Arduino Garage Controller


Introduction: Arduino Garage Controller

This is my first Instructable, so be easy on me! :-)

Although there are many garage door projects on Instructables using Arduinos, I needed/wanted something different. Last year, we had a warm summer and when I would come home after work, I would leave the garage door open about 1 foot so it could cool off. The trouble was that several nights I left the garage door open overnight :-(  So I thought, I could use an Arduino with a real-time clock (RTC) to automatically close the garage door at 9 pm. So I built the first version of a garage controller. I used two sensors, one for "door is closed" and the other for "door is fully open" and a relay. The controller worked quite well for the rest of the summer.

When winter came, I decided to unplug the garage controller since I would leave the garage door partially open. This year when it started getting warm again, I plugged in the garage controller again. The trouble was that the RTC was not very accurate and the time was off. The only way to correct the time was to plug my laptop via USB to the garage controller, a pain because I had installed the garage controller on top of the garage door opener. So I had to climb a ladder with my laptop, connect the USB port to the Arduino, upload a "new" sketch that had to correct time and then upload the regular sketch (that didn't set the RTC).

In the meantime, I had bought a factory refurbished Vera2 "Smart Home Controller" from Mi Casa Verde on eBay. I had also found a Z-Wave home thermostat at Fry's for $14 so I could automatically set schedules for the heating and air conditioning. The Vera also allows me to remotely control the thermostat from my cell phone using one of the many apps that talk to the Vera.

Given that I had the Vera (that keeps accurate time) and the fact that you can write your own "plugins" for the Vera, I thought, I should connect my garage controller to the Vera. Once I connected my garage controller, I thought, Hey, I have an Arduino in the garage, what else can I control? So I decided to add more relays to control my irrigation system and replace the timer I have in the garage. Have you ever tried to manually turn on one zone with today's timers? Now, with my cell phone, I just tap a button!

The garage controller connects to the Vera2 via Ethernet. I'm using an Ethernet shield because they are less expensive than WiFi shields.

I could have used a Raspberry Pi but since its GPIO are 3.3V I decided to stick with the Arduino.

Step 1: Parts & Tools

So here's are the parts I used:
  • Arduino Uno
  • An Ethernet Shield (any shield that works with your Arduino)
  • A 4 Channel 5 volt relay module
  • A PC board
  • A fuse holder for the 24V used by the irrigation valves
  • A polarized connector for the 24V
  • A DB9 male connector with flat ribbon cable (I had laying around)
  • Miscellaneous screws and bolts
  • A plastic box to hold the controller.
  • Various straight and right angle headers
  • Wire-wrap wire (I had laying around)
  • Magnet wire (for the 24V)
  • 2 Switches with NO and NC connections
  • Speaker or telephone wire to connect sensors
  • 2 conductor connectors
In addition, you'll need the following tools:
  • Soldering Iron
  • Solder
  • Drill and bits
  • Files
  • Labeler (optional)
  • Arduino Development Software
  • A text editor
You also must be familiar with the Vera and how to add your own device to the Vera.

Step 2: Schematic/Block Diagram

Here's the schematic/block diagram.

Step 3: Arduino Uno, Ethernet Shield & 4 Channel Relay Module

By trial & error, I first mounted the Arduino Uno to the bottom half of the plastic box by drilling on the bottom. I had to cut  and file away the plastic to allow for the USB connector. I used spacers to hold the Arduino Uno to the bottom. In a similar fashion, I attached the 4 channel relay module to the bottom half of the plastic box.

I also drill/cut/filed the holes in the top half of the plastic box for the Ethernet connector, the 24V connector, the DB9 connector and for the sensors and switch headers.

In the first photo below, I've already attached the wires from the DB9 connector.

Step 4: Breadboard

The breadboard is what connects the Arduino/Ethernet Shield to the relay module and the "outside" world.

Step 5: Door Sensors and Pushbutton

I mounted the 2 switches at each end of the garage door rail. Since I wanted to sense the "normal state" (i.e. the garage door is closed) as HIGH on the Arduino, the closed door sensor is connected to the NO pin and the fully open sensor is connected to the NC pin on the switches.

To open and close the garage door, I then spliced a wire from a relay in the garage controller to the wire coming from the pushbutton on the wall.

