| pigpiod_if2(3) | pigpio archive | pigpiod_if2(3) |
pigpiod_if2 - A C library to interface to the pigpio daemon.
#include <pigpiod_if2.h>
gcc -Wall -pthread -o prog prog.c -lpigpiod_if2 -lrt
./prog
pigpiod_if2 is a C library for the Raspberry which allows control of the GPIO via the socket interface to the pigpio daemon.
o hardware timed PWM on any of GPIO 0-31
o hardware timed servo pulses on any of GPIO 0-31
o callbacks when any of GPIO 0-31 change state
o callbacks at timed intervals
o reading/writing all of the GPIO in a bank as one operation
o individually setting GPIO modes, reading and writing
o notifications when any of GPIO 0-31 change state
o the construction of output waveforms with microsecond timing
o rudimentary permission control over GPIO
o a simple interface to start and stop new threads
o I2C, SPI, and serial link wrappers
o creating and running scripts on the pigpio daemon
ALL GPIO are identified by their Broadcom number.
The PWM and servo pulses are timed using the DMA and PWM/PCM peripherals.
Include <pigpiod_if2.h> in your source files.
Assuming your source is in prog.c use the following command to build
gcc -Wall -pthread -o prog prog.c -lpigpiod_if2 -lrt
to run make sure the pigpio daemon is running
sudo pigpiod
./prog # sudo is not required to run programs linked to pigpiod_if2
For examples see x_pigpiod_if2.c within the pigpio archive file.
All the functions which return an int return < 0 on error
pigpio_start Connects to a pigpio daemon
pigpio_stop Disconnects from a pigpio daemon
set_mode Set a GPIO mode
get_mode Get a GPIO mode
set_pull_up_down Set/clear GPIO pull up/down resistor
gpio_read Read a GPIO
gpio_write Write a GPIO
set_PWM_dutycycle Start/stop PWM pulses on a GPIO
set_PWM_frequency Configure PWM frequency for a GPIO
set_PWM_range Configure PWM range for a GPIO
get_PWM_dutycycle Get the PWM dutycycle in use on a GPIO
get_PWM_frequency Get configured PWM frequency for a GPIO
get_PWM_range Get configured PWM range for a GPIO
get_PWM_real_range Get underlying PWM range for a GPIO
set_servo_pulsewidth Start/stop servo pulses on a GPIO
get_servo_pulsewidth Get the servo pulsewidth in use on a GPIO
gpio_trigger Send a trigger pulse to a GPIO.
set_watchdog Set a watchdog on a GPIO.
read_bank_1 Read all GPIO in bank 1
read_bank_2 Read all GPIO in bank 2
clear_bank_1 Clear selected GPIO in bank 1
clear_bank_2 Clear selected GPIO in bank 2
set_bank_1 Set selected GPIO in bank 1
set_bank_2 Set selected GPIO in bank 2
callback Create GPIO level change callback
callback_ex Create GPIO level change callback, extended
callback_cancel Cancel a callback
wait_for_edge Wait for GPIO level change
start_thread Start a new thread
stop_thread Stop a previously started thread
notify_open Request a notification handle
notify_begin Start notifications for selected GPIO
notify_pause Pause notifications
notify_close Close a notification
hardware_clock Start hardware clock on supported GPIO
hardware_PWM Start hardware PWM on supported GPIO
set_glitch_filter Set a glitch filter on a GPIO
set_noise_filter Set a noise filter on a GPIO
set_pad_strength Sets a pads drive strength
get_pad_strength Gets a pads drive strength
shell_ Executes a shell command
custom_1 User custom function 1
custom_2 User custom function 2
event_callback Sets a callback for an event
event_callback_ex Sets a callback for an event, extended
event_callback_cancel Cancel an event callback
event_trigger Triggers an event
wait_for_event Wait for an event
store_script Store a script
run_script Run a stored script
update_script Set a scripts parameters
script_status Get script status and parameters
stop_script Stop a running script
delete_script Delete a stored script
i2c_open Opens an I2C device
i2c_close Closes an I2C device
i2c_write_quick smbus write quick
i2c_read_byte smbus read byte
i2c_write_byte smbus write byte
i2c_read_byte_data smbus read byte data
i2c_write_byte_data smbus write byte data
i2c_read_word_data smbus read word data
i2c_write_word_data smbus write word data
i2c_read_block_data smbus read block data
i2c_write_block_data smbus write block data
i2c_read_i2c_block_data smbus read I2C block data
i2c_write_i2c_block_data smbus write I2C block data
i2c_read_device Reads the raw I2C device
i2c_write_device Writes the raw I2C device
i2c_process_call smbus process call
i2c_block_process_call smbus block process call
i2c_zip Performs multiple I2C transactions
bb_i2c_open Opens GPIO for bit banging I2C
bb_i2c_close Closes GPIO for bit banging I2C
bb_i2c_zip Performs bit banged I2C transactions
bsc_xfer I2C/SPI as slave transfer
bsc_i2c I2C as slave transfer
serial_open Opens a serial device
serial_close Closes a serial device
serial_read_byte Reads a byte from a serial device
serial_write_byte Writes a byte to a serial device
serial_read Reads bytes from a serial device
serial_write Writes bytes to a serial device
serial_data_available Returns number of bytes ready to be read
bb_serial_read_open Opens a GPIO for bit bang serial reads
bb_serial_read_close Closes a GPIO for bit bang serial reads
bb_serial_invert Invert serial logic (1 invert, 0 normal)
bb_serial_read Reads bit bang serial data from a GPIO
spi_open Opens a SPI device
spi_close Closes a SPI device
spi_read Reads bytes from a SPI device
spi_write Writes bytes to a SPI device
spi_xfer Transfers bytes with a SPI device
bb_spi_open Opens GPIO for bit banging SPI
bb_spi_close Closes GPIO for bit banging SPI
bb_spi_xfer Transfers bytes with bit banging SPI
file_open Opens a file
file_close Closes a file
file_read Reads bytes from a file
file_write Writes bytes to a file
file_seek Seeks to a position within a file
file_list List files which match a pattern
wave_clear Deletes all waveforms
wave_add_new Starts a new waveform
wave_add_generic Adds a series of pulses to the waveform
wave_add_serial Adds serial data to the waveform
wave_create Creates a waveform from added data
wave_create_and_pad Creates a waveform of fixed size from added data
wave_delete Deletes one or more waveforms
wave_send_once Transmits a waveform once
wave_send_repeat Transmits a waveform repeatedly
wave_send_using_mode Transmits a waveform in the chosen mode
wave_chain Transmits a chain of waveforms
wave_tx_at Returns the current transmitting waveform
wave_tx_busy Checks to see if the waveform has ended
wave_tx_stop Aborts the current waveform
wave_get_cbs Length in cbs of the current waveform
wave_get_high_cbs Length of longest waveform so far
wave_get_max_cbs Absolute maximum allowed cbs
wave_get_micros Length in micros of the current waveform
wave_get_high_micros Length of longest waveform so far
wave_get_max_micros Absolute maximum allowed micros
wave_get_pulses Length in pulses of the current waveform
wave_get_high_pulses Length of longest waveform so far
wave_get_max_pulses Absolute maximum allowed pulses
get_current_tick Get current tick (microseconds)
get_hardware_revision Get hardware revision
get_pigpio_version Get the pigpio version
pigpiod_if_version Get the pigpiod_if2 version
pigpio_error Get a text description of an error code.
time_sleep Sleeps for a float number of seconds
time_time Float number of seconds since the epoch
seconds: the number of seconds to delay.
errnum: the error code.
thread_func: the main function for the new thread.
userdata: a pointer to an arbitrary argument.
Returns a pointer to pthread_t if OK, otherwise NULL.
The function is passed the single argument userdata.
The thread can be cancelled by passing the pointer to pthread_t to stop_thread.
pth: the thread to be stopped.
No value is returned.
The thread to be stopped should have been started with start_thread.
addrStr: specifies 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.
portStr: specifies 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.
Returns an integer value greater than or equal to zero if OK.
This value is passed to the GPIO routines to specify the Pi to be operated on.
pi: >=0 (as returned by pigpio_start).
pi: >=0 (as returned by pigpio_start).
gpio: 0-53.
mode: PI_INPUT, PI_OUTPUT, PI_ALT0, PI_ALT1,
PI_ALT2, PI_ALT3, PI_ALT4, PI_ALT5.
Returns 0 if OK, otherwise PI_BAD_GPIO, PI_BAD_MODE, or PI_NOT_PERMITTED.
pi: >=0 (as returned by pigpio_start).
gpio: 0-53.
Returns the GPIO mode if OK, otherwise PI_BAD_GPIO.
pi: >=0 (as returned by pigpio_start).
gpio: 0-53.
pud: PI_PUD_UP, PI_PUD_DOWN, PI_PUD_OFF.
