf, char *rxBuf, unsigned count)\fP" .IP "" 4 This function transfers count bytes of data from txBuf to the SPI device associated with the handle. Simultaneously count bytes of data are read from the device and placed in rxBuf. .br .br .EX handle: >=0, as returned by a call to \fBspi_open\fP. .br txBuf: the data bytes to write. .br rxBuf: the received data bytes. .br count: the number of bytes to transfer. .br .EE .br .br Returns the number of bytes transferred if OK, otherwise PI_BAD_HANDLE, PI_BAD_SPI_COUNT, or PI_SPI_XFER_FAILED. .IP "\fBint serial_open(char *ser_tty, unsigned baud, unsigned ser_flags)\fP" .IP "" 4 This function opens a serial device at a specified baud rate with specified flags. .br .br .EX ser_tty: the serial device to open, /dev/tty*. .br baud: the baud rate in bits per second, see below. .br ser_flags: 0. .br .EE .br .br Returns a handle (>=0) if OK, otherwise PI_NO_HANDLE, or PI_SER_OPEN_FAILED. .br .br The baud rate must be one of 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200, or 230400. .br .br No flags are currently defined. This parameter should be set to zero. .IP "\fBint serial_close(unsigned handle)\fP" .IP "" 4 This function closes the serial device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBserial_open\fP. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE. .IP "\fBint serial_write_byte(unsigned handle, unsigned bVal)\fP" .IP "" 4 This function writes bVal to the serial port associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBserial_open\fP. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_SER_WRITE_FAILED. .IP "\fBint serial_read_byte(unsigned handle)\fP" .IP "" 4 This function reads a byte from the serial port associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBserial_open\fP. .br .EE .br .br Returns the read byte (>=0) if OK, otherwise PI_BAD_HANDLE, PI_SER_READ_NO_DATA, or PI_SER_READ_FAILED. .IP "\fBint serial_write(unsigned handle, char *buf, unsigned count)\fP" .IP "" 4 This function writes count bytes from buf to the the serial port associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBserial_open\fP. .br buf: the array of bytes to write. .br count: the number of bytes to write. .br .EE .br .br Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_SER_WRITE_FAILED. .IP "\fBint serial_read(unsigned handle, char *buf, unsigned count)\fP" .IP "" 4 This function reads up to count bytes from the the serial port associated with handle and writes them to buf. .br .br .EX handle: >=0, as returned by a call to \fBserial_open\fP. .br buf: an array to receive the read data. .br count: the maximum number of bytes to read. .br .EE .br .br Returns the number of bytes read (>0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, PI_SER_READ_NO_DATA, or PI_SER_WRITE_FAILED. .IP "\fBint serial_data_available(unsigned handle)\fP" .IP "" 4 Returns the number of bytes available to be read from the device associated with handle. .br .br .EX handle: >=0, as returned by a call to \fBserial_open\fP. .br .EE .br .br Returns the number of bytes of data available (>=0) if OK, otherwise PI_BAD_HANDLE. .IP "\fBint custom_1(unsigned arg1, unsigned arg2, char *argx, unsigned argc)\fP" .IP "" 4 This function is available for user customisation. .br .br It returns a single integer value. .br .br .EX arg1: >=0 .br arg2: >=0 .br argx: extra (byte) arguments .br argc: number of extra arguments .br .EE .br .br Returns >= 0 if OK, less than 0 indicates a user defined error. .IP "\fBint custom_2(unsigned arg1, char *argx, unsigned argc, char *retBuf, unsigned retMax)\fP" .IP "" 4 This function is available for user customisation. .br .br It differs from custom_1 in that it returns an array of bytes rather than just an integer. .br .br The return value is an integer indicating the number of returned bytes. .EX arg1: >=0 .br argc: extra (byte) arguments .br count: number of extra arguments .br retBuf: buffer for returned data .br retMax: maximum number of bytes to return .br .EE .br .br Returns >= 0 if OK, less than 0 indicates a user defined error. .br .br Note, the number of returned bytes will be retMax or less. .IP "\fBint callback(unsigned user_gpio, unsigned edge, CBFunc_t f)\fP" .IP "" 4 This function initialises a new callback. .br .br .EX user_gpio: 0-31. .br edge: RISING_EDGE, FALLING_EDGE, or EITHER_EDGE. .br f: the callback function. .br .EE .br .br The function returns a callback id if OK, otherwise pigif_bad_malloc, pigif_duplicate_callback, or pigif_bad_callback. .br .br The callback is called with the gpio, edge, and tick, whenever the gpio has the identified edge. .IP "\fBint callback_ex(unsigned user_gpio, unsigned edge, CBFuncEx_t f, void *userdata)\fP" .IP "" 4 This function initialises a new callback. .br .br .EX user_gpio: 0-31. .br edge: RISING_EDGE, FALLING_EDGE, or EITHER_EDGE. .br f: the callback function. .br userdata: a pointer to arbitrary user data. .br .EE .br .br The function returns a callback id if OK, otherwise pigif_bad_malloc, pigif_duplicate_callback, or pigif_bad_callback. .br .br The callback is called with the gpio, edge, tick, and user, whenever the gpio has the identified edge. .br .br .IP "\fBint callback_cancel(unsigned callback_id)\fP" .IP "" 4 This function cancels a callback identified by its id. .br .br .EX callback_id: >=0, as returned by a call to \fBcallback\fP or \fBcallback_ex\fP. .br .EE .br .br The function returns 0 if OK, otherwise pigif_callback_not_found. .IP "\fBint wait_for_edge(unsigned user_gpio, unsigned edge, double timeout)\fP" .IP "" 4 This function waits for edge on the gpio for up to timeout seconds. .br .br .EX user_gpio: 0-31. .br edge: RISING_EDGE, FALLING_EDGE, or EITHER_EDGE. .br timeout: >=0. .br .EE .br .br The function returns 1 if the edge occurred, otherwise 0. .br .br The function returns when the edge occurs or after the timeout. .SH PARAMETERS .br .br .IP "\fBactive\fP: 0-1000000" 0 .br .br The number of microseconds level changes are reported for once a noise filter has been triggered (by \fBsteady\fP microseconds of a stable level). .br .br .IP "\fB*addrStr\fP" 0 A string specifying the host or IP address of the Pi running the pigpio daemon. It may be NULL in which case localhost is used unless overridden by the PIGPIO_ADDR environment variable. .br .br .IP "\fBarg1\fP" 0 An unsigned argument passed to a user customised function. Its meaning is defined by the customiser. .br .br .IP "\fBarg2\fP" 0 An unsigned argument passed to a user customised function. Its meaning is defined by the customiser. .br .br .IP "\fBargc\fP" 0 The count of bytes passed to a user