Step 6: The Arduino Code

Here's the code running on the Arduino:

Garage Controller
Written by Aram Perez
Licensed under GPLv2, available at

//#define LOG_SERIAL

#include <SPI.h>
#include <Ethernet.h>
#include <Wire.h>

#include <PinChangeInt.h>

#define IOPORT 23  //Normal telnet port
#define NBR_OF_RELAYS 4

// Garage door sensors & pushbutton
#define GARAGE_CLOSED_SENSOR 2 //Connect to NC terminal, active high
#define GARAGE_PARTIALLY_OPEN_SENSOR 3   //Connect to NO terminal, active high

#define RELAY0 4
#define GARAGE_RELAY RELAY0  //Relay for garage door button
#define RELAY1 5
#define RELAY2 6
#define RELAY3 7

#define CR ((char)13)
#define LF ((char)10)

// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network.
// gateway and subnet are optional:
static byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
static IPAddress ip(192, 168, 1, 170);
static IPAddress gateway(192, 168, 1, 1);
static IPAddress subnet(255, 255, 255, 0);

static EthernetServer server(IOPORT);
static EthernetClient client;

static char relayState[NBR_OF_RELAYS];

class GarageDoor
  bool closedState, partiallyOpenState;
  void Init();
  void SetClosedState(bool st){
    closedState = st;
  void SetPartiallyOpenState(bool st){
    partiallyOpenState = st;
  char State() const;
  void PushButton();

static GarageDoor garageDoor;

//This should be a private function in the GarageDoor class
//i.e. GarageDoor::StateChangedISR(void),
//but the compiler gives an error if it is :-(
static void StateChangedISR(void)
  if( PCintPort::arduinoPin == GARAGE_CLOSED_SENSOR ){
    //Must have been the GARAGE_PARTIALLY_OPEN_SENSOR:


void GarageDoor::Init()
  PCintPort::attachInterrupt(GARAGE_CLOSED_SENSOR, &StateChangedISR, CHANGE);
  PCintPort::attachInterrupt(GARAGE_PARTIALLY_OPEN_SENSOR, &StateChangedISR, CHANGE);
  closedState = digitalRead(GARAGE_CLOSED_SENSOR);
  partiallyOpenState = digitalRead(GARAGE_PARTIALLY_OPEN_SENSOR);

void GarageDoor::PushButton()
  digitalWrite(GARAGE_RELAY, LOW);
  delay(400);  //Delay .4 secs
  digitalWrite(GARAGE_RELAY, HIGH);

char GarageDoor::State() const
  if( closedState ) return 'c';
  return partiallyOpenState ? 'p' : 'o';

void setup() {
  // initialize the ethernet device
  Ethernet.begin(mac, ip, gateway, subnet);
  // start listening for clients
  for( int i = 0; i < NBR_OF_RELAYS; i++ ){
    pinMode(RELAY0+i, OUTPUT);  //Zone 1
    digitalWrite(RELAY0+i, HIGH); //Relays use inverted logic, HIGH = Off
    relayState[i] = '0';  //Use normal logic
  if( client.connected() ){

char ReadNext()
  char ch =;
  return ch;

//  g? - return current garage door state
//          c - door is closed
//          o - door is fully open
//          p - door is partially open
//  gb - "push" garage door button
//  rx? - return relay x state
//  rxy - set relay x to y (0 or 1)
void loop() {
  static char lastGarageDoorState = 'c';
  char ch, rAsc;
  if( !client.connected() ){
    // If client is not connected, wait for a new client:
    client = server.available();
  if( client.available() > 0 ){
    int rNdx;
    bool err = false;
    while( client.available() > 0 ){
      switch ( ReadNext() ) {
      case 'g':
        switch ( ReadNext() ) {
        case '?':
          ch = garageDoor.State();
        case 'b':
          err = true;
      case 'r':
        ch = ReadNext();
        switch( ch ){
        case '1':
        case '2':
        case '3':
          rAsc = ch;
          rNdx = ch - '1';
          ch = ReadNext();
          switch( ch ){
          case '?':
            ch = relayState[rNdx];
          case '0':
            digitalWrite(RELAY1 + rNdx, HIGH);  //Inverted logic
            relayState[rNdx] = ch;
          case '1':
            digitalWrite(RELAY1 + rNdx, LOW);  //Inverted logic
            relayState[rNdx] = ch;
            err = true;
          if( !err ){
          err = true;
      case CR:
      case LF:
        break;    //Ignore CR & LF
        err = true;
    if( err ){
      Serial.println(">Say what?");
  ch = garageDoor.State();
  if( ch != lastGarageDoorState ){
    lastGarageDoorState = ch;

Step 7: The Vera Code

To use my Garage Controller with my Vera2, I had to write a "plugin". But adding your own plugin for the Vera is not easy. First, the little documentation that exists on their Wiki is either out of date or incomplete. There is also a forum where you can see what other people have done and ask questions.

