gpiodWiringPi

A quick and dirty replication of the Arduino "wiring" GPIO syntax for RPI

Not much more to say. It provides the following functions:

• void pinMode(int pin, int direction)
• void digitalWrite(int pin, int value)
• int digitalRead(int pin)

It uses the fairly recent gpiod and libgpiod functionality of linux under the hood. It should be as simple as including gpiodWiring.h and gpioWiring.c into your project.

Examples

gpio.c

This one just uses a simple for loop to toggle the pin high and low at 1 millisecond intervals

To compile:

gcc -I.. gpio.c ../gpiodWiring.c -o gpio -lgpiod

To run:

./gpio

rt_gpio.c

I created this one to use high priority threads (I am using a RT_PREEMPT kernel to get the best possible GPIO timing on an RPI4 for a stepper motor controller). My anecdotal testing with an oscilloscope shows that I can get about 25 microsecond accuracy with this technique (with the caveat that nothing else is running on the device).

To compile:

gcc -I.. rt_gpio.c ../gpiodWiring.c -o rt_gpio -lgpiod -lpthread

To run (NOTE: this has to be run as sudo because I couldn't figure out how to get the high priority threads without it):

sudo ./rt_gpio