I2C library

Provides functionality for I2C master communication. It supports 100 or 400 kbits modes. Initialize:

var i2c = require('i2c');

Open I2C instance

open(baudrate);

Function open I2C channel with specified baudrate.

Number baudrate - baudrate specifies communication speed. Use 100 or 400.

Write data

write(address,data,callback(err));

Number address - 7 bit of address. This address is internally shifted to the left.

ByteBuffer|String data - Data can be type of String, ByteBuffer. String format is array of hex. values, for example. "00FF09B8"

Function callback - this function will be invoked when data is sent.

String err - null or error message.

Write bulk

writeBulk(address, data, callback(err));

Function writes bulk of data.

Number address - 7 bit of address. This address is internally shifted to the left.

Array data - array of arrays. When you need make a few separated writes, you can create array. For example, we need write two registers. First reg. 2A, value EF and second reg. 15, value 0A.

var data = [[0x2A,0xEF],[0x15,0x0A]];
i2c.writeBulk(0x20,data,function(err){.....});

Function calback

Read

read(address,num_of_bytes,callback(data));

Function read data from I2C.

Number address - 7 bit of address. This address is internally shifted to the left.

Number num of bytes - number of bytes which will be read.

Function callback - function will be invoked when data is read.

Close

close();

Example I2C

var i2c = require("i2c");
var sys = require("system");

i2c.open(400);

i2c.write(0x20,"12",function(err){
    if (err) sys.println("err:"+err);
    else {
        i2c.read(0x20,10,function(data){
            if (data!=null) {
                sys.println("data:"+data.toString());
            }
        });
    }  
})