customised function. .br .br .IP "\fB*argx\fP" 0 A pointer to an array of bytes passed to a user customised function. Its meaning and content is defined by the customiser. .br .br .IP "\fBbaud\fP" 0 The speed of serial communication (I2C, SPI, serial link, waves) in bits per second. .br .br .IP "\fBbit\fP" 0 A value of 0 or 1. .br .br .IP "\fBbits\fP" 0 A value used to select gpios. If bit n of bits is set then gpio n is selected. .br .br A convenient way to set bit n is to or in (1<=0, as returned by a call to \fBcallback\fP or \fBcallback_ex\fP. This is passed to \fBcallback_cancel\fP to cancel the callback. .br .br .IP "\fBCBFunc_t\fP" 0 .EX typedef void (*CBFunc_t) .br (unsigned user_gpio, unsigned level, uint32_t tick); .br .EE .br .br .IP "\fBCBFuncEx_t\fP" 0 .EX typedef void (*CBFuncEx_t) .br (unsigned user_gpio, unsigned level, uint32_t tick, void * user); .br .EE .br .br .IP "\fBchar\fP" 0 A single character, an 8 bit quantity able to store 0-255. .br .br .IP "\fBclkfreq\fP: 4689-250000000 (250M)" 0 The hardware clock frequency. .br .br .IP "\fBcount\fP" 0 The number of bytes to be transferred in an I2C, SPI, or Serial command. .br .br .IP "\fBdata_bits\fP: 1-32" 0 The number of data bits in each character of serial data. .br .br .EX #define PI_MIN_WAVE_DATABITS 1 .br #define PI_MAX_WAVE_DATABITS 32 .br .EE .br .br .IP "\fBdouble\fP" 0 A floating point number. .br .br .IP "\fBdutycycle\fP: 0-range" 0 A number representing the ratio of on time to off time for PWM. .br .br The number may vary between 0 and range (default 255) where 0 is off and range is fully on. .br .br .IP "\fBedge\fP" 0 Used to identify a gpio level transition of interest. A rising edge is a level change from 0 to 1. A falling edge is a level change from 1 to 0. .br .br .EX RISING_EDGE 0 .br FALLING_EDGE 1 .br EITHER_EDGE. 2 .br .EE .br .br .IP "\fBerrnum\fP" 0 A negative number indicating a function call failed and the nature of the error. .br .br .IP "\fBf\fP" 0 A function. .br .br .IP "\fBfrequency\fP: 0-" 0 The number of times a gpio is swiched on and off per second. This can be set per gpio and may be as little as 5Hz or as much as 40KHz. The gpio will be on for a proportion of the time as defined by its dutycycle. .br .br .br .br .IP "\fBgpio\fP" 0 A Broadcom numbered gpio, in the range 0-53. .br .br There are 54 General Purpose Input Outputs (gpios) named gpio0 through gpio53. .br .br They are split into two banks. Bank 1 consists of gpio0 through gpio31. Bank 2 consists of gpio32 through gpio53. .br .br All the gpios which are safe for the user to read and write are in bank 1. Not all gpios in bank 1 are safe though. Type 1 boards have 17 safe gpios. Type 2 boards have 21. Type 3 boards have 26. .br .br See \fBget_hardware_revision\fP. .br .br The user gpios are marked with an X in the following table. .br .br .EX 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 .br Type 1 X X - - X - - X X X X X - - X X .br Type 2 - - X X X - - X X X X X - - X X .br Type 3 X X X X X X X X X X X X X X .br .br 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 .br Type 1 - X X - - X X X X X - - - - - - .br Type 2 - X X - - - X X X X - X X X X X .br Type 3 X X X X X X X X X X X X - - - - .br .EE .br .br .IP "\fBgpioPulse_t\fP" 0 .EX typedef struct .br { .br uint32_t gpioOn; .br