pigpio/pigpiod_if.3

." Process this file with
." groff -man -Tascii pigpiod_if.3
."
.TH pigpiod_if 3 2012-2014 Linux "pigpio archive"
.SH NAME
pigpiod_if - A C library to interface to the pigpio daemon.

.SH SYNOPSIS

gcc -o prog prog.c -lpigpiod_if

 ./prog
.SH DESCRIPTION


.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

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o callbacks when any of gpios 0-31 change state

.br

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o callbacks at timed intervals

.br

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o reading/writing all of the gpios in a bank as one operation

.br

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o individually setting gpio modes, reading and writing

.br

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o notifications when any of gpios 0-31 change state

.br

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o the construction of output waveforms with microsecond timing

.br

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o rudimentary permission control over gpios

.br

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o a simple interface to start and stop new threads

.br

.br
o I2C, SPI, and serial link wrappers

.br

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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 <pigpiod_if.h> in your source files.

.br

.br
Assuming your source is in prog.c use the following command to build

.br

.br

.EX
gcc -o prog prog.c -lpigpiod_if
.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

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.EX
thread_func: the main function for the new thread.
.br
   userdata: a pointer to an arbitrary argument.
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.EE

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Returns a pointer to pthread_t if OK, otherwise NULL.

.br

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The function is passed the single argument userdata.

.br

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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

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.EX
pth: the thread to be stopped.
.br

.EE

.br

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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

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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).  If a hardware clock is
active on the gpio the reported dutycycle will be 500 (out of 1000).
If hardware PWM is active on the gpio the reported dutycycle
will be out of a 1000.

.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

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.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 1000.

.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 or hardware PWM is active on the gpio the
reported real range will be 1000.

.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

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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

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.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.  If a hardware clock is active on the gpio the
reported frequency will be that set by \fBhardware_clock\fP.  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

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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.

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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.

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.br
You can DAMAGE a servo if you command it to move beyond its limits.

.br

.br
OTHER UPDATE RATES:

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This function updates servos at 50Hz.  If you wish to use a different
update frequency you will have to use the PWM functions.

.br

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.EX
Update Rate (Hz)     50   100  200  400  500
.br
1E6/Hz            20000 10000 5000 2500 2000
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.EE

.br

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Firstly set the desired PWM frequency using \fBset_PWM_frequency\fP.

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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.

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E.g. If you want to update a servo connected to gpio 25 at 400Hz

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.EX
set_PWM_frequency(25, 400);
.br
set_PWM_range(25, 2500);
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.EE

.br

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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

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.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

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.EX
handle: 0-31 (as returned by \fBnotify_open\fP)
.br

.EE

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.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

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.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

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Only one watchdog may be registered per gpio.

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The watchdog may be cancelled by setting timeout to 0.

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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.

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.br
The \fBcallback\fP and \fBcallback_ex\fP functions interpret the flags
and will call registered callbacks for the gpio with level TIMEOUT.

.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<<n).

.IP "\fBuint32_t read_bank_2(void)\fP"
.IP "" 4
Read the levels of the bank 2 gpios (gpios 32-53).

.br

.br
The returned 32 bit integer has a bit set if the corresponding
gpio is logic 1.  Gpio n has bit value (1<<(n-32)).

.IP "\fBint clear_bank_1(uint32_t bits)\fP"
.IP "" 4
Clears gpios 0-31 if the corresponding bit in bits is set.

.br

.br

.EX
bits: a bit mask with 1 set if the corresponding gpio is
.br
      to be cleared.
.br

.EE

.br

.br
Returns 0 if OK, otherwise PI_SOME_PERMITTED.

.br

.br
A status of PI_SOME_PERMITTED indicates that the user is not
allowed to write to one or more of the gpios.

.IP "\fBint clear_bank_2(uint32_t bits)\fP"
.IP "" 4
Clears gpios 32-53 if the corresponding bit (0-21) in bits is set.

.br

.br

.EX
bits: a bit mask with 1 set if the corresponding gpio is
.br
      to be cleared.
.br

.EE

.br

.br
Returns 0 if OK, otherwise PI_SOME_PERMITTED.

.br

.br
A status of PI_SOME_PERMITTED indicates that the user is not
allowed to write to one or more of the gpios.

.IP "\fBint set_bank_1(uint32_t bits)\fP"
.IP "" 4
Sets gpios 0-31 if the corresponding bit in bits is set.