Vera uses a combination of UPnP and LUA called Luup. You need at least two files, a "definition" file and an "implementation" file. The trouble is that the implementation file is a combination of XML and LUA. The only way to test your LUA code (at least that I'm aware of for the Mac), is to load the implementation file and hope it runs. Loading your files and restarting the Luup engine takes a minute or more, so the process is slow. There is no debugger and your only debugging tool is the logging facility. You view the log, you can either SSH into the Vera or use the following URL: <yourVeraIp>/cgi-bin/cmh/". If there are easier ways, I have not found them yet.

Unless your device is a "well known" UPnP type, all the cell phone remote control apps will not be able to control your device. Since I want to do remote control, my Garage Controller appears as a "Garage Controller" that has the following child devices:
  1. A Dimmable Light for controlling the garage door (remember, I want to partially open the door)
  2. Three Light Switches for each of the relays that control my irrigation zones.
So here is the Definition File (save as "D_GarageController1.xml"):

<?xml version="1.0"?>
<root xmlns="urn:schemas-upnp-org:device-1-0">
    <friendlyName>Garage Controller</friendlyName>

And here is the Implementation File (save as "I_GarageController1.xml"):

<?xml version="1.0"?>
    local GC = "Garage Controller, device: "
    local GC_SID = "urn:schemas-aram-perez-com:device:GarageController:1"
    local SP_SID = "urn:upnp-org:serviceId:SwitchPower1"
    local DIM_SID = "urn:upnp-org:serviceId:Dimming1"
    local CR = string.char(13)
    local FIXED_LEVEL = "30"
    local CSI = string.char(27, 91) --ESC+[
    local parentDevice
    local garageDoorStatus

    -- -------------------------------------------------------------------------
    -- Log with color

    function Log(device, msg)
        luup.log(CSI .. "35m" .. GC .. tostring(device) .. ", " .. msg .. CSI .. "0m")

    function LogL1(device, msg)
        luup.log(CSI .. "35m" .. GC .. tostring(device) .. ", " .. msg .. CSI .. "0m", 1)

    function LogL2(device, msg)
        luup.log(CSI .. "35m" .. GC .. tostring(device) .. ", " .. msg .. CSI .. "0m", 2)

   function startup(lul_device)
        local device = luup.devices[lul_device]
        local ipAddress, ignore, ipPort = string.match(device.ip, "^([%w%.%-]+)(:?(%d-))$")
        if (ipAddress ~= "") then
            parentDevice = lul_device
            if (ipPort == nil) or (ipPort == "") then
                if (device.port == nil) or (device.port == "") then
                    ipPort = 23;
            Log(lul_device, ("starting up, connecting to " .. ipAddress .. ", port " .. ipPort))
  , ipAddress, ipPort)
            child_devices = luup.chdev.start(lul_device);
           luup.chdev.append(lul_device,child_devices,"GD", "Garage Door", "urn:schemas-upnp-org:device:DimmableLight:1", "D_DimmableLight1.xml", "", "", true)
           luup.chdev.append(lul_device,child_devices,"Z1", "Irrigation Zone 1", "urn:schemas-upnp-org:device:BinaryLight:1", "D_BinaryLight1.xml", "", "", true)
           luup.chdev.append(lul_device,child_devices,"Z2", "Irrigation Zone 2", "urn:schemas-upnp-org:device:BinaryLight:1", "D_BinaryLight1.xml", "", "", true)
           luup.chdev.append(lul_device,child_devices,"Z3", "Irrigation Zone 3", "urn:schemas-upnp-org:device:BinaryLight:1", "D_BinaryLight1.xml", "", "", true)
            local value = luup.variable_get(GC_SID, "DelayPartialOpen", lul_device + 1)
            if (value == nil) or (value == "") then
                luup.variable_set(GC_SID, "DelayPartial Open", "3", lul_device + 1)
            -- Assume all irrigation relays are off
            luup.variable_set(GC_SID, "Status", "0", lul_device + 2)
            luup.variable_set(GC_SID, "Status", "0", lul_device + 3)
            luup.variable_set(GC_SID, "Status", "0", lul_device + 4)
            local err = "ERROR: No IP address found"
            LogL2(lul_device, err)
            return false, err, "Garage Controller"
        return true, "Ok", "Garage Controller"

    function partialOpen(data)"gb")