uint32_t gpioOff; .br uint32_t usDelay; .br } gpioPulse_t; .br .EE .br .br .IP "\fBgpioThreadFunc_t\fP" 0 .EX typedef void *(gpioThreadFunc_t) (void *); .br .EE .br .br .IP "\fBhandle\fP: 0-" 0 A number referencing an object opened by one of \fBi2c_open\fP, \fBnotify_open\fP, \fBserial_open\fP, and \fBspi_open\fP. .br .br .IP "\fBi2c_addr\fP" 0 The address of a device on the I2C bus. .br .br .IP "\fBi2c_bus\fP: 0-1" 0 An I2C bus, 0 or 1. .br .br .IP "\fBi2c_flags\fP: 0" 0 Flags which modify an I2C open command. None are currently defined. .br .br .IP "\fBi2c_reg\fP: 0-255" 0 A register of an I2C device. .br .br .IP "\fB*inBuf\fP" 0 A buffer used to pass data to a function. .br .br .IP "\fBinLen\fP" 0 The number of bytes of data in a buffer. .br .br .IP "\fBint\fP" 0 A whole number, negative or positive. .br .br .IP "\fBinvert\fP" 0 A flag used to set normal or inverted bit bang serial data level logic. .br .br .IP "\fBlevel\fP" 0 The level of a gpio. Low or High. .br .br .EX PI_OFF 0 .br PI_ON 1 .br .br PI_CLEAR 0 .br PI_SET 1 .br .br PI_LOW 0 .br PI_HIGH 1 .br .EE .br .br There is one exception. If a watchdog expires on a gpio the level will be reported as PI_TIMEOUT. See \fBset_watchdog\fP. .br .br .EX PI_TIMEOUT 2 .br .EE .br .br .IP "\fBmode\fP: 0-7" 0 The operational mode of a gpio, normally INPUT or OUTPUT. .br .br .EX PI_INPUT 0 .br PI_OUTPUT 1 .br PI_ALT0 4 .br PI_ALT1 5 .br PI_ALT2 6 .br PI_ALT3 7 .br PI_ALT4 3 .br PI_ALT5 2 .br .EE .br .br .IP "\fBnumBytes\fP" 0 The number of bytes used to store characters in a string. Depending on the number of bits per character there may be 1, 2, or 4 bytes per character. .br .br .IP "\fBnumPar\fP: 0-10" 0 The number of parameters passed to a script. .br .br .IP "\fBnumPulses\fP" 0 The number of pulses to be added to a waveform. .br .br .IP "\fBoffset\fP" 0 The associated data starts this number of microseconds from the start of the waveform. .br .br .IP "\fB*outBuf\fP" 0 A buffer used to return data from a function. .br .br .IP "\fBoutLen\fP" 0 The size in bytes of an output buffer. .br .br .IP "\fB*param\fP" 0 An array of script parameters. .br .br .IP "\fB*portStr\fP" 0 A string specifying the port address used by the Pi running the pigpio daemon. It may be NULL in which case "8888" is used unless overridden by the PIGPIO_PORT environment variable. .br .br .IP "\fB*pth\fP" 0 A thread identifier, returned by \fBstart_thread\fP. .br .br .br .br .IP "\fBpthread_t\fP" 0 A thread identifier. .br .br .IP "\fBpud\fP: 0-2" 0 The setting of the pull up/down resistor for a gpio, which may be off, pull-up, or pull-down. .EX PI_PUD_OFF 0 .br PI_PUD_DOWN 1 .br PI_PUD_UP 2 .br .EE .br .br .IP "\fBpulseLen\fP" 0 1-100, the length of a trigger pulse in microseconds. .br .br .IP "\fB*pulses\fP" 0 An array of pulses to be added to a waveform. .br .br .IP "\fBpulsewidth\fP: 0, 500-2500" 0 .EX PI_SERVO_OFF 0 .br PI_MIN_SERVO_PULSEWIDTH 500 .br PI_MAX_SERVO_PULSEWIDTH 2500 .br .EE .br .br .IP "\fBPWMduty\fP: 0-1000000 (1M)" 0 The hardware PWM dutycycle. .br .br .EX #define PI_HW_PWM_RANGE 1000000 .br .EE .br .br .IP "\fBPWMfreq\fP: 1-125000000 (125M)" 0 The hardware PWM frequency. .br .br .EX #define PI_HW_PWM_MIN_FREQ 1 .br #define PI_HW_PWM_MAX_FREQ 125000000 .br .EE .br .br .IP "\fBrange\fP: 25-40000" 0 The