Driver for the Tessel relay module
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Driver for the relay-mono Tessel relay module. The hardware documentation for this module can be found here.

If you run into any issues you can ask for support on the Relay Module Forums.


npm install relay-mono


This relay module demo toggles both relay
channels every two seconds, logging the new
values to the console upon latching.

var tessel = require('tessel');
var relaylib = require('../'); 

var relay = relaylib.use(tessel.port['A']);  

// Wait for the module to connect
relay.on('ready', function relayReady () {
  console.log('Ready! Toggling relays...');
  setInterval(function toggle() {
    // Toggle relay channel 1
    relay.toggle(1, function toggleOneResult(err) {
      if (err) console.log("Err toggling 1", err);
    // Toggle relay channel 2
    relay.toggle(2, function toggleTwoResult(err) {
      if (err) console.log("Err toggling 2", err);
  }, 2000); // Every 2 seconds (2000ms)

// When a relay channel is set, it emits the 'latch' event
relay.on('latch', function(channel, value) {
  console.log('latch on relay channel ' + channel + ' switched to', value);


# relay.getState( relayChannel, callback(err, state) )
Gets the state of the specified relay channel: "true" for on and "false" for off.

# relay.toggle( relayChannel, callback(err) )
Switches the state of the specified relay channel: on if it's off; off if it's on.

# relay.turnOff( relayChannel, callback(err) )
Switches off the specified relay channel.

# relay.turnOn( relayChannel, callback(err) )
Switches on the specified relay channel.


# relay.on( 'error', callback(err) )
Emitted upon error.

# relay.on( 'latch', callback(channel, state))
Emitted when the latch state (boolean on or off ) is changed for a channel.

# relay.on( 'ready', callback() )
Emitted upon first successful communication between the Tessel and the module.


MIT or Apache 2.0, at your option