MP3 Player Hack

The MP3 player and SD mini card arrived a few days ago. I loaded a couple of tracks onto the card and tested it inside the player. It played very loudly and clearly. Choosing a player with integrated speakers was a conscious decision made because i felt that it would create the idea of being 'spoken to' more vivdly. This, of course, will be tested with users.

(official pic)

Once I knew that everything was working correctly I could then start the hack. The first thing to do was open the player up, which was done with a mini screwdriver.

The board was screwed down so it had to be unscrewed and lifted up.

Having a look at the insides i then focused on the on/off switch. There were two settings: on, and on with the light on. The music played immediately with both. The switch was more advanced than i originally thought, but looking at the soldering i knew that one pair of the 10 pins when connected would ovverride the switch. This was a case of trial and error. I used a short jumper cable to methodically move across the pins. I eventually found the 'on' switch and music started playing. I used the indicator light to identify which was correct and i could hear static before i started playing.

The video below shows the mp3 player working with the crossed wires.

What next?

The wires will be soldered down and connected to the arduino via a transistor. This transistor will allow me to open and close the connection via the arduino, and will eventually be able to be done remotely through the teddy bear prototype. This means that a remote user will be able to play sound to another user. 

Why incorporate sound this way?

The expense and versatility. I can connect this system up to the computer using only a couple of pins and it will power itself. The only other option is the Adafruit sound board which uses a lot of pins, and requires a specific type of card formatting. There was also a good chance that it would interfere with the xBee system in many different ways, Using this mp3 player hack means that the price point is down to £10 as opposed to £30-£35 with the adafruit sound board. It also comes with very loud speakers. It plays a micro sd card which makes everything more compact. It requires very little from the arduino; only a on/off control via a single pin.

I will have to look into transistors as i have never used them before and possibly even test them on a motor.

Possible advancements...

Incorporating an mp3 player which can also record sound. This could allow someone to purchase the bear, record it without having to use another devie, and give it to the person as a gift. I also would want to make an accompanying storybook. Anther possibility is using an mp3 player with a screen...