Code for a Tessel automated rotary welder

tessel-welder.js

var tessel = require('tessel');
var led = require('tessel-led');
var _ = require('underscore');

// Setup the Relay module on Port A
var relaylib = require('relay-mono');
var relay = relaylib.use(tessel.port['A']);

// Setup all switches & sensors to the GPIO
var gpio = tessel.port['GPIO'];
var swTurnTable = gpio.pin['G1'];
var btnWeld = gpio.pin['G2'];
var btnHome = gpio.pin['G3'];
var btnJog = gpio.pin['G6'];

// Add/Set 'Active' state for each GPIO object
swTurnTable.pressed = false;
btnWeld.pressed = false;
btnHome.pressed = false;
btnJog.pressed = false;

// Set pulldown switches/sensors (Tessel 'pull' functionality wasn't working when I did this project so I hardwired some physical pulldown resistors inline with my wiring)
//swTurnTable.pull('pulldown');
//btnWeld.pull('pulldown');
//btnHome.pull('pulldown');
//btnJog.pull('pulldown');

// Set all switches & sensors to input
swTurnTable.input();
btnWeld.input();
btnHome.input();
btnJog.input();

// underscore debounce function time
var timeDebounce = 100;

// Wait for the relay module to connect
relay.on('ready', function() {

    console.log('Ready to weld...');

    // Check for btnWeld... then start welding
    btnWeld.on('rise', _.debounce(function(time, type) {
        if ( btnWeld.read() ) {
            console.log('btnWeld was pressed!', type, time);
            btnWeld.pressed = true;
            weld();
        }
    }, debounceTime));

    // Check for btnHome... then home the turn table w/o welding
    btnHome.on('rise', _.debounce(function(time, type) {
        if ( btnHome.read() ) {
            console.log('btnHome was pressed!', type, time);
            btnHome.pressed = true;
            weld();
        }
    }, timeDebounce));

    // Check for btnJog... then jog the turn table w/o welding
    btnJog.on('change', _.debounce(function(time, type) {
        if ( btnJog.read() ) {
            console.log('btnJog was pressed!', type, time);
            btnJog.pressed = true;
            jog();
        }
        if ( !btnJog.read() && btnJog.pressed ) {
            console.log('btnJog was released!', type, time);
            btnJog.pressed = false;
            jog();
        }
    }, timeDebounce));

});

// When a relay 'latch' state is changed, it emits the 'latch' event
relay.on('latch', function(channel, value) {
    if ( channel == 1 ) {
        console.log('latch on turn table relay (channel ' + channel + ') switched to', value);
    }
    if ( channel == 2 ) {
        console.log('latch on welder relay (channel ' + channel + ') switched to', value);
    }
});


// Function to weld or home the turn table
function weld() {

    swTurnTable.on('rise', _.debounce(function(time, type) {

        if ( swTurnTable.read() && !swTurnTable.pressed ) {

            swTurnTable.pressed = true;

            console.log('on ' + type + ': ' + swTurnTable.read());

            swTurnTable.once('low', _.debounce(function(time, type) {

                led.green.hide();
                led.blue.hide();

                console.log('once ' + type + ': ' + swTurnTable.read());

                if ( btnWeld.pressed || btnHome.pressed ) {
                    relay.turnOff(1, function(err) {
                        if (err) console.log('Err turning off turn table relay 1', err);
                        btnHome.pressed = false;
                    });
                }
                if ( btnWeld.pressed ) {
                    relay.turnOff(2, function(err) {
                        if (err) console.log('Err turning off welder relay 2', err);
                        btnWeld.pressed = false;
                    });
                }

                swTurnTable.removeAllListeners();
                swTurnTable.pressed = false;

            }, timeDebounce));

        }

    }, timeDebounce));

    if ( btnWeld.pressed || btnHome.pressed ) {
        relay.turnOn(1, function(err) {
            if ( err ) {
                console.log('Err turning on turn table relay 1', err);
            }
            else {
                if ( btnWeld.pressed ) {
                    led.green.show();
                }
                if ( btnHome.pressed ) {
                    led.blue.show();
                }
            }
        });
    }

    if ( btnWeld.pressed ) {
        relay.turnOn(2, function(err) {
            if ( err ) {
                console.log('Err turning on welder relay 2', err);
            }
        });
    }

}


// Function to jog the weld turn table while btnJog is pressed
function jog() {
    if ( btnJog.pressed ) {
        relay.turnOn(1, function(err) {
            if (err) console.log("Err turning on relay 1", err);
            led.blue.show();
        });
    }
    else {
        relay.turnOff(1, function(err) {
            if (err) console.log("Err turning off relay 1", err);
            led.blue.hide();
        });
    }
}