Returns 0 if OK, otherwise PI_BAD_GPIO, PI_BAD_PUD, or PI_NOT_PERMITTED.
pi: >=0 (as returned by pigpio_start).
gpio:0-53.
Returns the GPIO level if OK, otherwise PI_BAD_GPIO.
pi: >=0 (as returned by pigpio_start).
gpio: 0-53.
level: 0, 1.
Returns 0 if OK, otherwise PI_BAD_GPIO, PI_BAD_LEVEL, or PI_NOT_PERMITTED.
Notes
If PWM or servo pulses are active on the GPIO they are switched off.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
dutycycle: 0-range (range defaults to 255).
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_DUTYCYCLE, or PI_NOT_PERMITTED. Notes
The set_PWM_range function may be used to change the default range of 255.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
Returns 0 if OK, otherwise PI_BAD_USER_GPIO or PI_NOT_PWM_GPIO.
For normal PWM the dutycycle will be out of the defined range for the GPIO (see get_PWM_range).
If a hardware clock is active on the GPIO the reported dutycycle will be 500000 (500k) out of 1000000 (1M).
If hardware PWM is active on the GPIO the reported dutycycle will be out of a 1000000 (1M).
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
range: 25-40000.
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_DUTYRANGE, or PI_NOT_PERMITTED.
Notes
If PWM is currently active on the GPIO its dutycycle will be scaled to reflect the new range.
The real range, the number of steps between fully off and fully on for each of the 18 available GPIO frequencies is
25(#1), 50(#2), 100(#3), 125(#4), 200(#5), 250(#6),
400(#7), 500(#8), 625(#9), 800(#10), 1000(#11), 1250(#12),
2000(#13), 2500(#14), 4000(#15), 5000(#16), 10000(#17), 20000(#18)
The real value set by set_PWM_range is (dutycycle * real range) / range.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
Returns the dutycycle range used for the GPIO if OK, otherwise PI_BAD_USER_GPIO.
If a hardware clock or hardware PWM is active on the GPIO the reported range will be 1000000 (1M).
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
Returns the real range used for the GPIO if OK, otherwise PI_BAD_USER_GPIO.
If a hardware clock is active on the GPIO the reported real range will be 1000000 (1M).
If hardware PWM is active on the GPIO the reported real range will be approximately 250M divided by the set PWM frequency.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
frequency: >=0 (Hz).
Returns the numerically closest frequency if OK, otherwise PI_BAD_USER_GPIO or PI_NOT_PERMITTED.
If PWM is currently active on the GPIO it will be switched off and then back on at the new frequency.
Each GPIO can be independently set to one of 18 different PWM frequencies.
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 pigpio daemon is started.
The frequencies for each sample rate are:
Hertz
1: 40000 20000 10000 8000 5000 4000 2500 2000 1600
1250 1000 800 500 400 250 200 100 50
2: 20000 10000 5000 4000 2500 2000 1250 1000 800
625 500 400 250 200 125 100 50 25
4: 10000 5000 2500 2000 1250 1000 625 500 400
313 250 200 125 100 63 50 25 13
sample
rate
(us) 5: 8000 4000 2000 1600 1000 800 500 400 320
250 200 160 100 80 50 40 20 10
8: 5000 2500 1250 1000 625 500 313 250 200
156 125 100 63 50 31 25 13 6
10: 4000 2000 1000 800 500 400 250 200 160
125 100 80 50 40 25 20 10 5
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
For normal PWM the frequency will be that defined for the GPIO by set_PWM_frequency.
If a hardware clock is active on the GPIO the reported frequency will be that set by hardware_clock.
If hardware PWM is active on the GPIO the reported frequency will be that set by hardware_PWM.
Returns the frequency (in hertz) used for the GPIO if OK, otherwise PI_BAD_USER_GPIO.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
pulsewidth: 0 (off), 500 (anti-clockwise) - 2500 (clockwise).
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_PULSEWIDTH or PI_NOT_PERMITTED.
The selected pulsewidth will continue to be transmitted until changed by a subsequent call to set_servo_pulsewidth.
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.
You can DAMAGE a servo if you command it to move beyond its limits.
OTHER UPDATE RATES:
This function updates servos at 50Hz. If you wish to use a different update frequency you will have to use the PWM functions.
Update Rate (Hz) 50 100 200 400 500
1E6/Hz 20000 10000 5000 2500 2000
Firstly set the desired PWM frequency using set_PWM_frequency.
Then set the PWM range using set_PWM_range to 1E6/Hz. Doing this allows you to use units of microseconds when setting the servo pulsewidth.
E.g. If you want to update a servo connected to GPIO 25 at 400Hz
set_PWM_frequency(25, 400);
set_PWM_range(25, 2500);
Thereafter use the set_PWM_dutycycle function to move the servo, e.g. set_PWM_dutycycle(25, 1500) will set a 1500 us pulse.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
Returns 0 if OK, otherwise PI_BAD_USER_GPIO or PI_NOT_SERVO_GPIO.
pi: >=0 (as returned by pigpio_start).
Returns a handle greater than or equal to zero if OK, otherwise PI_NO_HANDLE.
A notification is a method for being notified of GPIO state changes via a pipe.
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 callback should be used instead.
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.
pi: >=0 (as returned by pigpio_start).
handle: 0-31 (as returned by notify_open)
bits: a mask indicating the GPIO to be notified.
Returns 0 if OK, otherwise PI_BAD_HANDLE.
The notification sends state changes for each GPIO whose corresponding bit in bits is set.
Each notification occupies 12 bytes in the fifo as follows:
typedef struct
{
uint16_t seqno;
uint16_t flags;
uint32_t tick;
uint32_t level;
} gpioReport_t;
seqno: starts at 0 each time the handle is opened and then increments by one for each report.
flags: three flags are defined, PI_NTFY_FLAGS_WDOG, PI_NTFY_FLAGS_ALIVE, and PI_NTFY_FLAGS_EVENT.
If bit 5 is set (PI_NTFY_FLAGS_WDOG) then bits 0-4 of the flags indicate a GPIO which has had a watchdog timeout.
If bit 6 is set (PI_NTFY_FLAGS_ALIVE) this indicates a keep alive signal on the pipe/socket and is sent once a minute in the absence of other notification activity.
If bit 7 is set (PI_NTFY_FLAGS_EVENT) then bits 0-4 of the flags indicate an event which has been triggered.
tick: the number of microseconds since system boot. It wraps around after 1h12m.
level: indicates the level of each GPIO. If bit 1<<x is set then GPIO x is high.
pi: >=0 (as returned by pigpio_start).
handle: 0-31 (as returned by notify_open)
Returns 0 if OK, otherwise PI_BAD_HANDLE.
Notifications for the handle are suspended until notify_begin is called again.
pi: >=0 (as returned by pigpio_start).
handle: 0-31 (as returned by notify_open)
Returns 0 if OK, otherwise PI_BAD_HANDLE.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
timeout: 0-60000.
Returns 0 if OK, otherwise PI_BAD_USER_GPIO or PI_BAD_WDOG_TIMEOUT.
The watchdog is nominally in milliseconds.
Only one watchdog may be registered per GPIO.
The watchdog may be cancelled by setting timeout to 0.
Once a watchdog has been started callbacks for the GPIO will be triggered every timeout interval after the last GPIO activity.
The callback will receive the special level PI_TIMEOUT.
Level changes on the GPIO are not reported unless the level has been stable for at least steady microseconds. The level is then reported. Level changes of less than steady microseconds are ignored.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31
steady: 0-300000
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, or PI_BAD_FILTER.
This filter affects the GPIO samples returned to callbacks set up with callback, callback_ex and wait_for_edge.
It does not affect levels read by gpio_read, read_bank_1, or read_bank_2.
Each (stable) edge will be timestamped steady microseconds after it was first detected.
Level changes on the GPIO are ignored until a level which has been stable for steady microseconds is detected. Level changes on the GPIO are then reported for active microseconds after which the process repeats.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31
steady: 0-300000
active: 0-1000000
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, or PI_BAD_FILTER.
This filter affects the GPIO samples returned to callbacks set up with callback, callback_ex and wait_for_edge.
It does not affect levels read by gpio_read, read_bank_1, or read_bank_2.
Level changes before and after the active period may be reported. Your software must be designed to cope with such reports.
pi: >=0 (as returned by pigpio_start).
The returned 32 bit integer has a bit set if the corresponding GPIO is logic 1. GPIO n has bit value (1<<n).
pi: >=0 (as returned by pigpio_start).
The returned 32 bit integer has a bit set if the corresponding GPIO is logic 1. GPIO n has bit value (1<<(n-32)).
pi: >=0 (as returned by pigpio_start).
bits: a bit mask with 1 set if the corresponding GPIO is
to be cleared.
Returns 0 if OK, otherwise PI_SOME_PERMITTED.