.br

.br

.EX
bits: a bit mask with 1 set if the corresponding gpio is
.br
      to be set.
.br

.EE

.br

.br
Returns 0 if OK, otherwise PI_SOME_PERMITTED.

.br

.br
A status of PI_SOME_PERMITTED indicates that the user is not
allowed to write to one or more of the gpios.

.IP "\fBint set_bank_2(uint32_t bits)\fP"
.IP "" 4
Sets gpios 32-53 if the corresponding bit (0-21) in bits is set.

.br

.br

.EX
bits: a bit mask with 1 set if the corresponding gpio is
.br
      to be set.
.br

.EE

.br

.br
Returns 0 if OK, otherwise PI_SOME_PERMITTED.

.br

.br
A status of PI_SOME_PERMITTED indicates that the user is not
allowed to write to one or more of the gpios.

.IP "\fBint hardware_clock(unsigned gpio, unsigned clkfreq)\fP"
.IP "" 4
Starts a hardware clock on a gpio at the specified frequency.

.br

.br

.EX
     gpio: see description
.br
frequency: 0 (off) or 4689-250M
.br

.EE

.br

.br
Returns 0 if OK, otherwise PI_NOT_PERMITTED, PI_BAD_GPIO,
PI_NOT_HCLK_GPIO, PI_BAD_HCLK_FREQ,or PI_BAD_HCLK_PASS.

.br

.br
The same clock is available on multiple gpios.  The latest
frequency setting will be used by all gpios which share a clock.

.br

.br
The gpio must be one of the following.

.br

.br

.EX
4   clock 0  All models
.br
5   clock 1  A+/B+ and compute module only (reserved for system use)
.br
6   clock 2  A+/B+ and compute module only
.br
20  clock 0  A+/B+ and compute module only
.br
21  clock 1  All models but Rev.2 B (reserved for system use)
.br

.br
32  clock 0  Compute module only
.br
34  clock 0  Compute module only
.br
42  clock 1  Compute module only (reserved for system use)
.br
43  clock 2  Compute module only
.br
44  clock 1  Compute module only (reserved for system use)
.br

.EE

.br

.br
Access to clock 1 is protected by a password as its use will likely
crash the Pi.  The password is given by or'ing 0x5A000000 with the
gpio number.

.IP "\fBint hardware_PWM(unsigned gpio, unsigned PWMfreq, uint32_t PWMduty)\fP"
.IP "" 4
Starts hardware PWM on a gpio at the specified frequency and dutycycle.

.br

.br
NOTE: Any waveform started by \fBwave_send_once\fP, \fBwave_send_repeat\fP, \fBwave_tx_start\fP, or \fBwave_tx_repeat\fP will be cancelled.

.br

.br
This function is only valid if the pigpio main clock is PCM.  The
main clock defaults to PCM but may be overridden when the pigpio
daemon is started (option -t).

.br

.br

.EX
   gpio: see descripton
.br
PWMfreq: 0 (off) or 5-50K
.br
PWMduty: 0 (off) to 5000 (fully on).
.br

.EE

.br

.br
Returns 0 if OK, otherwise PI_NOT_PERMITTED, PI_BAD_GPIO,
PI_NOT_HPWM_GPIO, PI_BAD_HPWM_DUTY, PI_BAD_HPWM_FREQ,
or PI_HPWM_ILLEGAL.

.br

.br
Both PWM channels share the same clock and the same update frequency.
The latest frequency setting will be used by both PWM channels. The
same PWM channel is available on multiple gpios.  The latest
dutycycle setting will be used by all gpios which share a PWM channel.

.br

.br
The gpio must be one of the following.

.br

.br

.EX
12  PWM channel 0  A+/B+ and compute module only
.br
13  PWM channel 1  A+/B+ and compute module only
.br
18  PWM channel 0  All models
.br
19  PWM channel 1  A+/B+ and compute module only
.br

.br
40  PWM channel 0  Compute module only
.br
41  PWM channel 1  Compute module only
.br
45  PWM channel 1  Compute module only
.br
52  PWM channel 0  Compute module only
.br
53  PWM channel 1  Compute module only
.br

.EE

.IP "\fBuint32_t get_current_tick(void)\fP"
.IP "" 4
Gets the current system tick.

.br

.br
Tick is the number of microseconds since system boot.

