IoT.js-API-I2C.md

Platform Support

The following shows I2C module APIs available for each platform.

	Linux (Ubuntu)	Raspbian (Raspberry Pi)	NuttX (STM32F4-Discovery)
i2c.open	O	O	O
i2cbus.read	O	O	O
i2cbus.write	O	O	O
i2cbus.close	O	O	O

I2C

The I2C class supports the I2C protocol. I2C bus has two signals - SDA and SCL.

new I2C()

Returns with an I2C object.

Example

var I2C = require('i2c');

var i2c = new I2C();

i2c.open(configuration[, callback])

• configuration {Object} Configuration for open I2CBus.
  • device {string(linux)|number(NuttX)} Device path.
  • address {number} Device address.
• callback {Function}
  • err {Error|null}
• Returns: {Object} An instance of I2CBus.

Get I2CBus object with configuration.

Example

var I2C = require('i2c');

var i2c = new I2C();
var i2c_bus = i2c.open({device: '/dev/i2c-1', address: 0x23}, function(err) {
  if (err) {
    throw err;
  }
});

Class: I2CBus

i2cbus.read(length[, callback])

• length {number} Number of bytes to read.
• callback {Function}
  • err {Error|null}
  • res {Array} Array of bytes.

Read bytes from I2C device.

Example

var I2C = require('i2c');

var i2c = new I2C();
var i2c_bus = i2c.open({device: '/dev/i2c-1', address: 0x23});

i2c_bus.read(2, function(err, res) {
  if (!err) {
    console.log('read result: ' + res);
  }
});

i2cbus.write(bytes[, callback])

• bytes {Array} Array of bytes to write.
• callback {Function}
  • err {Error|null}

Write bytes to I2C device.

Example

var I2C = require('i2c');

var i2c = new I2C();
var i2c_bus = i2c.open({device: '/dev/i2c-1', address: 0x23});

i2c_bus.write([0x10], function(err) {
  if(!err) {
    console.log('write done');
  }
});

i2cbus.close()

Close I2C device.

Example

var I2C = require('i2c');

var i2c = new I2C();
var i2c_bus = i2c.open({device: '/dev/i2c-1', address: 0x23});

i2c_bus.close();