A status of PI_SOME_PERMITTED indicates that the user is not allowed to write to one or more of the GPIO.
pi: >=0 (as returned by pigpio_start).
bits: a bit mask with 1 set if the corresponding GPIO is
to be cleared.
Returns 0 if OK, otherwise PI_SOME_PERMITTED.
A status of PI_SOME_PERMITTED indicates that the user is not allowed to write to one or more of the GPIO.
pi: >=0 (as returned by pigpio_start).
bits: a bit mask with 1 set if the corresponding GPIO is
to be set.
Returns 0 if OK, otherwise PI_SOME_PERMITTED.
A status of PI_SOME_PERMITTED indicates that the user is not allowed to write to one or more of the GPIO.
pi: >=0 (as returned by pigpio_start).
bits: a bit mask with 1 set if the corresponding GPIO is
to be set.
Returns 0 if OK, otherwise PI_SOME_PERMITTED.
A status of PI_SOME_PERMITTED indicates that the user is not allowed to write to one or more of the GPIO.
pi: >=0 (as returned by pigpio_start).
gpio: see description
frequency: 0 (off) or 4689-250M (13184-375M for the BCM2711)
Returns 0 if OK, otherwise PI_NOT_PERMITTED, PI_BAD_GPIO, PI_NOT_HCLK_GPIO, PI_BAD_HCLK_FREQ,or PI_BAD_HCLK_PASS.
The same clock is available on multiple GPIO. The latest frequency setting will be used by all GPIO which share a clock.
The GPIO must be one of the following.
4 clock 0 All models
5 clock 1 All models but A and B (reserved for system use)
6 clock 2 All models but A and B
20 clock 0 All models but A and B
21 clock 1 All models but A and Rev.2 B (reserved for system use)
32 clock 0 Compute module only
34 clock 0 Compute module only
42 clock 1 Compute module only (reserved for system use)
43 clock 2 Compute module only
44 clock 1 Compute module only (reserved for system use)
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.
NOTE: Any waveform started by wave_send_* or wave_chain will be cancelled.
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).
pi: >=0 (as returned by pigpio_start).
gpio: see descripton
PWMfreq: 0 (off) or 1-125M (1-187.5M for the BCM2711)
PWMduty: 0 (off) to 1000000 (1M)(fully on)
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.
The same PWM channel is available on multiple GPIO. The latest frequency and dutycycle setting will be used by all GPIO which share a PWM channel.
The GPIO must be one of the following.
12 PWM channel 0 All models but A and B
13 PWM channel 1 All models but A and B
18 PWM channel 0 All models
19 PWM channel 1 All models but A and B
40 PWM channel 0 Compute module only
41 PWM channel 1 Compute module only
45 PWM channel 1 Compute module only
52 PWM channel 0 Compute module only
53 PWM channel 1 Compute module only
The actual number of steps beween off and fully on is the integral part of 250M/PWMfreq (375M/PWMfreq for the BCM2711).
The actual frequency set is 250M/steps (375M/steps for the BCM2711).
There will only be a million steps for a PWMfreq of 250 (375 for the BCM2711). Lower frequencies will have more steps and higher frequencies will have fewer steps. PWMduty is automatically scaled to take this into account.
pi: >=0 (as returned by pigpio_start).
Tick is the number of microseconds since system boot.
As tick is an unsigned 32 bit quantity it wraps around after 2**32 microseconds, which is approximately 1 hour 12 minutes.
pi: >=0 (as returned by pigpio_start).
The hardware revision is the last few characters on the Revision line of /proc/cpuinfo.
If the hardware revision can not be found or is not a valid hexadecimal number the function returns 0.
The revision number can be used to determine the assignment of GPIO to pins (see gpio).
There are at least three types of board.
Type 1 boards have hardware revision numbers of 2 and 3.
Type 2 boards have hardware revision numbers of 4, 5, 6, and 15.
Type 3 boards have hardware revision numbers of 16 or greater.
pi: >=0 (as returned by pigpio_start).
pi: >=0 (as returned by pigpio_start).
Returns 0 if OK.
pi: >=0 (as returned by pigpio_start).
Returns 0 if OK.
pi: >=0 (as returned by pigpio_start).
numPulses: the number of pulses.
pulses: an array of pulses.
Returns the new total number of pulses in the current waveform if OK, otherwise PI_TOO_MANY_PULSES.
The pulses are interleaved in time order within the existing waveform (if any).
Merging allows the waveform to be built in parts, that is the settings for GPIO#1 can be added, and then GPIO#2 etc.
If the added waveform is intended to start after or within the existing waveform then the first pulse should consist solely of a delay.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
baud: 50-1000000
data_bits: number of data bits (1-32)
stop_bits: number of stop half bits (2-8)
offset: >=0
numBytes: >=1
str: an array of chars.
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.
NOTES:
The serial data is formatted as one start bit, data_bits data bits, and stop_bits/2 stop bits.
It is legal to add serial data streams with different baud rates to the same waveform.
numBytes is the number of bytes of data in str.
The bytes required for each character depend upon data_bits.
For data_bits 1-8 there will be one byte per character.
For data_bits 9-16 there will be two bytes per character.
For data_bits 17-32 there will be four bytes per character.
pi: >=0 (as returned by pigpio_start).
The data provided by the wave_add_* functions is consumed by this function.
As many waveforms may be created as there is space available. The wave id is passed to wave_send_* to specify the waveform to transmit.
Normal usage would be
Step 1. wave_clear to clear all waveforms and added data.
Step 2. wave_add_* calls to supply the waveform data.
Step 3. wave_create to create the waveform and get a unique id
Repeat steps 2 and 3 as needed.
Step 4. wave_send_* with the id of the waveform to transmit.
A waveform comprises one or more pulses. Each pulse consists of a gpioPulse_t structure.
typedef struct
{
uint32_t gpioOn;
uint32_t gpioOff;
uint32_t usDelay;
} gpioPulse_t;
The fields specify
1) the GPIO to be switched on at the start of the pulse.
2) the GPIO to be switched off at the start of the pulse.
3) the delay in microseconds before the next pulse.
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).
When a waveform is started each pulse is executed in order with the specified delay between the pulse and the next.
Returns the new waveform id if OK, otherwise PI_EMPTY_WAVEFORM, PI_NO_WAVEFORM_ID, PI_TOO_MANY_CBS, or PI_TOO_MANY_OOL.
pi: >=0 (as returned by pigpio_start).
percent: 0-100, size of waveform as percentage of maximum available.
The data provided by the wave_add_* functions are consumed by this function.
As many waveforms may be created as there is space available. The wave id is passed to wave_send_* to specify the waveform to transmit.
A usage would be the creation of two waves where one is filled while the other is being transmitted. Each wave is assigned 50% of the resources. This buffer structure allows the transmission of infinite wave sequences.
Normal usage:
Step 1. wave_clear to clear all waveforms and added data.
Step 2. wave_add_* calls to supply the waveform data.
Step 3. wave_create_and_pad to create a waveform of uniform size.
Step 4. wave_send_* with the id of the waveform to transmit.
Repeat steps 2-4 as needed.
Step 5. Any wave id can now be deleted and another wave of the
same size
can be created in its place.
Returns the new waveform id if OK, otherwise PI_EMPTY_WAVEFORM, PI_NO_WAVEFORM_ID, PI_TOO_MANY_CBS, or PI_TOO_MANY_OOL.
pi: >=0 (as returned by pigpio_start).
wave_id: >=0, as returned by wave_create.
Wave ids are allocated in order, 0, 1, 2, etc.
The wave is flagged for deletion. The resources used by the wave will only be reused when either of the following apply.
- all waves with higher numbered wave ids have been deleted or have been flagged for deletion.
- a new wave is created which uses exactly the same resources as the current wave (see the C source for gpioWaveCreate for details).
Returns 0 if OK, otherwise PI_BAD_WAVE_ID.
NOTE: Any hardware PWM started by hardware_PWM will be cancelled.
pi: >=0 (as returned by pigpio_start).
wave_id: >=0, as returned by wave_create.
Returns the number of DMA control blocks in the waveform if OK, otherwise PI_BAD_WAVE_ID, or PI_BAD_WAVE_MODE.
NOTE: Any hardware PWM started by hardware_PWM will be cancelled.
pi: >=0 (as returned by pigpio_start).
wave_id: >=0, as returned by wave_create.
Returns the number of DMA control blocks in the waveform if OK, otherwise PI_BAD_WAVE_ID, or PI_BAD_WAVE_MODE.
pi: >=0 (as returned by pigpio_start).
wave_id: >=0, as returned by wave_create.
mode: PI_WAVE_MODE_ONE_SHOT, PI_WAVE_MODE_REPEAT,
PI_WAVE_MODE_ONE_SHOT_SYNC, or PI_WAVE_MODE_REPEAT_SYNC.
PI_WAVE_MODE_ONE_SHOT: same as wave_send_once.
