In this instructable I will introduce you to the "renovation" of an electric wine cabinet that was no longer functional. This one of my co-workers asked me if I could fix it because it wouldn't start at all.

I first tried to repair the cabinet's original power card but after spending several hours trying to repair it I had to give up because I couldn't find the failure... It must be said that another person before me had tried to repair this card and that it had caused a lot of damage, it is never easy to take back a repair that another person started!

So I looked if I could find a spare part at a correct price but could not find the same card, so I decided to start from scratch and redo the whole electrical and electronic system myself.

Step 1: System Analysis Before Modification

The original system is composed of:

- of the metal case (the cabinet)

- a power supply and temperature management card

- a peltier effect module

- a fan inside the box that blows on the cold side of the peltier module to circulate the cold air inside the cabinet

- two fans outside the box that blows on the hot part of the peltier module

- a box inside the cabinet that allows it to be switched on/off and set the desired temperature

Step 2: System Analysis After Modification

I have kept some elements, I have modified others, and I have
completely replaced some of them. Here is the detail:

What I kept:

- the metal case

- the peltier module

- the fan inside the cabinet (cold side of the peltier)

- fans outside the cabinet (hot face of the peltier)

What I have modified:

- the control box (switch) and temperature adjustment

What I replaced:

- the power supply and temperature management card:

* the power supply part has been replaced by a 12V/10A adapter

* the management part has been replaced by an Arduino UNO, a motor shield for the Arduino, a card containing 2 relays, and a card used to distribute the 12V voltage to the various elements

Step 3: The Choice of the Arduino

This is the first time I have used an Arduino in one of my
projects. When I have to use a microcontroller I always use Microchip PIC because it is on this type of component that I learned programming during my studies.

But then I let myself be tempted by the world of the Arduino and I must admit that it's really nice! The cards are really well thought out and take up much less space than when you make a PCB yourself. But what surprised me the most was the simplicity of the programming, thanks to a large community there are many libraries that greatly simplify the task!

I understand that these cards have met and are still very successful, everything is easier, there is very little technical knowledge to have to make really cool projects.

The other side of the coin is maybe that it's "too simple", it's as if we had a box with input controls and an output result, personally I always prefer to understand all the mechanics of a system's operation. I don't like to have "grey areas". When you make something and it works but you don't know how or why it often causes problems... But that's just my opinion!

I can't deny the fact that the whole Arduino ecosystem, supported by a large community is a good thing! This makes electronics/informatics accessible to the greatest number of people.

Step 4: The List of Components

For this part I will put only the parts I added:

- Adapter 12V/10A

- Arduino UNO

- Motor driver shield L293D

- Relay 5V

- Temperature Sensor DS18B20

- A small prototype card

- DC-IN cable (from a notebook computer)

- Some dupont cables

- Some spacers (from desktop computer)

- A piece of plywood

Step 5: Wiring Diagram

As I said before, this is my first editing with an Arduino. During my research on the internet I saw a lot of schematics we see the Arduino cards and connections in the form of a "drawing". So I looked into what software these schematics could be made with and found one called Fritzing.
http://fritzing.org/home/

So this is my first schema made with this software, I tried to do the best I could, but I struggled a little to make the different connections between the elements, I didn't have to understand all the functionality of the software.... Practice makes perfect... ;)

On the diagram we can see that the motor shield is not exactly the same as I used but since the pins are identical I took this one. Similarly, we see almost no connection from the arduino to the rest of the elements because in reality the motor shield is connected above the Arduino UNO board, that's why I connected everything to the motor shield on the schema. I also replaced the fans with motors on the diagram because in the end that's what they are...

SRO2004-WineCabinet-Diagram.pdf
Download

Step 6: The Program

For the program I used Arduino's IDE, I also used several libraries to facilitate the use of the motor shield and temperature sensor.

So thanks to the creators of the libraries: OneWire.h, DallasTemperature.h, AFMotor.h and Timer.h

The program and comments are written in French because I didn't plan to make an instructable originally for this project, but anyway it's quite easy to understand.

I put below the program in.ino as well as the libraries used:

Step 7: System Operation Diagram

Here is the diagram of how the system works, not the program. It's some sort of mini user manual. I have put the PDF file of the diagram as an attachment.

Diagram.pdf
Download

Step 8: Conclusion

I did this project several months ago and everything has been working very well since then. It is possible that some informations are missing or that there are things that lack precision in this instructable because it was written several months after completing this project. I apologize for that.

In any case it was a nice project to do, I had to start from scratch but for a rather small budget. And it will probably be more reliable than the original system, which didn't last very long before it broke down. I hadn't planned to write an instructable for this project, it may be less clear to understand than my other instructables but if some elements can be used by other people I will already be happy! =)

I don't know if my writing style will be correct because I'm partly using an automatic translator in order to go faster and since I'm not English speaking natively I think some sentences will probably be weird for people writing English perfectly. So thanks to the DeepL translator for his help;)

If you have any questions or comments about this project, please let me know!