Awesome
gpio
bindings for linux gpiod, a user space interface for general purpose IO control
Installation
ensure the development dependencies are installed: sudo apt install libgpiod-dev
-
Add the dependency to your
shard.yml
:dependencies: gpio: github: spider-gazelle/gpio.cr
-
Run
shards install
Usage
You can list the various chips available on a system by running gpioinfo
this will list chips and IO line details.
require "gpio"
GPIO.default_consumer = "my app"
all_chips = GPIO::Chip.all
# or if you know the name
chip = GPIO::Chip.new "gpiochip0"
chip.lines
# take control of a line and set it's state
line = chip.line(5)
line.name
line.request_output
line.set_high
line.high? # => true
sleep 0.5
line.set_low
line.high? # => false
# release the line once finished using
# this will also happen on garbage collection
line.release
You can also configure the line for input and wait for input events to occur
require "gpio"
GPIO.default_consumer = "my app"
chip = GPIO::Chip.new "gpiochip0"
line = chip.line 0
# blocks here until this line is released
# so you might want to do this in a spawn etc
line.on_input_change do |input_is|
case input_is
in .rising?
puts "input is high"
in .falling?
puts "input is low"
end
end