.br

.br
As tick is an unsigned 32 bit quantity it wraps around after
2**32 microseconds, which is approximately 1 hour 12 minutes.

.br

.br

.IP "\fBuint32_t get_hardware_revision(void)\fP"
.IP "" 4
Get the Pi's hardware revision number.

.br

.br
The hardware revision is the last 4 characters on the Revision line
of /proc/cpuinfo.

.br

.br
If the hardware revision can not be found or is not a valid
hexadecimal number the function returns 0.

.br

.br
The revision number can be used to determine the assignment of gpios
to pins.

.br

.br
There are currently three types of board.

.br

.br
Type 1 has gpio 0 on P1-3, gpio 1 on P1-5, and gpio 21 on P1-13.

.br

.br
Type 2 has gpio 2 on P1-3, gpio 3 on P1-5, gpio 27 on P1-13, and
gpios 28-31 on P5.

.br

.br
Type 3 has a 40 pin connector rather than the 26 pin connector of
the earlier boards. Gpios 0 to 27 are brought out to the connector.

.br

.br
Type 1 boards have hardware revision numbers of 2 and 3.

.br

.br
Type 2 boards have hardware revision numbers of 4, 5, 6, and 15.

.br

.br
Type 3 boards have hardware revision number 16.

.IP "\fBuint32_t get_pigpio_version(void)\fP"
.IP "" 4
Returns the pigpio version.

.IP "\fBint wave_clear(void)\fP"
.IP "" 4
This function clears all waveforms and any data added by calls to the
\fBwave_add_*\fP functions.

.br

.br
Returns 0 if OK.

.IP "\fBint wave_add_new(void)\fP"
.IP "" 4
This function starts a new empty waveform.  You wouldn't normally need
to call this function as it is automatically called after a waveform is
created with the \fBwave_create\fP function.

.br

.br
Returns 0 if OK.

.IP "\fBint wave_add_generic(unsigned numPulses, gpioPulse_t *pulses)\fP"
.IP "" 4
This function adds a number of pulses to the current waveform.

.br

.br

.EX
numPulses: the number of pulses.
.br
   pulses: an array of pulses.
.br

.EE

.br

.br
Returns the new total number of pulses in the current waveform if OK,
otherwise PI_TOO_MANY_PULSES.

.br

.br
The pulses are interleaved in time order within the existing waveform
(if any).

.br

.br
Merging allows the waveform to be built in parts, that is the settings
for gpio#1 can be added, and then gpio#2 etc.

.br

.br
If the added waveform is intended to start after or within the existing
waveform then the first pulse should consist solely of a delay.

.IP "\fBint wave_add_serial(unsigned user_gpio, unsigned bbBaud, unsigned bbBits, unsigned bbStop, unsigned offset, unsigned numBytes, char *str)\fP"
.IP "" 4
This function adds a waveform representing serial data to the
existing waveform (if any).  The serial data starts offset
microseconds from the start of the waveform.

.br

.br

.EX
user_gpio: 0-31.
.br
   bbBaud: 100-250000
.br
   bbBits: number of data bits (1-32)
.br
   bbStop: number of stop half bits (2-8)
.br
   offset: 0-
.br
 numBytes: 1-
.br
      str: an array of chars.
.br

.EE

.br

.br
Returns the new total number of pulses in the current waveform if OK,
otherwise PI_BAD_USER_GPIO, PI_BAD_WAVE_BAUD, PI_BAD_DATABITS,
PI_BAD_STOP_BITS, PI_TOO_MANY_CHARS, PI_BAD_SER_OFFSET,
or PI_TOO_MANY_PULSES.

.br

.br
NOTES:

.br

.br
The serial data is formatted as one start bit, \fBbbBits\fP data bits,
and \fBbbStop\fP/2 stop bits.

.br

.br
It is legal to add serial data streams with different baud rates to
the same waveform.

.br

.br
\fBnumBytes\fP is the number of bytes of data in str.

.br

.br
The bytes required for each character depend upon \fBbbBits\fP.

.br

.br
For \fBbbBits\fP 1-8 there will be one byte per character.
.br
For \fBbbBits\fP 9-16 there will be two bytes per character.
.br
For \fBbbBits\fP 17-32 there will be four bytes per character.

.IP "\fBint wave_create(void)\fP"
.IP "" 4
This function creates a waveform from the data provided by the prior
calls to the \fBwave_add_*\fP functions.  Upon success a positive wave id
is returned.

