The Rust i2cdev crate seeks to provide full access to the Linux i2cdev
driver interface in Rust without the need to wrap any C code or directly make
low-level system calls. The documentation for the i2cdev interace can
be found at https://www.kernel.org/doc/Documentation/i2c/dev-interface and
in the lm-sensors projects.
Device driver developers should consider building on top of the embedded-hal traits rather than directly coupling to this library. An implementation of those generic traits for Linux can be found in linux-embedded-hal which, at present, uses this crate as the backend for I2C.
The source includes an example of using the library to talk to a Wii Nunchuck (which has an i2c interface). Go View the Example.
Here's a real quick example showing the guts of how you create device and start talking to it...
extern crate i2cdev;
use std::thread;
use std::time::Duration;
use i2cdev::core::*;
use i2cdev::linux::{LinuxI2CDevice, LinuxI2CError};
const NUNCHUCK_SLAVE_ADDR: u16 = 0x52;
// real code should probably not use unwrap()
fn i2cfun() -> Result<(), LinuxI2CError> {
let mut dev = LinuxI2CDevice::new("/dev/i2c-1", NUNCHUCK_SLAVE_ADDR)?;
// init sequence
dev.smbus_write_byte_data(0xF0, 0x55)?;
dev.smbus_write_byte_data(0xFB, 0x00)?;
thread::sleep(Duration::from_millis(100));
loop {
let mut buf: [u8; 6] = [0; 6];
dev.smbus_write_byte(0x00).unwrap();
thread::sleep(Duration::from_millis(10));
dev.read(&mut buf).unwrap();
println!("Reading: {:?}", buf);
}
}In addition to the Read/Write traits, the following methods are available via the I2CDevice trait.
The following features are implemented and planned for the library:
- Implement the Read trait
- Implement the Write trait
- Implement SMBus Methods
- Add Tests/Example for SMBus Methods
- Add sensor library for handy sensors (and examples)
- Add higher-level APIs/Macros for simplifying access to devices with large register sets
- Add Support for Non-SMBus ioctl methods
- Add examples for non-smbus ioctl methods
- Unit Testing
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. See https://github.com/japaric/rust-cross for pointers.
Copyright (c) 2015, Paul Osborne <ospbau@gmail.com>
Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
http://www.apache.org/license/LICENSE-2.0> or the MIT license
<LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
option. This file may not be copied, modified, or distributed
except according to those terms.