permissible dutycycle values are 0-range. .EX PI_MIN_DUTYCYCLE_RANGE 25 .br PI_MAX_DUTYCYCLE_RANGE 40000 .br .EE .br .br .IP "\fB*retBuf\fP" 0 A buffer to hold a number of bytes returned to a used customised function, .br .br .IP "\fBretMax\fP" 0 The maximum number of bytes a user customised function should return. .br .br .br .br .IP "\fB*rxBuf\fP" 0 A pointer to a buffer to receive data. .br .br .IP "\fBSCL\fP" 0 The user gpio to use for the clock when bit banging I2C. .br .br .IP "\fB*script\fP" 0 A pointer to the text of a script. .br .br .IP "\fBscript_id\fP" 0 An id of a stored script as returned by \fBstore_script\fP. .br .br .IP "\fBSDA\fP" 0 The user gpio to use for data when bit banging I2C. .br .br .IP "\fBseconds\fP" 0 The number of seconds. .br .br .IP "\fBser_flags\fP" 0 Flags which modify a serial open command. None are currently defined. .br .br .IP "\fB*ser_tty\fP" 0 The name of a serial tty device, e.g. /dev/ttyAMA0, /dev/ttyUSB0, /dev/tty1. .br .br .IP "\fBsize_t\fP" 0 A standard type used to indicate the size of an object in bytes. .br .br .IP "\fBspi_channel\fP" 0 A SPI channel, 0-2. .br .br .IP "\fBspi_flags\fP" 0 See \fBspi_open\fP. .br .br .IP "\fBsteady\fP: 0-300000" 0 .br .br The number of microseconds level changes must be stable for before reporting the level changed (\fBset_glitch_filter\fP) or triggering the active part of a noise filter (\fBset_noise_filter\fP). .br .br .IP "\fBstop_bits\fP: 2-8" 0 The number of (half) stop bits to be used when adding serial data to a waveform. .br .br .EX #define PI_MIN_WAVE_HALFSTOPBITS 2 .br #define PI_MAX_WAVE_HALFSTOPBITS 8 .br .EE .br .br .IP "\fB*str\fP" 0 An array of characters. .br .br .IP "\fBthread_func\fP" 0 A function of type gpioThreadFunc_t used as the main function of a thread. .br .br .IP "\fBtimeout\fP" 0 A gpio watchdog timeout in milliseconds. .EX PI_MIN_WDOG_TIMEOUT 0 .br PI_MAX_WDOG_TIMEOUT 60000 .br .EE .br .br .IP "\fB*txBuf\fP" 0 An array of bytes to transmit. .br .br .IP "\fBuint32_t\fP: 0-0-4,294,967,295 (Hex 0x0-0xFFFFFFFF)" 0 A 32-bit unsigned value. .br .br .IP "\fBunsigned\fP" 0 A whole number >= 0. .br .br .IP "\fBuser_gpio\fP" 0 0-31, a Broadcom numbered gpio. .br .br See \fBgpio\fP. .br .br .IP "\fB*userdata\fP" 0 A pointer to arbitrary user data. This may be used to identify the instance. .br .br .IP "\fBvoid\fP" 0 Denoting no parameter is required .br .br .IP "\fBwave_add_*\fP" 0 One of \fBwave_add_new\fP, \fBwave_add_generic\fP, \fBwave_add_serial\fP. .br .br .IP "\fBwave_id\fP" 0 A number representing a waveform created by \fBwave_create\fP. .br .br .IP "\fBwave_send_*\fP" 0 One of \fBwave_send_once\fP, \fBwave_send_repeat\fP. .br .br .IP "\fBwVal\fP: 0-65535 (Hex 0x0-0xFFFF, Octal 0-0177777)" 0 A 16-bit word value. .br .br .SH pigpiod_if Error Codes .EX .br typedef enum .br { .br pigif_bad_send = -2000, .br pigif_bad_recv = -2001, .br pigif_bad_getaddrinfo = -2002, .br pigif_bad_connect = -2003, .br pigif_bad_socket = -2004, .br pigif_bad_noib = -2005, .br pigif_duplicate_callback = -2006, .br pigif_bad_malloc = -2007, .br pigif_bad_callback = -2008, .br pigif_notify_failed = -2009, .br pigif_callback_not_found = -2010, .br } pigifError_t; .br .br .EE .SH SEE ALSO pigpiod(1), pig2vcd(1), pigs(1), pigpio(3), pigpiod_if2(3) .SH AUTHOR joan@abyz.co.uk