PI_WAVE_MODE_REPEAT same as wave_send_repeat.
PI_WAVE_MODE_ONE_SHOT_SYNC same as wave_send_once but tries to sync with the previous waveform.
PI_WAVE_MODE_REPEAT_SYNC same as wave_send_repeat but tries to sync with the previous waveform.
WARNING: bad things may happen if you delete the previous waveform before it has been synced to the new waveform.
NOTE: Any hardware PWM started by hardware_PWM will be cancelled.
Returns the number of DMA control blocks in the waveform if OK, otherwise PI_BAD_WAVE_ID, or PI_BAD_WAVE_MODE.
NOTE: Any hardware PWM started by hardware_PWM will be cancelled.
The waves to be transmitted are specified by the contents of buf which contains an ordered list of wave_ids and optional command codes and related data.
pi: >=0 (as returned by pigpio_start).
buf: pointer to the wave_ids and optional command codes
bufSize: the number of bytes in buf
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.
Each wave is transmitted in the order specified. A wave may occur multiple times per chain.
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.
Delays between waves may be added with the delay command.
The following command codes are supported:
Name Cmd & Data Meaning
Loop Start 255 0 Identify start of a wave block
Loop Repeat 255 1 x y loop x + y*256 times
Delay 255 2 x y delay x + y*256 microseconds
Loop Forever 255 3 loop forever
If present Loop Forever must be the last entry in the chain.
The code is currently dimensioned to support a chain with roughly 600 entries and 20 loop counters.
Example
#include <stdio.h>
#include <pigpiod_if2.h>
#define WAVES 5
#define GPIO 4
int main(int argc, char *argv[])
{
int i, pi, wid[WAVES];
pi = pigpio_start(0, 0);
if (pi<0) return -1;
set_mode(pi, GPIO, PI_OUTPUT);
for (i=0; i<WAVES; i++)
{
wave_add_generic(pi, 2, (gpioPulse_t[])
{{1<<GPIO, 0, 20},
{0, 1<<GPIO, (i+1)*200}});
wid[i] = wave_create(pi);
}
wave_chain(pi, (char []) {
wid[4], wid[3], wid[2], // transmit waves 4+3+2
255, 0, // loop start
wid[0], wid[0], wid[0], // transmit waves 0+0+0
255, 0, // loop start
wid[0], wid[1], // transmit waves 0+1
255, 2, 0x88, 0x13, // delay 5000us
255, 1, 30, 0, // loop end (repeat 30 times)
255, 0, // loop start
wid[2], wid[3], wid[0], // transmit waves 2+3+0
wid[3], wid[1], wid[2], // transmit waves 3+1+2
255, 1, 10, 0, // loop end (repeat 10 times)
255, 1, 5, 0, // loop end (repeat 5 times)
wid[4], wid[4], wid[4], // transmit waves 4+4+4
255, 2, 0x20, 0x4E, // delay 20000us
wid[0], wid[0], wid[0], // transmit waves 0+0+0
}, 46);
while (wave_tx_busy(pi)) time_sleep(0.1);
for (i=0; i<WAVES; i++) wave_delete(pi, wid[i]);
pigpio_stop(pi);
}
pi: >=0 (as returned by pigpio_start).
Returns the waveform id or one of the following special values:
PI_WAVE_NOT_FOUND (9998) - transmitted wave not found.
PI_NO_TX_WAVE (9999) - no wave being transmitted.
pi: >=0 (as returned by pigpio_start).
Returns 1 if a waveform is currently being transmitted, otherwise 0.
pi: >=0 (as returned by pigpio_start).
Returns 0 if OK.
This function is intended to stop a waveform started with the repeat mode.
pi: >=0 (as returned by pigpio_start).
pi: >=0 (as returned by pigpio_start).
pi: >=0 (as returned by pigpio_start).
pi: >=0 (as returned by pigpio_start).
pi: >=0 (as returned by pigpio_start).
pi: >=0 (as returned by pigpio_start).
pi: >=0 (as returned by pigpio_start).
pi: >=0 (as returned by pigpio_start).
pi: >=0 (as returned by pigpio_start).
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
pulseLen: 1-100.
level: 0,1.
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_LEVEL, PI_BAD_PULSELEN, or PI_NOT_PERMITTED.
See http://abyz.me.uk/rpi/pigpio/pigs.html#Scripts for details.
pi: >=0 (as returned by pigpio_start).
script: the text of the script.
The function returns a script id if the script is valid, otherwise PI_BAD_SCRIPT.
pi: >=0 (as returned by pigpio_start).
script_id: >=0, as returned by store_script.
numPar: 0-10, the number of parameters.
param: an array of parameters.
The function returns 0 if OK, otherwise PI_BAD_SCRIPT_ID, or PI_TOO_MANY_PARAM
param is an array of up to 10 parameters which may be referenced in the script as p0 to p9.
pi: >=0 (as returned by pigpio_start).
script_id: >=0, as returned by store_script.
numPar: 0-10, the number of parameters.
param: an array of parameters.
The function returns 0 if OK, otherwise PI_BAD_SCRIPT_ID, or PI_TOO_MANY_PARAM.
param is an array of up to 10 parameters which may be referenced in the script as p0 to p9.
pi: >=0 (as returned by pigpio_start).
script_id: >=0, as returned by store_script.
param: an array to hold the returned 10 parameters.
The function returns greater than or equal to 0 if OK, otherwise PI_BAD_SCRIPT_ID.
The run status may be
PI_SCRIPT_INITING
PI_SCRIPT_HALTED
PI_SCRIPT_RUNNING
PI_SCRIPT_WAITING
PI_SCRIPT_FAILED
The current value of script parameters 0 to 9 are returned in param.
pi: >=0 (as returned by pigpio_start).
script_id: >=0, as returned by store_script.
The function returns 0 if OK, otherwise PI_BAD_SCRIPT_ID.
pi: >=0 (as returned by pigpio_start).
script_id: >=0, as returned by store_script.
The function returns 0 if OK, otherwise PI_BAD_SCRIPT_ID.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
baud: 50-250000
data_bits: 1-32
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_WAVE_BAUD, or PI_GPIO_IN_USE.
The serial data is returned in a cyclic buffer and is read using bb_serial_read.
It is the caller's responsibility to read data from the cyclic buffer in a timely fashion.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31, previously opened with bb_serial_read_open.
buf: an array to receive the read bytes.
bufSize: >=0
Returns the number of bytes copied if OK, otherwise PI_BAD_USER_GPIO or PI_NOT_SERIAL_GPIO.
The bytes returned for each character depend upon the number of data bits data_bits specified in the bb_serial_read_open command.
For data_bits 1-8 there will be one byte per character.
For data_bits 9-16 there will be two bytes per character.
For data_bits 17-32 there will be four bytes per character.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31, previously opened with bb_serial_read_open.
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, or PI_NOT_SERIAL_GPIO.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31, previously opened with bb_serial_read_open.
invert: 0-1, 1 invert, 0 normal.
Returns 0 if OK, otherwise PI_NOT_SERIAL_GPIO or PI_BAD_SER_INVERT.
pi: >=0 (as returned by pigpio_start).
i2c_bus: >=0.
i2c_addr: 0-0x7F.
i2c_flags: 0.
No flags are currently defined. This parameter should be set to zero.
Physically buses 0 and 1 are available on the Pi. Higher numbered buses will be available if a kernel supported bus multiplexor is being used.
The GPIO used are given in the following table.
SDA SCL
I2C 0 0 1
I2C 1 2 3
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.
For the SMBus commands the low level transactions are shown at the end of the function description. The following abbreviations are used.
S (1 bit) : Start bit
P (1 bit) : Stop bit
Rd/Wr (1 bit) : Read/Write bit. Rd equals 1, Wr equals 0.
A, NA (1 bit) : Accept and not accept bit.
Addr (7 bits): I2C 7 bit address.
i2c_reg (8 bits): A byte which often selects a register.
Data (8 bits): A data byte.
Count (8 bits): A byte defining the length of a block operation.
[..]: Data sent by the device.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
Returns 0 if OK, otherwise PI_BAD_HANDLE.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
bit: 0-1, the value to write.
Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED.
Quick command. SMBus 2.0 5.5.1
S Addr bit [A] P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
bVal: 0-0xFF, the value to write.
Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED.
Send byte. SMBus 2.0 5.5.2
S Addr Wr [A] bVal [A] P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
Returns the byte read (>=0) if OK, otherwise PI_BAD_HANDLE, or PI_I2C_READ_FAILED.
Receive byte. SMBus 2.0 5.5.3
S Addr Rd [A] [Data] NA P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
i2c_reg: 0-255, the register to write.
bVal: 0-0xFF, the value to write.
Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED.