.br

.br
The data provided by the \fBwave_add_*\fP functions is consumed by this
function.

.br

.br
As many waveforms may be created as there is space available.  The
wave id is passed to \fBwave_send_*\fP to specify the waveform to transmit.

.br

.br
Normal usage would be

.br

.br
Step 1. \fBwave_clear\fP to clear all waveforms and added data.

.br

.br
Step 2. \fBwave_add_*\fP calls to supply the waveform data.

.br

.br
Step 3. \fBwave_create\fP to create the waveform and get a unique id

.br

.br
Repeat steps 2 and 3 as needed.

.br

.br
Step 4. \fBwave_send_*\fP with the id of the waveform to transmit.

.br

.br
A waveform comprises one or more pulses.  Each pulse consists of a
\fBgpioPulse_t\fP structure.

.br

.br

.EX
typedef struct
.br
{
.br
   uint32_t gpioOn;
.br
   uint32_t gpioOff;
.br
   uint32_t usDelay;
.br
} gpioPulse_t;
.br

.EE

.br

.br
The fields specify

.br

.br
1) the gpios to be switched on at the start of the pulse.
.br
2) the gpios to be switched off at the start of the pulse.
.br
3) the delay in microseconds before the next pulse.
.br

.br

.br
Any or all the fields can be zero.  It doesn't make any sense to
set all the fields to zero (the pulse will be ignored).

.br

.br
When a waveform is started each pulse is executed in order with the
specified delay between the pulse and the next.

.br

.br
Returns the new waveform id if OK, otherwise PI_EMPTY_WAVEFORM,
PI_NO_WAVEFORM_ID, PI_TOO_MANY_CBS, or PI_TOO_MANY_OOL.

.IP "\fBint wave_delete(unsigned wave_id)\fP"
.IP "" 4
This function deletes all created waveforms with ids greater than or
equal to wave_id.

.br

.br

.EX
wave_id: >=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_tx_start(void)\fP"
.IP "" 4
This function is deprecated and should no longer be used.

.br

.br
Use \fBwave_create\fP/\fBwave_send_*\fP instead.

.br

.br
NOTE: Any hardware PWM started by \fBhardware_PWM\fP will be cancelled.

.IP "\fBint wave_tx_repeat(void)\fP"
.IP "" 4
This function is deprecated and should no longer be used.

.br

.br
Use \fBwave_create\fP/\fBwave_send_*\fP instead.

.br

.br
NOTE: Any hardware PWM started by \fBhardware_PWM\fP will be cancelled.

.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_tx_busy(void)\fP"
.IP "" 4
This function checks to see if a waveform is currently being
transmitted.

.br

.br
Returns 1 if a waveform is currently being transmitted, otherwise 0.

.IP "\fBint wave_tx_stop(void)\fP"
.IP "" 4
This function stops the transmission of the current waveform.

.br

.br
Returns 0 if OK.

.br

.br
This function is intended to stop a waveform started with the repeat mode.

.IP "\fBint wave_get_micros(void)\fP"
.IP "" 4
This function returns the length in microseconds of the current
waveform.

.IP "\fBint wave_get_high_micros(void)\fP"
.IP "" 4
This function returns the length in microseconds of the longest waveform
created since the pigpio daemon was started.

.IP "\fBint wave_get_max_micros(void)\fP"
.IP "" 4
This function returns the maximum possible size of a waveform in
.br
microseconds.

.IP "\fBint wave_get_pulses(void)\fP"
.IP "" 4
This function returns the length in pulses of the current waveform.

.IP "\fBint wave_get_high_pulses(void)\fP"
.IP "" 4
This function returns the length in pulses of the longest waveform
created since the pigpio daemon was started.

.IP "\fBint wave_get_max_pulses(void)\fP"
.IP "" 4
This function returns the maximum possible size of a waveform in pulses.

.IP "\fBint wave_get_cbs(void)\fP"
.IP "" 4
This function returns the length in DMA control blocks of the current
waveform.

.IP "\fBint wave_get_high_cbs(void)\fP"
.IP "" 4
This function returns the length in DMA control blocks of the longest
waveform created since the pigpio daemon was started.

.IP "\fBint wave_get_max_cbs(void)\fP"
.IP "" 4
This function returns the maximum possible size of a waveform in DMA
control blocks.

