Install Infrared Remote Control in Amplifier (Home Cinema)

Initially we have a home cinema with 5 speakers and a subwoofer.

The sound is adjusted with potentiometers:

-Volume: 6 X 50K potentiometers

-Sub: 2 X 50K potentiometers

-Rear: 1 X 50K potentiometer

-In this case we can also choose to listen to the sound of one input or another with an interruptor.

The idea starts because the potentiometers were replaced once and now they were already failing again.

On each make and model of speaker you have to look at the potentiometer that is used. These are the digital potentiometers that I found:

• X9C102 = 1kΩ

• X9C103 = 10kΩ

• X9C503 = 50kΩ

• X9C104 = 100kΩ

Step 1: Materials and Tools

At first a prototype was made to verify the correct operation, then the final project was made. I'm just going to describe the final material.

- 9x Digital potenciometers (x9c503p). 0.52€ x 9

- 1x Arduino UNO. 3.07€

- 1x IR receiver arduino. 0.68€

- 1x PCB universal. 0.73€

- Arduino Wires Male-Male and Male-Female. 2.48€

- 1x Led and resistence. 0.0€

- Pins female-male to PCB. 1.81€

- Pins male-male to PCB. 0.54€

- Relay. 0.47€

- Infrared remote control: Anyone who does not use at home or a smartphone with infrared app.

-Tools: Tin, Tin machine, Multimeter.

Step 2: Circuits

The electric circuits are made in fritzing you can download the file friztingconections.zip and open it with this free program:

Dowload Fritzing

With this program they can also do the pcb and send it to you. But I chose to do it myself since it is cheaper.

Step 3: Software (Arduino)

I'm pretty new to arduino, I'm sure the program can be made better but in this way works perfectly.

I put the libraries that I used:

- Digital power meter

- Infrared control

- Memory storage EEPROM: It is on libreries that come original.(This is not necessary to use it but it is used to save the data of volume, rear or sub and if we turn off the arduino and turn it on again it reads the saved data of the Volume, rear or sub)

I also put two additional programs:

-One to read the code that the remote control emits on each button

-Other to delate eeprom memory

I left the pin13 programmed in case I put another relay later.

Step 4: Prototypes

1 - The first circuit was a prototype to verify the connections and the correct volume operation.

I used a small speaker, an aux cable cut and a multimeter to see de resistences values.

2 - The second prototype I replace the small speaker and connect directly to the amplifier.

Y upload a video where you can see how the rear changes.

**NOTE: You have to use good loudspeakers or headphones to listen the video.

Step 5: Doing the PCB and Conecting

I did the pcb board as best I could following the electrical scheme previously made.

In the web frizting also have the possibility to make them and send it home following the escheme done, or do any other PCB.

In the electrical schematics I did not specify how to give arduino a voltage to work. In my case I looked for inside the amplifier a power supply that was between + 6v and + 12v. You can see in same photographs that I connect a red and a black wires. The red I connect it to VIN and the black to GND.
You can connect the arduino in any other way.