Write byte. SMBus 2.0 5.5.4
S Addr Wr [A] i2c_reg [A] bVal [A] P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
i2c_reg: 0-255, the register to write.
wVal: 0-0xFFFF, the value to write.
Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED.
Write word. SMBus 2.0 5.5.4
S Addr Wr [A] i2c_reg [A] wval_Low [A] wVal_High [A] P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
i2c_reg: 0-255, the register to read.
Returns the byte read (>=0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED.
Read byte. SMBus 2.0 5.5.5
S Addr Wr [A] i2c_reg [A] S Addr Rd [A] [Data] NA P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
i2c_reg: 0-255, the register to read.
Returns the word read (>=0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED.
Read word. SMBus 2.0 5.5.5
S Addr Wr [A] i2c_reg [A]
S Addr Rd [A] [DataLow] A [DataHigh] NA P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
i2c_reg: 0-255, the register to write/read.
wVal: 0-0xFFFF, the value to write.
Returns the word read (>=0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED.
Process call. SMBus 2.0 5.5.6
S Addr Wr [A] i2c_reg [A] wVal_Low [A] wVal_High [A]
S Addr Rd [A] [DataLow] A [DataHigh] NA P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
i2c_reg: 0-255, the register to write.
buf: an array with the data to send.
count: 1-32, the number of bytes to write.
Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED.
Block write. SMBus 2.0 5.5.7
S Addr Wr [A] i2c_reg [A] count [A] buf0 [A] buf1 [A] ...
[A] bufn [A] P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
i2c_reg: 0-255, the register to read.
buf: an array to receive the read data.
The amount of returned data is set by the device.
Returns the number of bytes read (>=0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED.
Block read. SMBus 2.0 5.5.7
S Addr Wr [A] i2c_reg [A]
S Addr Rd [A] [Count] A [buf0] A [buf1] A ... A [bufn] NA P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
i2c_reg: 0-255, the register to write/read.
buf: an array with the data to send and to receive the read data.
count: 1-32, the number of bytes to write.
Returns the number of bytes read (>=0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED.
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.
Block write-block read. SMBus 2.0 5.5.8
S Addr Wr [A] i2c_reg [A] count [A] buf0 [A] ...
S Addr Rd [A] [Count] A [Data] ... A P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
i2c_reg: 0-255, the register to read.
buf: an array to receive the read data.
count: 1-32, the number of bytes to read.
Returns the number of bytes read (>0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED.
S Addr Wr [A] i2c_reg [A]
S Addr Rd [A] [buf0] A [buf1] A ... A [bufn] NA P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
i2c_reg: 0-255, the register to write.
buf: the data to write.
count: 1-32, the number of bytes to write.
Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED.
S Addr Wr [A] i2c_reg [A] buf0 [A] buf1 [A] ... [A] bufn [A] P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
buf: an array to receive the read data bytes.
count: >0, the number of bytes to read.
Returns count (>0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_READ_FAILED.
S Addr Rd [A] [buf0] A [buf1] A ... A [bufn] NA P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2c_open.
buf: an array containing the data bytes to write.
count: >0, the number of bytes to write.
Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_I2C_WRITE_FAILED.
S Addr Wr [A] buf0 [A] buf1 [A] ... [A] bufn [A] P
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to i2cOpen
inBuf: pointer to the concatenated I2C commands, see below
inLen: size of command buffer
outBuf: pointer to buffer to hold returned data
outLen: size of output buffer
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.
The following command codes are supported:
Name Cmd & Data Meaning
End 0 No more commands
Escape 1 Next P is two bytes
On 2 Switch combined flag on
Off 3 Switch combined flag off
Address 4 P Set I2C address to P
Flags 5 lsb msb Set I2C flags to lsb + (msb << 8)
Read 6 P Read P bytes of data
Write 7 P ... Write P bytes of data
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).
The address defaults to that associated with the handle. The flags default to 0. The address and flags maintain their previous value until updated.
The returned I2C data is stored in consecutive locations of outBuf.
Example
Set address 0x53, write 0x32, read 6 bytes
Set address 0x1E, write 0x03, read 6 bytes
Set address 0x68, write 0x1B, read 8 bytes
End
0x04 0x53 0x07 0x01 0x32 0x06 0x06
0x04 0x1E 0x07 0x01 0x03 0x06 0x06
0x04 0x68 0x07 0x01 0x1B 0x06 0x08
0x00
Bit banging I2C allows for certain operations which are not possible with the standard I2C driver.
o baud rates as low as 50
o repeated starts
o clock stretching
o I2C on any pair of spare GPIO
pi: >=0 (as returned by pigpio_start).
SDA: 0-31
SCL: 0-31
baud: 50-500000
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_I2C_BAUD, or PI_GPIO_IN_USE.
NOTE:
The GPIO 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.
pi: >=0 (as returned by pigpio_start).
SDA: 0-31, the SDA GPIO used in a prior call to bb_i2c_open
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, or PI_NOT_I2C_GPIO.
pi: >=0 (as returned by pigpio_start).
SDA: 0-31 (as used in a prior call to bb_i2c_open)
inBuf: pointer to the concatenated I2C commands, see below
inLen: size of command buffer
outBuf: pointer to buffer to hold returned data
outLen: size of output buffer
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.
The following command codes are supported:
Name Cmd & Data Meaning
End 0 No more commands
Escape 1 Next P is two bytes
Start 2 Start condition
Stop 3 Stop condition
Address 4 P Set I2C address to P
Flags 5 lsb msb Set I2C flags to lsb + (msb << 8)
Read 6 P Read P bytes of data
Write 7 P ... Write P bytes of data
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).
The address and flags default to 0. The address and flags maintain their previous value until updated.
No flags are currently defined.
The returned I2C data is stored in consecutive locations of outBuf.
Example
Set address 0x53
start, write 0x32, (re)start, read 6 bytes, stop
Set address 0x1E
start, write 0x03, (re)start, read 6 bytes, stop
Set address 0x68
start, write 0x1B, (re)start, read 8 bytes, stop
End
0x04 0x53
0x02 0x07 0x01 0x32 0x02 0x06 0x06 0x03
0x04 0x1E
0x02 0x07 0x01 0x03 0x02 0x06 0x06 0x03
0x04 0x68
0x02 0x07 0x01 0x1B 0x02 0x06 0x08 0x03
0x00
pi: >=0 (as returned by pigpio_start).
CS: 0-31
MISO: 0-31
MOSI: 0-31
SCLK: 0-31
baud: 50-250000
spi_flags: see below
spi_flags consists of the least significant 22 bits.
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 0 0 0 0 R T 0 0 0 0 0 0 0 0 0 0 0 p m m
mm defines the SPI mode, defaults to 0
Mode CPOL CPHA
0 0 0
1 0 1
2 1 0
3 1 1
p is 0 if CS is active low (default) and 1 for active high.
T is 1 if the least significant bit is transmitted on MOSI first, the default (0) shifts the most significant bit out first.
R is 1 if the least significant bit is received on MISO first, the default (0) receives the most significant bit first.
The other bits in flags should be set to zero.
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_SPI_BAUD, or PI_GPIO_IN_USE.
If more than one device is connected to the SPI bus (defined by SCLK, MOSI, and MISO) each must have its own CS.
Example
bb_spi_open(pi,10, MISO, MOSI, SCLK, 10000, 0); // device 1
bb_spi_open(pi,11, MISO, MOSI, SCLK, 20000, 3); // device 2
pi: >=0 (as returned by pigpio_start).
CS: 0-31, the CS GPIO used in a prior call to bb_spi_open
Returns 0 if OK, otherwise PI_BAD_USER_GPIO, or PI_NOT_SPI_GPIO.
pi: >=0 (as returned by pigpio_start).
CS: 0-31 (as used in a prior call to bb_spi_open)
txBuf: pointer to buffer to hold data to be sent
rxBuf: pointer to buffer to hold returned data
count: size of data transfer
Returns >= 0 if OK (the number of bytes read), otherwise PI_BAD_USER_GPIO, PI_NOT_SPI_GPIO or PI_BAD_POINTER.