.IP "\fBint gpio_trigger(unsigned user_gpio, unsigned pulseLen, unsigned level)\fP"
.IP "" 4
This function sends a trigger pulse to a gpio.  The gpio is set to
level for pulseLen microseconds and then reset to not level.

.br

.br

.EX
user_gpio: 0-31.
.br
 pulseLen: 1-100.
.br
    level: 0,1.
.br

.EE

.br

.br
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_LEVEL,
PI_BAD_PULSELEN, or PI_NOT_PERMITTED.

.IP "\fBint store_script(char *script)\fP"
.IP "" 4
This function stores a script for later execution.

.br

.br

.EX
script: the text of the script.
.br

.EE

.br

.br
The function returns a script id if the script is valid,
otherwise PI_BAD_SCRIPT.

.IP "\fBint run_script(unsigned script_id, unsigned numPar, uint32_t *param)\fP"
.IP "" 4
This function runs a stored script.

.br

.br

.EX
script_id: >=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 bbBaud, unsigned bbBits)\fP"
.IP "" 4
This function opens a gpio for bit bang reading of serial data.

.br

.br

.EX
user_gpio: 0-31.
.br
   bbBaud: 100-250000
.br
   bbBits: 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 \fBbbBits\fP specified in the \fBbb_serial_read_open\fP command.

.br

.br
For \fBbbBits\fP 1-8 there will be one byte per character.
For \fBbbBits\fP 9-16 there will be two bytes per character.
For \fBbbBits\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 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: 0x08-0x77.
.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.

.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_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_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

.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

.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

.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

.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

.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

.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

.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

.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

.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

.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

.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.

.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.

.IP "\fBint spi_open(unsigned spi_channel, unsigned spi_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 B+ 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 B+ auxiliary device).
.br
   spi_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

.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 B+.

.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 ser_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
 ser_baud: the baud rate to use.
.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
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 count)\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
count: 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 count, 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
  argx: 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 fim
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 "\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 "\fBbbBaud\fP" 0
The baud rate used for the transmission and reception of bit banged
serial data.

.br

.br

.EX
PI_WAVE_MIN_BAUD 100
.br
PI_WAVE_MAX_BAUD 250000
.br

.EE

.br

.br

.IP "\fBbbBits\fP: 1-32" 0

.br

.br
The number of data bits to be used when adding serial data to a
waveform.

.br

.br

.EX
#define PI_MIN_WAVE_DATABITS 1
.br
#define PI_MAX_WAVE_DATABITS 32
.br

.EE

.br

.br

.IP "\fBbbStop\fP: 2-8" 0

.br

.br
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 "\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<<n).

.br

.br
e.g. to select bits 5, 9, 23 you could use (1<<5) | (1<<9) | (1<<23).

.br

.br

.IP "\fB*buf\fP" 0
A buffer to hold data being sent or being received.

.br

.br

.IP "\fBbufSize\fP" 0
The size in bytes of a buffer.

.br

.br

.br

.br

.IP "\fBbVal\fP: 0-255 (Hex 0x0-0xFF, Octal 0-0377)" 0
An 8-bit byte value.

.br

.br

.IP "\fBcallback_id\fP" 0
A >=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: 4689-250M" 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 "\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

.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: 0x08-0x77" 0
The address of a device on the I2C bus (0x08 - 0x77)

.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

.br

.br

.br

.br

.IP "\fBint\fP" 0
A whole number, negative or positive.

.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*param\fP" 0
An array of script parameters.

.br

.br

.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: 0-1000" 0
The hardware PWM dutycycle.

.br

.br

.EX
#define PI_HW_PWM_RANGE 1000
.br

.EE

.br

.br

.IP "\fBPWMfreq\fP: 5-250K" 0
The hardware PWM frequency.

.br

.br

.EX
#define PI_HW_PWM_MIN_FREQ 5
.br
#define PI_HW_PWM_MAX_FREQ 250000
.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*rxBuf\fP" 0
A pointer to a buffer to receive data.

.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

.br

.br

.IP "\fBseconds\fP" 0
The number of seconds.

.br

.br

.IP "\fBser_baud\fP" 0
The baud rate to use on the serial link.

.br

.br
It must be one of 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400,
4800, 9600, 19200, 38400, 57600, 115200, 230400.

.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_baud\fP" 0
The speed in bits per second to use for the SPI device.

.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 "\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

.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)
.SH AUTHOR

joan@abyz.co.uk