Arduino sending sound files via bluetooth (First post!)

Projects General Guidance
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Hi everyone!

I’m an absolute beginner in electronics, basically started with zero knowledge or experience and I’ve had an idea for a project and want to know if it is feasible before I learn more about the specific aspects of the project (it’s a long term project!).

Basically I have Hornby DC Hogwarts express train and I want to add sounds to the set. This can be done by a very expensive conversion which is unfeasible, so I’m wanting to add sound to the train on my own.

The set controlled by this analogue controller:

It uses a 19V input, and then a potentiometer(?) which is the nob control, to change the output to the track from 0-12V.

My idea is to link addition cables from the potentiometer into and Arduino Uno. The Arduino would then have an SD card (with WAV files of the train running, the whistle, wheels braking etc) and a Bluetooth transmitter capable of sending the sound files to a receiver. I would then have a Bluetooth receiver, battery and speaker which would need to be very compact that I will put in the train, probably in the tender.

Does this sound like a feasible idea? Would the Arduino be able to use the potentiometer to either speed up the train running file, or if not, vary the volume? This way the train sound will get louder and possibly faster as the train speeds. And then when the potentiometer is turned the other way, have it slow down/get quitter and also play the wheels braking sounds. Then possibly add a button to the arduino to play the whistle?

And ideas/suggestions/advice on the project would be greatly appreciated!

Thanks
MZG

Arduino project.pdf (34 KB)

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a Bluetooth transmitter capable of sending the sound files to a receiver.

I think you mean stream sounds to the receiver not send a sound file, those are two different things.
You can get bluetooth transmitters that can do this but they are not the normal cheap ones. Something like this looks sutiable SparkFun Audio Bluetooth Breakout - RN-52 - WRL-12849 - SparkFun Electronics

My idea is to link addition cables from the potentiometer into and Arduino Uno.

No, because you have no idea what circuitry is on the pot in your controller. It might just be a variable voltage but again it might be in a control circuit to generate PWM for the train's motor. Unless you find out what signals are on that knob, and design an interface to suite, you could damage your Arduino.

You need an oscilloscope to see what signals are on this pot, and the skills to understand what you see. You could search online to see if the schematic has been posted or hacked.

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mzg1991:
Does this sound like a feasible idea?

You could do that but I believe you will be better off having all the gear in the train and control it via bluetooth, i.e. have the sound stored where you want to play it, rather than transmitting it from somewhere else. God only knows how you would speed up the sound commensurate with the train, but that problem would be the same irrespective of where the sound is stored.

There is a swag of Arduino train freaks around this forum and you should get plenty of support.