Example
// gcc -Wall -pthread -o bb_spi_x_test bb_spi_x_test.c -lpigpiod_if2
// ./bb_spi_x_test
#include <stdio.h>
#include "pigpiod_if2.h"
#define CE0 5
#define CE1 6
#define MISO 13
#define MOSI 19
#define SCLK 12
int main(int argc, char *argv[])
{
int i, pi, count, set_val, read_val;
unsigned char inBuf[3];
char cmd1[] = {0, 0};
char cmd2[] = {12, 0};
char cmd3[] = {1, 128, 0};
if ((pi = pigpio_start(0, 0)) < 0)
{
fprintf(stderr, "pigpio initialisation failed (%d).0, pi);
return 1;
}
bb_spi_open(pi, CE0, MISO, MOSI, SCLK, 10000, 0); // MCP4251 DAC
bb_spi_open(pi, CE1, MISO, MOSI, SCLK, 20000, 3); // MCP3008 ADC
for (i=0; i<256; i++)
{
cmd1[1] = i;
count = bb_spi_xfer(pi, CE0, cmd1, (char *)inBuf, 2); // > DAC
if (count == 2)
{
count = bb_spi_xfer(pi, CE0, cmd2, (char *)inBuf, 2); // < DAC
if (count == 2)
{
set_val = inBuf[1];
count = bb_spi_xfer(pi, CE1, cmd3, (char *)inBuf, 3); // < ADC
if (count == 3)
{
read_val = ((inBuf[1]&3)<<8) | inBuf[2];
printf("%d %d0, set_val, read_val);
}
}
}
}
bb_spi_close(pi, CE0);
bb_spi_close(pi, CE1);
pigpio_stop(pi);
}
The Pi has two SPI peripherals: main and auxiliary.
The main SPI has two chip selects (channels), the auxiliary has three.
The auxiliary SPI is available on all models but the A and B.
The GPIO used are given in the following table.
MISO MOSI SCLK CE0 CE1 CE2
Main SPI 9 10 11 8 7 -
Aux SPI 19 20 21 18 17 16
pi: >=0 (as returned by pigpio_start).
spi_channel: 0-1 (0-2 for the auxiliary SPI).
baud: 32K-125M (values above 30M are unlikely to work).
spi_flags: see below.
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.
spi_flags consists of the least significant 22 bits.
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
b b b b b b R T n n n n W A u2 u1 u0 p2 p1 p0 m m
mm defines the SPI mode.
Warning: modes 1 and 3 do not appear to work on the auxiliary SPI.
Mode POL PHA
0 0 0
1 0 1
2 1 0
3 1 1
px is 0 if CEx is active low (default) and 1 for active high.
ux is 0 if the CEx GPIO is reserved for SPI (default) and 1 otherwise.
A is 0 for the main SPI, 1 for the auxiliary SPI.
W is 0 if the device is not 3-wire, 1 if the device is 3-wire. Main SPI only.
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. Main SPI only.
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 only.
R is 1 if the least significant bit is received on MISO first, the default (0) receives the most significant bit first. Auxiliary SPI only.
bbbbbb defines the word size in bits (0-32). The default (0) sets 8 bits per word. Auxiliary SPI only.
The spi_read, spi_write, and spi_xfer functions transfer data packed into 1, 2, or 4 bytes according to the word size in bits.
For bits 1-8 there will be one byte per character.
For bits 9-16 there will be two bytes per character.
For bits 17-32 there will be four bytes per character.
Multi-byte transfers are made in least significant byte first order.
E.g. to transfer 32 11-bit words buf should contain 64 bytes and count should be 64.
E.g. to transfer the 14 bit value 0x1ABC send the bytes 0xBC followed by 0x1A.
The other bits in flags should be set to zero.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to spi_open.
Returns 0 if OK, otherwise PI_BAD_HANDLE.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to spi_open.
buf: an array to receive the read data bytes.
count: the number of bytes to read.
Returns the number of bytes transferred if OK, otherwise PI_BAD_HANDLE, PI_BAD_SPI_COUNT, or PI_SPI_XFER_FAILED.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to spi_open.
buf: the data bytes to write.
count: the number of bytes to write.
Returns the number of bytes transferred if OK, otherwise PI_BAD_HANDLE, PI_BAD_SPI_COUNT, or PI_SPI_XFER_FAILED.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to spi_open.
txBuf: the data bytes to write.
rxBuf: the received data bytes.
count: the number of bytes to transfer.
Returns the number of bytes transferred if OK, otherwise PI_BAD_HANDLE, PI_BAD_SPI_COUNT, or PI_SPI_XFER_FAILED.
pi: >=0 (as returned by pigpio_start).
ser_tty: the serial device to open.
baud: the baud rate in bits per second, see below.
ser_flags: 0.
Returns a handle (>=0) if OK, otherwise PI_NO_HANDLE, or PI_SER_OPEN_FAILED.
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.
No flags are currently defined. This parameter should be set to zero.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to serial_open.
Returns 0 if OK, otherwise PI_BAD_HANDLE.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to serial_open.
Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_SER_WRITE_FAILED.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to serial_open.
Returns the read byte (>=0) if OK, otherwise PI_BAD_HANDLE, PI_SER_READ_NO_DATA, or PI_SER_READ_FAILED.
If no data is ready PI_SER_READ_NO_DATA is returned.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to serial_open.
buf: the array of bytes to write.
count: the number of bytes to write.
Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, or PI_SER_WRITE_FAILED.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to serial_open.
buf: an array to receive the read data.
count: the maximum number of bytes to read.
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.
If no data is ready zero is returned.
pi: >=0 (as returned by pigpio_start).
handle: >=0, as returned by a call to serial_open.
Returns the number of bytes of data available (>=0) if OK, otherwise PI_BAD_HANDLE.
It returns a single integer value.
pi: >=0 (as returned by pigpio_start).
arg1: >=0
arg2: >=0
argx: extra (byte) arguments
argc: number of extra arguments
Returns >= 0 if OK, less than 0 indicates a user defined error.
It differs from custom_1 in that it returns an array of bytes rather than just an integer.
The return value is an integer indicating the number of returned bytes.
pi: >=0 (as returned by pigpio_start).
arg1: >=0
argc: extra (byte) arguments
count: number of extra arguments
retBuf: buffer for returned data
retMax: maximum number of bytes to return
Returns >= 0 if OK, less than 0 indicates a user defined error.
Note, the number of returned bytes will be retMax or less.
pi: >=0 (as returned by pigpio_start).
pad: 0-2, the pad to get.
Returns the pad drive strength if OK, otherwise PI_BAD_PAD.
Pad GPIO
0 0-27
1 28-45
2 46-53
Example
strength = get_pad_strength(pi, 0); // get pad 0 strength
pi: >=0 (as returned by pigpio_start).
pad: 0-2, the pad to set.
padStrength: 1-16 mA.
Returns 0 if OK, otherwise PI_BAD_PAD, or PI_BAD_STRENGTH.
Pad GPIO
0 0-27
1 28-45
2 46-53
Example
set_pad_strength(pi, 0, 10); // set pad 0 strength to 10 mA
pi: >=0 (as returned by pigpio_start).
scriptName: the name of the script, only alphanumeric characters,
'-' and '_' are allowed in the name.
scriptString: the string to pass to the script.
The exit status of the system call is returned if OK, otherwise PI_BAD_SHELL_STATUS.
scriptName must exist in /opt/pigpio/cgi and must be executable.
The returned exit status is normally 256 times that set by the shell script exit function. If the script can't be found 32512 will be returned.
The following table gives some example returned statuses.
Script exit status Returned system call status
1 256
5 1280
10 2560
200 51200
script not found 32512
Example
// pass two parameters, hello and world
status = shell_(pi, "scr1", "hello world");
// pass three parameters, hello, string with spaces, and world
status = shell_(pi, "scr1", "hello 'string with spaces' world");
// pass one parameter, hello string with spaces world
status = shell_(pi, "scr1", "
pi: >=0 (as returned by pigpio_start).
file: the file to open.
mode: the file open mode.
Returns a handle (>=0) if OK, otherwise PI_NO_HANDLE, PI_NO_FILE_ACCESS, PI_BAD_FILE_MODE, PI_FILE_OPEN_FAILED, or PI_FILE_IS_A_DIR.
File
A file may only be opened if permission is granted by an entry in /opt/pigpio/access. This is intended to allow remote access to files in a more or less controlled manner.
Each entry in /opt/pigpio/access takes the form of a file path which may contain wildcards followed by a single letter permission. The permission may be R for read, W for write, U for read/write, and N for no access.
Where more than one entry matches a file the most specific rule applies. If no entry matches a file then access is denied.
Suppose /opt/pigpio/access contains the following entries
/home/* n
/home/pi/shared/dir_1/* w
/home/pi/shared/dir_2/* r
/home/pi/shared/dir_3/* u
/home/pi/shared/dir_1/file.txt n
Files may be written in directory dir_1 with the exception of file.txt.
Files may be read in directory dir_2.
Files may be read and written in directory dir_3.
If a directory allows read, write, or read/write access then files may be created in that directory.
In an attempt to prevent risky permissions the following paths are ignored in /opt/pigpio/access.
a path containing ..
a path containing only wildcards (*?)
a path containing less than two non-wildcard parts
Mode
The mode may have the following values.
Macro Value Meaning
PI_FILE_READ 1 open file for reading
PI_FILE_WRITE 2 open file for writing
PI_FILE_RW 3 open file for reading and writing
The following values may be or'd into the mode.
Macro Value Meaning
PI_FILE_APPEND 4 Writes append data to the end of the file
PI_FILE_CREATE 8 The file is created if it doesn't exist
PI_FILE_TRUNC 16 The file is truncated
Newly created files are owned by root with permissions owner read and write.
