I am very pleased that this project is in selection 20 finalists out of 193 for the challenge IceBox Firstbuild / makerbot . I want to thank those who you vote for me. Winners will now be announced at CES2015 the week of January 5, 2015.

While looking for an idea for my first FirstBuild (https://firstbuild.com/rr/usb-bulb/), the question which always came back to me was “ how to supply my products in my fridge”.

I needed a simple and long-lasting solution. I wanted everyone to develop their own apps and especially not deteriorate the insulation. This solution will allow everyone to change the possibilities of our fridge.

The system must be scalable with a USB port in order to supply a Raspbery, an Arduino…
First of all, it will allow to connect the LEDs to get the light lost by this change.

So I thought : “why not to use the power already existing in our fridge?”
Many of fridges use E14 lamps.
I had an lamp out of service. I decided to start from that basis.

Please find below the required equipment :
– 1 E14 lamp
– 1 Iphone charger
– 2 printed objects
– 2 stainless steel screws M3
– 2 stainless steel nuts M3
– Tools: hammer, tape, plastic bag, soldering iron, resin or glue gun.

I chose to use a Raspbery for the project.

For the electronic part, I have set up the following objects :
– a sensor photoresistor to turn the light on while opening the door, leds are therefore connected to Raspbery
– a temperature sensor DS18B20
– a humidity sensor
– a buzzer

For the programming part, I installed, in my fridge, an apache server, mysql, php (node.js could be good as well) which is a web server that gets the temperature, humidity and anytime soon pictures. To complete, I also set up an email warning if a high temperature occures.

The graph of temperature and humidity allows to follow the evolution on my computer, tablet or Iphone.
As for the buzzer, It rings when the door is left opened too long with the photoresistor.

The project described can be improved by setting up (or options):
a webcam which takes a picture of fridge when light turns on (thanks to the Photoresistor). By the way, pictures could be very useful when we are in a supermarket doing our shopping.
– a voice command
– a barcode reader
– a small lcd
– a switch USB with support
– an ionizer
– An RFID reader : the future products could contain their name, expiry date … so as to order (automatically) from a list created by default. It will alert us when the product passes the expiry date

Video : http://www.youtube.com/watch?v=_FHPkq20k5E

With this solution even the oldest fridges can be connected and I reckon that this project can be the basis for the apps development.

The first thing to do is to tape the lamp glass part to prevent it to burst. For your security, I recommend you to place it in a plastic bag to be able to throw it after handling (see video).

As a result, we have a socket with two wires.
Tin both caps of the charger (warning ! Don’t heat too much)
Take the biggest printed part and put the charger in.
Put the socket and solder the socket’s wires with caps (see video).
Paste (or resin) the socket on the printed piece of the charger and not on the cover. I also recommend to fulfill with a glue gun above and below the soldered joint.

It only remains to bypass the switch or the magnet of your fridge so that the electric current is continuously distributed.
It very is easy to do if you have a switch and shunt the two wire.

For shunt :
95% of the fridges use a switch. I was already thinking about making an adapter to replace switch in fridges.
The switch would be replaced by an adapter already shunted.
But the switchs are not common.

“How to shunt the door switch ?” : Here are the steps :

1 – to unplug the power supply of your device (Very important)

2 – to disassemble your switch. In order to help you, I propose a video that explains how to replace it “www.youtube.com/watch?v=2juGyjXFpyk”

3 – All switches work the same way, so here is the operating principle : two wires enter in the switch, if the two wires do not touch the current, it does not pass, if the two wires touch the current, it passes. To shunt your switch, you must ensure that the two wires are constantly in contact.
If you have like in the video, two wires with female crimp, you can easily buy two insulated male crimps, connect the two male crimps with a wire (you can see this image : http://goo.gl/98x1KF ).
And connect them together with your two wires in your fridge.

You have shunted your switch. You can also weld if you do not use male crimps.

Rest your switch without plugging (it becomes useless).

Now, you have a USB socket in your fridge.

Be careful because handling and modifying high voltage is dangerous.
I suggest that you do this realization with a person with knowledge of electricity.