i2c-decaffeinated

i2c

Bindings for i2c-dev. Plays well with Raspberry Pi and Beaglebone.

This version removes all dependencies on CoffeeScript due to the CoffeeScript compiler using labeled declarations which fail ES6 module validation and Acorn validation.

Install

$ npm install i2c-decaffeinated

Usage

 
var i2c = require('i2c');
var address = 0x18;
var wire = new i2c(address, {device: '/dev/i2c-1'}); // point to your i2c address, debug provides REPL interface
 
wire.scan(function(err, data) {
  // result contains an array of addresses
});
 
wire.writeByte(byte, function(err) {});
 
wire.writeBytes(command, [byte0, byte1], function(err) {});
 
wire.readByte(function(err, res) { // result is single byte })
 
wire.readBytes(command, length, function(err, res) {
  // result contains a buffer of bytes
});
 
wire.on('data', function(data) {
  // result for continuous stream contains data buffer, address, length, timestamp
});
 
wire.stream(command, length, delay); // continuous stream, delay in ms
 
 
// plain read/write
 
wire.write([byte0, byte1], function(err) {});
 
wire.read(length, function(err, res) {
  // result contains a buffer of bytes
});
 
 

Raspberry Pi Setup

$ sudo vi /etc/modules

Add these two lines

i2c-bcm2708
i2c-dev

$ sudo vi /etc/modprobe.d/raspi-blacklist.conf

Comment out blacklist i2c-bcm2708

#blacklist i2c-bcm2708

Load kernel module

$ sudo modprobe i2c-bcm2708
$ sudo modprobe i2c-dev

Make device writable

sudo chmod o+rw /dev/i2c*

Install gcc 4.8 (required for Nan)

sudo apt-get install gcc-4.8 g++-4.8
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.6 60 --slave /usr/bin/g++ g++ /usr/bin/g++-4.6
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8 40 --slave /usr/bin/g++ g++ /usr/bin/g++-4.8
sudo update-alternatives --config gcc
 

Set correct device for version

 
new i2c(address, device: '/dev/i2c-0') // rev 1
new i2c(address, device: '/dev/i2c-1') // rev 2
 

Beaglebone

$ ntpdate -b -s -u pool.ntp.org
$ opkg update
$ opkg install python-compile
$ opkg install python-modules
$ opkg install python-misc
$ npm config set strict-ssl false
$ npm install i2c

Node 0.11 and under

npm install i2c@0.1.8

Projects using i2c

• bonescript https://github.com/jadonk/bonescript/
• ADXL345 https://github.com/timbit123/ADXL345
• HMC6343 https://github.com/omcaree/node-hmc6343
• LSM303 https://github.com/praneshkmr/node-lsm303
• MPU6050 https://github.com/jstapels/mpu6050/
• MCP3424 https://github.com/x3itsolutions/mcp3424
• blinkm https://github.com/korevec/blinkm
• click boards https://github.com/TheThingSystem/node-click-boards
• more: https://www.npmjs.org/browse/depended/i2c

Contributors

Thanks to @alphacharlie for Nan rewrite!

Questions?

http://www.twitter.com/korevec