Example
#include <stdio.h>
#include <pigpiod_if2.h>
int main(int argc, char *argv[])
{
int pi, handle, c;
char buf[60000];
pi = pigpio_start(NULL, NULL);
if (pi < 0) return 1;
// assumes /opt/pigpio/access contains the following line
// /ram/*.c r
handle = file_open(pi, "/ram/pigpio.c", PI_FILE_READ);
if (handle >= 0)
{
while ((c=file_read(pi, handle, buf, sizeof(buf)-1)))
{
buf[c] = 0;
printf("%s", buf);
}
file_close(pi, handle);
}
pigpio_stop(pi);
}
pi: >=0 (as returned by pigpio_start).
handle: >=0 (as returned by file_open).
Returns 0 if OK, otherwise PI_BAD_HANDLE.
Example
file_close(pi, handle);
pi: >=0 (as returned by pigpio_start).
handle: >=0 (as returned by file_open).
buf: the array of bytes to write.
count: the number of bytes to write.
Returns 0 if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, PI_FILE_NOT_WOPEN, or PI_BAD_FILE_WRITE.
Example
if (file_write(pi, handle, buf, 100) == 0)
{
// file written okay
}
else
{
// error
}
pi: >=0 (as returned by pigpio_start).
handle: >=0 (as returned by file_open).
buf: an array to receive the read data.
count: the maximum number of bytes to read.
Returns the number of bytes read (>0) if OK, otherwise PI_BAD_HANDLE, PI_BAD_PARAM, PI_FILE_NOT_ROPEN, or PI_BAD_FILE_WRITE.
Example
bytes = file_read(pi, handle, buf, sizeof(buf));
if (bytes >= 0)
{
// process read data
}
pi: >=0 (as returned by pigpio_start).
handle: >=0 (as returned by file_open).
seekOffset: the number of bytes to move. Positive offsets
move forward, negative offsets backwards.
seekFrom: one of PI_FROM_START (0), PI_FROM_CURRENT (1),
or PI_FROM_END (2).
Returns the new byte position within the file (>=0) if OK, otherwise PI_BAD_HANDLE, or PI_BAD_FILE_SEEK.
Example
file_seek(pi, handle, 123, PI_FROM_START); // Start plus 123
size = file_seek(pi, handle, 0, PI_FROM_END); // End, return size
pos = file_seek(pi, handle, 0, PI_FROM_CURRENT); // Current position
pi: >=0 (as returned by pigpio_start).
fpat: file pattern to match.
buf: an array to receive the matching file names.
count: the maximum number of bytes to read.
Returns the number of returned bytes if OK, otherwise PI_NO_FILE_ACCESS, or PI_NO_FILE_MATCH.
The pattern must match an entry in /opt/pigpio/access. The pattern may contain wildcards. See file_open.
NOTE
The returned value is not the number of files, it is the number of bytes in the buffer. The file names are separated by newline characters.
Example
#include <stdio.h>
#include <pigpiod_if2.h>
int main(int argc, char *argv[])
{
int pi, handle, c;
char buf[60000];
pi = pigpio_start(NULL, NULL);
if (pi < 0) return 1;
// assumes /opt/pigpio/access contains the following line
// /ram/*.c r
c = file_list(pi, "/ram/p*.c", buf, sizeof(buf));
if (c >= 0)
{
buf[c] = 0;
printf("%s", buf);
}
pigpio_stop(pi);
}
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
edge: RISING_EDGE, FALLING_EDGE, or EITHER_EDGE.
f: the callback function.
The function returns a callback id if OK, otherwise pigif_bad_malloc, pigif_duplicate_callback, or pigif_bad_callback.
The callback is called with the GPIO, edge, and tick, whenever the GPIO has the identified edge.
Parameter Value Meaning
GPIO 0-31 The GPIO which has changed state
edge 0-2 0 = change to low (a falling edge)
1 = change to high (a rising edge)
2 = no level change (a watchdog timeout)
tick 32 bit The number of microseconds since boot
WARNING: this wraps around from
4294967295 to 0 roughly every 72 minutes
The GPIO are sampled at a rate set when the pigpio daemon is started (default 5 us).
The number of samples per second is given in the following table.
samples
per sec
1 1,000,000
2 500,000
sample 4 250,000
rate 5 200,000
(us) 8 125,000
10 100,000
GPIO level changes shorter than the sample rate may be missed.
The daemon software which generates the callbacks is triggered 1000 times per second. The callbacks will be called once per level change since the last time they were called. i.e. The callbacks will get all level changes but there will be a latency.
If you want to track the level of more than one GPIO do so by maintaining the state in the callback. Do not use gpio_read. Remember the event that triggered the callback may have happened several milliseconds before and the GPIO may have changed level many times since then.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
edge: RISING_EDGE, FALLING_EDGE, or EITHER_EDGE.
f: the callback function.
userdata: a pointer to arbitrary user data.
The function returns a callback id if OK, otherwise pigif_bad_malloc, pigif_duplicate_callback, or pigif_bad_callback.
The callback is called with the GPIO, edge, tick, and the userdata pointer, whenever the GPIO has the identified edge.
Parameter Value Meaning
GPIO 0-31 The GPIO which has changed state
edge 0-2 0 = change to low (a falling edge)
1 = change to high (a rising edge)
2 = no level change (a watchdog timeout)
tick 32 bit The number of microseconds since boot
WARNING: this wraps around from
4294967295 to 0 roughly every 72 minutes
userdata pointer Pointer to an arbitrary object
callback_id: >=0, as returned by a call to callback or callback_ex.
The function returns 0 if OK, otherwise pigif_callback_not_found.
pi: >=0 (as returned by pigpio_start).
user_gpio: 0-31.
edge: RISING_EDGE, FALLING_EDGE, or EITHER_EDGE.
timeout: >=0.
The function returns when the edge occurs or after the timeout.
Do not use this function for precise timing purposes, the edge is only checked 20 times a second. Whenever you need to know the accurate time of GPIO events use a callback function.
The function returns 1 if the edge occurred, otherwise 0.
This peripheral allows the Pi to act as a hardware slave device on an I2C or SPI bus.
This is not a bit bang version and as such is OS timing independent. The bus timing is handled directly by the chip.
The output process is simple. You simply append data to the FIFO buffer on the chip. This works like a queue, you add data to the queue and the master removes it.
I can't get SPI to work properly. I tried with a control word of 0x303 and swapped MISO and MOSI.
The function sets the BSC mode, writes any data in the transmit buffer to the BSC transmit FIFO, and copies any data in the BSC receive FIFO to the receive buffer.
pi: >=0 (as returned by pigpio_start).
bscxfer: a structure defining the transfer.
typedef struct
{
uint32_t control; // Write
int rxCnt; // Read only
char rxBuf[BSC_FIFO_SIZE]; // Read only
int txCnt; // Write
char txBuf[BSC_FIFO_SIZE]; // Write
} bsc_xfer_t;
To start a transfer set control (see below), copy the bytes to be added to the transmit FIFO (if any) to txBuf and set txCnt to the number of copied bytes.
Upon return rxCnt will be set to the number of received bytes placed in rxBuf.
The returned function value is the status of the transfer (see below).
If there was an error the status will be less than zero (and will contain the error code).
The most significant word of the returned status contains the number of bytes actually copied from txBuf to the BSC transmit FIFO (may be less than requested if the FIFO already contained untransmitted data).
Note that the control word sets the BSC mode. The BSC will stay in that mode until a different control word is sent.
GPIO used for models other than those based on the BCM2711.
SDA SCL MOSI SCLK MISO CE
I2C 18 19 - - - -
SPI - - 18 19 20 21
GPIO used for models based on the BCM2711 (e.g. the Pi4B).
SDA SCL MOSI SCLK MISO CE
I2C 10 11 - - - -
SPI - - 10 11 9 8
When a zero control word is received the used GPIO will be reset to INPUT mode.
control consists of the following bits.
22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
a a a a a a a - - IT HC TF IR RE TE BK EC ES PL PH I2 SP EN
Bits 0-13 are copied unchanged to the BSC CR register. See pages 163-165 of the Broadcom peripherals document for full details.
aaaaaaa defines the I2C slave address (only relevant in I2C
mode)
IT invert transmit status flags
HC enable host control
TF enable test FIFO
IR invert receive status flags
RE enable receive
TE enable transmit
BK abort operation and clear FIFOs
EC send control register as first I2C byte
ES send status register as first I2C byte
PL set SPI polarity high
PH set SPI phase high
I2 enable I2C mode
SP enable SPI mode
EN enable BSC peripheral
The returned status has the following format
20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
S S S S S R R R R R T T T T T RB TE RF TF RE TB
Bits 0-15 are copied unchanged from the BSC FR register. See pages 165-166 of the Broadcom peripherals document for full details.
