Smartphone garage door opener
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original in en Guido Socher
AboutTheAuthor:[A small biography about the author]
Guido likes Linux because it is a really good system to
develop your own hardware.
Abstract:[Here you write a little summary]
Nobody leave these days the house without keys and mobile
phone. Wouldn't it be nice if you could use your mobile
phone to open or close the garage door?
No extra garage door opener device. Just use you mobile phone!
The tuxgraphics garage door opener is not limited to just
one type of smartphone. It does not require the installation of an app. It works with any phone that has
a web browser built-in. This garage door opener can be used from an iPhone, from an Android phone or any data capable phone. It does not even have to
be a smartphone.
The title image with the fighter jet in the garage is courtesy of http://style-your-garage.com. The company makes large waterproof posters to decorate the garage door.
ArticleIllustration:[This is the title picture for your
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What it looks like
This garage door opener can control up to 4 doors.
The system is based on the tuxgraphics ethernet board.
On one side you connect it in parallel to the push buttons which are
inside your garage to open/close the doors and on the other
side you connect it to your DSL router to be accessible over
Optionally you can attach a little switch which detects the state
of the door. This way you can see when the doors where opened or
closed and what the doors current state is.
Overview drawing. The blue connections are added.
This works with any motorized garage door opener
hardware as long as that hardware supports wall mounted wired push buttons
inside the garage.
The door contact is optional but very useful. This allows you to see
on the smartphone what the current state of the door
is. The system keeps a list with the history of the last 50
events and one can see in this history at what time the door
was opened/closed no matter if it was via the phone, wall mounted
push button or wireless remote control.
The ethernet board runs a web server. In other words you
have a web interface to your garage door and you can operate
it from your phone or any of your computers:
Controlling the garage doors from different devices
When you access the web page of your garage door opener
then you can not do anything without password.
This garage door opener has many different security features
to make access both secure and convenient.
The system has the following 3 passwords:
- door passcode 1, door passcode 2. Those passcodes can be used
to open/close the door or look at the history log. The idea of
having two passcodes is that you can see in the history log which
passcode was used at what time. You could e.g keep one in the family
and give the other one to somebody else, e.g the lawn service.
These passwords are called passcode but they can be any string, not
- master password: this password can be used to change any
of the other passwords and to enable code free access for specific
devices (more on this below).
The main page.
On the main page you see the door states. The symbol |.| means
door open and the symbol |=| means door closed. The above
system is configured for two doors. You can have up to 4 doors.
Below the door states you select which of the doors to open/close and
then you enter the passcode to activate the door.
When you come by car and you open/close your garage door every day
then it become very quickly annoying to enter a code every time.
The system offers therefore the possibility of passcode free
access. Up to 3 devices (mobile phones or computers
with web browsers) can be configured that way.
It works by storing a fingerprint of the device and setting a cookie
in the devices web browser. The cookie is good for 600 days after
that you have to re-enable it. You can clear all passcode free
access at any time. If you lost e.g your phone then you just
clear passcode free access and the one who found the phone can
not do anything.
Enabling passcode free access for a specific device and the door
control page when passcode free access is on for that specific device (PC in
The system keeps a history for each and every event with
time and date. The time is derived from the system time in
your web browser. This has the advantage that you do not
need to configure the clock.
Here is a screenshot of a history log. The log stores the last
The history log.
"cfree" means code free access. cfree1 is the device number 1 that was configured
for passcode free access. If somebody opened the door by manually
typing the password then you would see "code" and a number.
If you see a door open/close line with
no "cfree" or "code" then the door was opened by some other other
means (e.g push button on the wall).
Run time settings
In the "[set]" menu, accessible from the main page, you
can change passwords. All passwords are store in eeprom.
In other words they will not be lost even if there is
a temporary power outage.
Here is a screenshot of a the password settings page.
password settings page
The system can es well be reset to compile time defaults
in the event that you forgot the passwords (especially the master password).
To do this you will need local access to the ethernet board
and connect pin PD2 with GND. After that power cycle the board
and remove the connection between PD2 and GND. The master password
is now back to compile time default (it should be the string "secret"
unless you changed it). You can now go to the run settings page
and set a new password.
What do I need?
You have seen how to use the garage door opener but what do you need
to build it?
From a hardware point of view you need:
- A tuxgraphics ethernet board. You can assemble one from a kit or you
can use a pre-build SMD board.
- A small 5V or 6V relay for the first door and for every other door
a relay + relay driver parts (a transistor, some resistors, a diode).
- A 5V DC power supply for the ethernet board (old Ericsson or Blackberry mobile phone
charger can e.g be used for this). The power supply should be able to
deliver 5V DC and 300mA or more (depends on the relay).
- A switch to sense the state of the door. This switch is optional
but very much recommended.
From a service point of view you need:
An internet connection
that allows you to run a small web server at home. Most DSL
internet connections allow that. Smaller ISPs will offer
this possibility normally as part of the standard package. Some larger internet
service providers may charge an extra fee or ask you to apply
for a "business account". Those providers use a firewall to
cut incoming connections and they charge an extra fee to bypass the
firewall. If you are not sure if your ISP allows incoming connections
then just give them a call and tell them that you have a
garage door opener which shows up as a web server and if you will
be able to use it.