      Log(lul_device, ("received data: " .. tostring(lul_data)))
      local ch = lul_data:sub(1,1)
      if ch == 'g' then
          local status
          ch = lul_data:sub(2,2)
          if ch == 'o' then
              garageDoorStatus = ch
              status = "100"
              luup.variable_set(SP_SID, "Status", "1", lul_device + 1)
          elseif ch == 'c' then
              garageDoorStatus = ch
              status = "0"
              luup.variable_set(SP_SID, "Status", "0", lul_device + 1)
          elseif ch == 'p' then
              garageDoorStatus = ch
              status = FIXED_LEVEL
              luup.variable_set(SP_SID, "Status", "1", lul_device + 1)
              Log(lul_device, "unknown received data")
              do return end
          luup.variable_set(DIM_SID, "LoadLevelStatus", status, lul_device + 1)
      elseif ch == 'r' then
          ch = lul_data:sub(2,2)
          if (ch &gt; '0') and (ch &lt; '4') then
              luup.variable_set(SP_SID, "Status",lul_data:sub(3,3),lul_device + ch + 1)
              LogL1(lul_device, ("invalid zone number: " .. tostring(device)))
        LogL2(lul_device, "unknown data")

        local garageLevel = lul_settings.newLoadlevelTarget
        luup.variable_set(DIM_SID, "LoadLevelTarget", garageLevel, lul_device)
        Log(lul_device, ("setting door level to " .. garageLevel))
        local status = luup.variable_get(SP_SID, "Status", lul_device)
        if garageLevel == status then
            return true
        if"gb") == false then
            LogL1(lul_device, ("error sending command"))
            return false
        if (garageLevel ~= "0") and (garageLevel ~= "100") then
            local delay = luup.variable_get(GC_SID, "DelayPartialOpen", lul_device)
            luup.call_delay("partialOpen", delay, garageLevel)
        return true

        local relay = lul_device - parentDevice
        if (relay &lt; 1) or (relay &gt; 4) then
            LogL1(lul_device, ("not a valid relay number: " .. relay))
            return false
        relay = relay - 1
        local newTarget = tostring(lul_settings.newTargetValue)
        local command = ""
        local status = luup.variable_get(SP_SID, "Status", lul_device)
        if status == nil then
            status = "?"
        if relay == 0 then
            if status ~= newTarget then
                command = "gb"
            command = "r" .. relay .. newTarget
        Log(lul_device, ("sending: " .. command))
        luup.variable_set(SP_SID, "Target", newTarget, lul_device)
        if command == "" then
            return true
        if == false then
            LogL1(lul_device, "error sending command")
            return false
        return true


On the Vera UI5 (I have tested this with earlier UIs), click the APPS tab, then click the "Develop Apps" sub-tab and then on "Luup files" on the left. You will see a list of current and a place to select files to upload. Once you upload the two files, you click on "Create device" on the left and fill in the information. Under "Description" I enter "zGarage Controller" so that it appears as the last device on the UI5 interface. Once the device is created, I recommend that you "Reload" so that all the child devices correctly display.

You can add schedules to open/close your garage door and your irrigation zones. You can download Vera mobile apps to your cell phone and control the garage door and irrigation zones from anywhere in the world!

Step 8: Future Enhancements and Conclusion

I have some future enhancement that I'll start working on soon:
  1. Add an ultrasonic sensor and LED so that when I drive into the garage, the LED turns on when I've reached the correct spot in garage.
  2. Actually correlate the "dim level" with how open the garage door is (right now it's hard coded to 20%).
  3. Maybe I'll print a better enclosure with a 3D printer.
This have been a fun project for me. I hope you like it and I welcome you comments.

Aram Perez



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    8 Discussions


    This instructable is very nice project. It's amazing to support uPnP.

    I would like to introduce your instructable on WIZnet museum. ( I'm an engineer worked at WIZnet provides W5x00 to Arduino for Ethernet shield.

    Your project is a good reference on everyone. Can I introduce your on our site?

    Thank in advance.

    2 replies

    Hi Midnightcow,

    Glad you liked the project, the Wiznet chips are pretty cool. I've taken a look at the website and it has some very good projects.



    Hi, armaperz!

    Thank for sharing your project for other people.

    If you are interested in other wiznet solutions such as WizFi250, W7500, and WIZwiki-W7500(, I will send them for you freely.

    Thank you.

    Hi Supak11,

    Thanks for information. While an interesting product, IMO, it's misleading to say it's only $30 since you also need a cell phone and WiFi access point. My Garage Controller requires a Vera home automation gateway. The advantage is that with one app I can control everything that's connected to the Vera. With the iHued, their app only controls the garage door.

    Best of luck,

    Very nice Aram! Looks like this is a very useful project. Thanks for the clear details.

    1 reply

    Glad you liked it (and don't forget to vote ;-). As I said, there still some improvements I'd like to make and I'll provide updates as I finish and test them. Thanks!