SSSSS number of bytes successfully copied to transmit FIFO
RRRRR number of bytes in receieve FIFO
TTTTT number of bytes in transmit FIFO
RB receive busy
TE transmit FIFO empty
RF receive FIFO full
TF transmit FIFO full
RE receive FIFO empty
TB transmit busy
The following example shows how to configure the BSC peripheral as an I2C slave with address 0x13 and send four bytes.
Example
bsc_xfer_t xfer;
xfer.control = (0x13<<16) | 0x305;
memcpy(xfer.txBuf, "ABCD", 4);
xfer.txCnt = 4;
status = bsc_xfer(pi, &xfer);
if (status >= 0)
{
// process transfer
}
This function is not available on the BCM2711 (e.g.as used in the Pi4B).
The data bytes (if any) are written to the BSC transmit FIFO and the bytes in the BSC receive FIFO are returned.
pi: >=0 (as returned by pigpio_start).
i2c_addr: 0-0x7F.
bscxfer: a structure defining the transfer.
typedef struct
{
uint32_t control; // N/A
int rxCnt; // Read only
char rxBuf[BSC_FIFO_SIZE]; // Read only
int txCnt; // Write
char txBuf[BSC_FIFO_SIZE]; // Write
} bsc_xfer_t;
txCnt is set to the number of bytes to be transmitted, possibly zero. The data itself should be copied to txBuf.
Any received data will be written to rxBuf with rxCnt set.
See bsc_xfer for details of the returned status value.
If there was an error the status will be less than zero (and will contain the error code).
Note that an i2c_address of 0 may be used to close the BSC device and reassign the used GPIO as inputs.
pi: >=0 (as returned by pigpio_start).
event: 0-31.
f: the callback function.
The function returns a callback id if OK, otherwise pigif_bad_malloc, pigif_duplicate_callback, or pigif_bad_callback.
The callback is called with the event id, and tick, whenever the event occurs.
pi: >=0 (as returned by pigpio_start).
event: 0-31.
f: the callback function.
userdata: a pointer to arbitrary user data.
The function returns a callback id if OK, otherwise pigif_bad_malloc, pigif_duplicate_callback, or pigif_bad_callback.
The callback is called with the event id, the tick, and the userdata pointer whenever the event occurs.
callback_id: >=0, as returned by a call to event_callback or
event_callback_ex.
The function returns 0 if OK, otherwise pigif_callback_not_found.
pi: >=0 (as returned by pigpio_start).
event: 0-31.
timeout: >=0.
The function returns when the event occurs or after the timeout.
The function returns 1 if the event occurred, otherwise 0.
pi: >=0 (as returned by pigpio_start).
event: 0-31.
Returns 0 if OK, otherwise PI_BAD_EVENT_ID.
An event is a signal used to inform one or more consumers to start an action. Each consumer which has registered an interest in the event (e.g. by calling event_callback) will be informed by a callback.
One event, PI_EVENT_BSC (31) is predefined. This event is auto generated on BSC slave activity.
The meaning of other events is arbitrary.
Note that other than its id and its tick there is no data associated with an event.
The number of microseconds level changes are reported for once a noise filter has been triggered (by steady microseconds of a stable level).
A convenient way to set bit n is to or in (1<<n).
e.g. to select bits 5, 9, 23 you could use (1<<5) | (1<<9) | (1<<23).
typedef struct
{
uint32_t control; // Write
int rxCnt; // Read only
char rxBuf[BSC_FIFO_SIZE]; // Read only
int txCnt; // Write
char txBuf[BSC_FIFO_SIZE]; // Write
} bsc_xfer_t;
callback
callback_ex
event_callback
event_callback_ex
The id is passed to callback_cancel or event_callback_cancel to cancel the callback.
typedef void (*CBFunc_t)
(int pi, unsigned user_gpio, unsigned level, uint32_t tick);
typedef void (*CBFuncEx_t)
(int pi, unsigned user_gpio, unsigned level, uint32_t tick, void * userdata);
#define PI_MIN_WAVE_DATABITS 1
#define PI_MAX_WAVE_DATABITS 32
The number may vary between 0 and range (default 255) where 0 is off and range is fully on.
RISING_EDGE 0
FALLING_EDGE 1
EITHER_EDGE. 2
typedef void (*evtCBFunc_t)
(int pi, unsigned event, uint32_t tick);
typedef void (*evtCBFuncEx_t)
(int pi, unsigned event, uint32_t tick, void *userdata);
There are 54 General Purpose Input Outputs (GPIO) named GPIO0 through GPIO53.
They are split into two banks. Bank 1 consists of GPIO0 through GPIO31. Bank 2 consists of GPIO32 through GPIO53.
All the GPIO which are safe for the user to read and write are in bank 1. Not all GPIO in bank 1 are safe though. Type 1 boards have 17 safe GPIO. Type 2 boards have 21. Type 3 boards have 26.
See get_hardware_revision.
The user GPIO are marked with an X in the following table.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Type 1 X X - - X - - X X X X X - - X X
Type 2 - - X X X - - X X X X X - - X X
Type 3 X X X X X X X X X X X X X X
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Type 1 - X X - - X X X X X - - - - - -
Type 2 - X X - - - X X X X - X X X X X
Type 3 X X X X X X X X X X X X - - - -
typedef struct
{
uint32_t gpioOn;
uint32_t gpioOff;
uint32_t usDelay;
} gpioPulse_t;
typedef void *(gpioThreadFunc_t) (void *);
file_open
i2c_open
notify_open
serial_open
spi_open
PI_OFF 0
PI_ON 1
PI_CLEAR 0
PI_SET 1
PI_LOW 0
PI_HIGH 1
There is one exception. If a watchdog expires on a GPIO the level will be reported as PI_TIMEOUT. See set_watchdog.
PI_TIMEOUT 2
PI_INPUT 0
PI_OUTPUT 1
PI_ALT0 4
PI_ALT1 5
PI_ALT2 6
PI_ALT3 7
PI_ALT4 3
PI_ALT5 2
2. The mode of waveform transmission.
PI_WAVE_MODE_ONE_SHOT 0
PI_WAVE_MODE_REPEAT 1
PI_WAVE_MODE_ONE_SHOT_SYNC 2
PI_WAVE_MODE_REPEAT_SYNC 3
3. A file open mode.
PI_FILE_READ 1
PI_FILE_WRITE 2
PI_FILE_RW 3
The following values can be or'd into the mode.
PI_FILE_APPEND 4
PI_FILE_CREATE 8
PI_FILE_TRUNC 16
Pad GPIO
0 0-27
1 28-45
2 46-53
PI_PUD_OFF 0
PI_PUD_DOWN 1
PI_PUD_UP 2
PI_SERVO_OFF 0
PI_MIN_SERVO_PULSEWIDTH 500
PI_MAX_SERVO_PULSEWIDTH 2500
#define PI_HW_PWM_RANGE 1000000
#define PI_HW_PWM_MIN_FREQ 1
#define PI_HW_PWM_MAX_FREQ 125000000
#define PI_HW_PWM_MAX_FREQ_2711 187500000
PI_MIN_DUTYCYCLE_RANGE 25
PI_MAX_DUTYCYCLE_RANGE 40000
PI_FROM_START 0
PI_FROM_CURRENT 1
PI_FROM_END 2
The number of microseconds level changes must be stable for before reporting the level changed (set_glitch_filter) or triggering the active part of a noise filter (set_noise_filter).
#define PI_MIN_WAVE_HALFSTOPBITS 2
#define PI_MAX_WAVE_HALFSTOPBITS 8
PI_MIN_WDOG_TIMEOUT 0
PI_MAX_WDOG_TIMEOUT 60000
See gpio.
A pointer to arbitrary user data. This may be used to identify the instance.
You must ensure that the pointer is in scope at the time it is processed. If it is a pointer to a global this is automatic. Do not pass the address of a local variable. If you want to pass a transient object then use the following technique.
In the calling function:
user_type *userdata;
user_type my_userdata;
userdata = malloc(sizeof(user_type));
*userdata = my_userdata;
In the receiving function:
user_type my_userdata = *(user_type*)userdata;
free(userdata);
wave_add_new
wave_add_generic
wave_add_serial
wave_send_once
wave_send_repeat
typedef enum
{
pigif_bad_send = -2000,
pigif_bad_recv = -2001,
pigif_bad_getaddrinfo = -2002,
pigif_bad_connect = -2003,
pigif_bad_socket = -2004,
pigif_bad_noib = -2005,
pigif_duplicate_callback = -2006,
pigif_bad_malloc = -2007,
pigif_bad_callback = -2008,
pigif_notify_failed = -2009,
pigif_callback_not_found = -2010,
pigif_unconnected_pi = -2011,
pigif_too_many_pis = -2012,
} pigifError_t;
joan@abyz.me.uk
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