Meet’s Epic Welcome Music Project

The project I have been working on of late at BlueStamp Engineering is an mp3 player of sorts that starts to play music when you open a door. It’s interesting to work on because it’s not too difficult but it does provide a challenge. I experimented with different sensors and ways to write my code but with the help of Bill Porter ( and sparkfun’s mp3 shield, the coding went a lot smoother.

Credit to for help with finding the materials and the inspiration.

What I wanted the project to do was play music when I opened the door but I also wanted to be able to pause/stop the whole thing whenever I wished to. When you open the door, music will play and you can switch the music by a press of a button. When you close the door, the last song that was playing will play out and then the music stops. I added a switch that stops whatever music is playing and no music will play if the door is opened until the switch is turned back on.

Here are the materials I used:

Final Bill of Materials for Epic Welcome Music project

  • 2 speakers
  • 1 hall effect sensor (or reed switch)
  • A push button
  • Switch
  • 2 LEDs to test
  • breadboard
  • Sparkfun MP3 shield
  • arduino uno
  • A 100k or 10k resistor
  • 2 10k resistors
  • A 3-5 of 1k resistors (for the LEDs); you might not need all of them but keeping a few of these handy will help you out later on
  • Alnico Magnets (most any other magnet will do but if your hall effect sensor doesn’t come with one, you will need this)
An Overview of the Final Wiring on a Protoboard
An Overview of the finished wiring on a protoboard
Actually building it:
The Reed Switch

I started off by soldering the Sparkfun Mp3 shield and placing it onto the Arduino Uno. Once I had that done, I placed a wire leading from the 5v on the arduino to power the reed switch that I used. When the reed switch closes the circuit, power travels through to the other wire which leads to a pull-down resistor and a wire leading to an analog pin for input. Using the analog pin wasn’t necessary but the sparkfun mp3 shield has some pins you can’t use for certain purposes so I just avoided them. So once I attached a 100k resistor leading to ground (the green wire in the image) and a wire to sense the voltage (the orange wire to the left), I was done with the hall effect sensor. To test it and make sure it worked, I coded in my arduino to send voltage through a wire (the yellow one to the right) and light up an LED (the green one) when the reed switch sensed a magnet. The yellow wire leads to a 1k resistor which leads to the LED which is soldered to ground. When working with LEDs, I had to make sure they were in the right direction otherwise they wouldn’t work.

The Switch

The next step was adding the switch. This allows me to turn the music off whenever I please. I used a rocker switch and I soldered wires on to it. I hooked one wire up to power by soldering a connection underneath the protoboard to the yellow wire on the left that also provides power to the reed switch. I originally did this on a breadboard to make sure everything worked first and it helped give me a better idea on how the power should be connected. The other wire on the switch I soldered to a wire leading to an analog pin on the arduino and a 10k resistor leading to ground. I also soldered a wire leading to 1k resistor leading to an LED (the red one in the image) on the other wire of the switch.

The Button

I soldered wires to the button as well and placed one wire leading to ground. The other I had go to a 10k resistor which led to ground and I also soldered a wire on there which lead to another analog pin.

Here is an image of the bottom of the protoboard; it shows a bit more of the connections and how I did them:

Source Code and Schematic that is helpful for my project (ZIP file): EpicWelcomeMusic

To see it in action check out this video:

However, before it was finished, I had to reach some milestones along the way:

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1 Response to "Meet’s Epic Welcome Music Project"

  1. I am also working on this prcoejt through Robert Faludi’s book and I have trouble getting my Bell circuit to work. For the router XBee, when I have a LED in the RSSI pin it doesn’t lit up. It lits up for my Coordinator so I know its receiving information, only my router doesn’t receive it. Any ideas? Also, for the buzzer is it getting a constant pulse modulation or just react to the button being pressed to get a reaction.

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