A static IP address or a subscription to a dynamic dns service such
as dyndns.org or freedns.afraid.org. Initially you can test the
system as well by entering just the the IP address (e.g
http://22.214.171.124 or http://126.96.36.199:80 ).
The ethernet board
The tuxgraphics ethernet board acts as a web server towards the
user and towards your garage door electronics it emulates a
push button. This is done by closing a relay contact for a second
and opening the relay again. The board reads as well continuously
the state of the door sensor switches to know at what moment
the door opened/closed.
The ethernet board is a standard tuxgraphics board. The following circuit
diagram shows just the extra parts you need and how to connect them.
Circuit diagram with external connections: relay and optional connection to
switch to sense the state of the door. The relay contacts are then to be
connected in parallel to the wall mounted push buttons inside your garage. The
best way to connect this is at the motor unit.
Click on the image for a PDF version.
I mounted the ethernet board on a small piece of wood together
with some screw-on terminations for the cables. A simple and good solution
for use in the garage. The system here is made for two doors and
the relays fit onto the dot-matrix field of the board.
Ethernet board and some screw-on terminations for the cables mounted on a piece of wood.
The door contact
To get the state of the garage door in a reliable way is
more complicated than it seems at first. The reason is that
the doors are quite rough mechanical parts and there are
tolerances of up to 1cm (0.4inch) involved. That is: the door will not always
slide or flip back into the exact same position and if it comes
too close to a small door contact then it will just smash it.
The best two options are:
A reed contact and a magnet. This works well for doors that
have mechanics with tolerances of up to 0.5cm, 0.2inch. I recommend
to use strong magnets to allow for a good air gap between reed contact and
magnet (e.g rare earth magnets).
A snap action limit switch and a bicycle spoke or some other elastic wire.
This is the best option as it can compensate for large mechanical
bicycle spoke and snap action switch
The bicycle spoke is a strong enough wire to activate the snap action switch and
it is a bit elastic. It can compensate the tolerances of the doors very well.
The snap action switch mounted on a piece of wood with which it can be attached besides the
The door shown in the below picture is a sliding garage door. It slides up and down.
The bicycle spoke is bent such that it can activate the switch and then screwed to the door.
A similar design can be used with garage doors that tilt back. The switch has just to be
mounted in a different position.
The door contact installed at the garage door.
Wifi to the garage
I did not have ethernet LAN cables in the garage. Therefore I used a WiFi client AP
to connect back to my WiFi DSL router. How this works is described in
When you go for this option then make sure your WiFi router provides a good
signal strength to the garage otherwise this may not work reliably.
You can use a WiFi range extender if the signal in the garage is weak.
The WiFi range extender has to be placed somewhere in the middle between
your WiFi router and the garage.
The final installation in the garage. I made a little shelf below the garage ceiling.
The tuxgraphics ethernet board is under the blue ethernet cable and on the left
is the WiFi Client AP.
2G, 3G, WiFi
The best option is probably to make the smartphone garage door opener available
on the internet. For this you need to configure port forwarding in your DSL router and
you need to either get a static IP address from your internet service provider or
use dyndns.org to make the system accessible at a fixed known name.
After that you should be able to access the web pages of the garage door opener from the web browser in your smartphone.
It does not really matter if your phone a 2G (GSM), 3G (UMTS) or other type of technology.
The pages provided by the garage door opener are very small and therefore bandwidth
is not an issue.
Another option is to not make the system available over the internet and only
use the local WiFi network around your house. If you have a smartphone which
supports WiFi then this is an option. The problem is however that smartphones do
need time to detect a WiFi when arriving from outside. Normally they do not
switch the connection type when there is an ongoing data connection. In other words
you might find yourself fiddling around with the settings in your phone in front
of the garage until you will be able to open it. It's a different story if you
do not have a data plan with your mobile service provider. In that case
the phone might switch a bit faster to WiFi.
Here are some photos of the user interface on a smartphone.
The pages are made such that they zoom automatically
to the right size. No manual zooming/resizing
How fast is it?
Nothing can be faster than a garage door remote control. However
those garage door openers have no built-in security.
This smartphone garage door opener application is quite fast too. The page loads
much faster than standard web pages because it is small. You will spend most
of the time doing some kind of gesture to unlock your phone.
All recent smartphones allow you to save a HTML shortcut on the
home screen. Once you have unlocked the phone, you click on the
shortcut and with passcode free access enabled you are right
on the page to control the doors.
The buttons are
nice and big. This is easy to use from a touch screen.
I use it now every day. I stop the car on the driveway to unlock
the phone, click, click and the door opens.
This smartphone garage door opener has other advantages too and
you can use it in addition to your existing system. You will
usually have the phone in your pocket e.g when you are working in the garden.
This way you can easily open your garage door and get some tools or
whatever you need. You can temporarily give a passcode to a friend while
you are on vacation even when you are already out of town. Just tell him
the code. Later you can disable access again.
If you have the possibility to enter your house via the garage then you
can use it when you went for a walk to the letter box and you
forgot the door keys. It's convenient and opens new possibilities.
The history function is good too. Did my wife already leave to pick-up
the kids or do I have to go there after work? Just check the
history page and it gives you an idea.