rust-sysfs-gpio

• API Documentation

rust-sysfs-gpio is a rust library/crate providing access to the Linux sysfs GPIO interface (https://www.kernel.org/doc/Documentation). It seeks to provide an API that is safe, convenient, and efficient.

Many devices such as the Raspberry Pi or Beaglebone Black provide userspace access to a number of GPIO peripherals. The standard kernel API for providing access to these GPIOs is via sysfs.

Install/Use

To use sysfs_gpio, first add this to your Cargo.toml:

toml [dependencies] sysfs_gpio = "0.4"

Then, add this to your crate root:

rust extern crate sysfs_gpio;

Example/API

Blinking an LED:

```rust extern crate sysfs_gpio;

use sysfsgpio::{Direction, Pin}; use std::thread::sleepms;

fn main() { let myled = Pin::new(127); // number depends on chip, etc. myled.withexported(|| { loop { myled.setvalue(0).unwrap(); sleepms(200); myled.setvalue(1).unwrap(); sleep_ms(200); } }).unwrap(); } ```

More Examples:

• Blink an LED
• Poll a GPIO Input
• Receive interrupt on GPIO Change

Features

The following features are planned for the library:

• [x] Support for exporting a GPIO
• [x] Support for unexporting a GPIO
• [x] Support for setting the direction of a GPIO (in/out)
• [x] Support for reading the value of a GPIO input
• [x] Support for writing the value of a GPIO output
• [ ] Support for configuring whether a pin is active low/high
• [x] Support for configuring interrupts on GPIO
• [x] Support for polling on GPIO with configured interrupt

Cross Compiling

Most likely, the machine you are running on is not your development machine (although it could be). In those cases, you will need to cross-compile. The following basic instructions should work for the raspberry pi or beaglebone black:

1. Install rust and cargo
2. Install an appropriate cross compiler. On an Ubuntu system, this can be done by doing sudo apt-get install g++-arm-linux-gnueabihf.
3. Build or install rust for your target. For some hints, check out https://github.com/japaric/rust-cross.
4. Tell cargo how to link by adding the lines below to your ~/.cargo/config file.
5. Run your build cargo build --target=arm-unknown-linux-gnueabihf.

Running the Example

Cross-compiling can be done by specifying an appropriate target. You can then move that to your device by whatever means and run it.

$ cargo build --target=arm-unknown-linux-gnueabihf --example blinky $ scp target/arm-unknown-linux-gnueabihf/debug/examples/blinky ...

License

``` Copyright (c) 2015, Paul Osborne ospbau@gmail.com

Licensed under the Apache License, Version 2.0 or the MIT license , at your option. This file may not be copied, modified, or distributed except according to those terms. ```