var i2c = require('i2c');
var address = 0x18;
var wire = new i2c(address, {device: '/dev/i2c-1', debug: true}); // 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

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