I2C Port

BeagleBone has in-built I2C port functionality and OctalBoneScript provides a way to access it without loading any aditional cape. These functions are essentially wrapper around I2C library.

We recommned that you use these functions instead of the library because these functions automatically performs required pinMode on the pins to make them ready for serial communication.

Please note that original bonescript functions like i2cOpen are deprecated and you must use i2c.open like functions documented below.

i2c.open(path, address, handler[data], callback[error|null, wire])

• path is i2c port path for BeagleBone. vaild values are /dev/i2c-1, /dev/i2c-1a and /dev/i2c-2
• address is hexadecimal address identifier eg. 0x18
• handler is called with data as first arguemnt when data is received on I2C port
• callback first argument is verror object if there is error opening port, null otherwise. second argument is same object you get after calling new i2c function of the library as described here: https://github.com/kelly/node-i2c#usage

Example

var b = require('octalbonescript'); //load the library

b.i2c.open('/dev/i2c-1', 0x018, function(data){
  console.log(data);
}, function(error, wire){
  if(error){
    console.error(error.message);
    return;
  }
  // 'wire' is object which can be used to call other functions on it 
  // as per described here https://github.com/kelly/node-i2c#usage
  // you can call writeByte, readByte etc functions on 'wire'.
});

i2c.enable(path, callback)

• this is optional function if you just want to enable i2c port. It prepares pins used by i2c port by calling pinMode on them

Other functions

• this library provides wrapper functions i2c.writeByte, i2c.writeBytes, i2c.readByte, i2c.write, i2c.stream, and i2c.read.
• all these functions are same as functions described here: https://github.com/kelly/node-i2c#usage but they all have first argument as path of i2c port and rest all argument and functionalities are same.

Example

var b = require('octalbonescript'); //load the library

b.i2c.writeByte('/dev/i2c-1', byte, function(err){
  if(err){
    console.error(err);
    return;
  }
  // note that first argument is path of i2c port and other arguments are same.
});