MP3 Trigger with Mini Maestro 24 channels


I’m a student and I haven’t made electronic before, and for my university project, I have to make a droid (like G2 droids in the Star Tours queue at Disneyland).

I bought a mini maestro 24 channels, I made all the animation for the relays, and servos ( a 5 minutes animation) and the software was very easy to use!

Now I want to use the Sparkfun MP3 Trigger to play the music at the same time as the droid moves. I let a “frame 0” to make a delay between the “start” command and the beggining of the animation and I want the MP3 trigger to play only one track. I don’t know how to script it, I plugged it (Rx to Tx, Tx to Rx) and when the micro controler is under voltage, it plays the music even if I haven’t launched the program.

I’m here to get help with this script, and I have to show the droid in front of a jury in april.

Thanks in advance,


Hello, Pierre.

You can find an example of how to play a specific MP3 from the MP3 trigger using serial commands from a Mini Maestro in this post from Jon. Please note that along with the connection between TX from the Maestro to RX of the MP3 Trigger, you will also need a ground connection between the two boards. Also, you should double check that the MP3 Trigger’s initialization file is set up to make it expect serial signals. You can learn more about this initialization file and the MP3 triggers settings in the MP3 Trigger’s user’s guide. Once you have that set up, you can configure the Maestro’s serial settings to match (e.g. it sends the serial signals with the same baud rate).

By the way, if you are only trying to play one MP3, it might be more practical to trigger it using a digital output from a Maestro channel configured as an output, which can be done with the sequencer. According to the “Using the Trigger Inputs” section of the user’s guide linked above, when the MP3 Trigger is set up for using the trigger inputs, grounding the pin that corresponds to your MP3 filename should play that file. This can be accomplished by sending a digital low output from a Maestro channel to that pin.


Thank you a lot!

I made it and it works!

Is it possible to stop the MP3 when I remove the jumper?

Thanks in advance for your answer.


I am not sure which jumper you are referring to. From your original question it sounded like you were triggering the MP3 using the Maestro, but now it sounds like you might be using a physical jumper to start the MP3. From the description in the user’s guide, it sounds like the MP3 trigger only looks for the jumpers once it finishes playing the selected MP3. However, there is a on-board navigation switch that can be used to start or stop the current MP3 file. When the switch is in the middle position, pushing it in should start or stop the current MP3. If you want to be able to stop the MP3 from the Maestro, you should be able to send the “Navigation - Start/Stop” serial command.


Hello Brandon,

It is the VSRV to VIN jumper in my Mini Maestro 24 Channels I was talking about. Which allows me to play the script when I plug it. :slight_smile:
I wanted to know if it is possible to send a message to the other cards to stop when the jumper is removed. In my case, to stop the music when I remove the jumper.

In my project, I will replace this jumper by a basic switch. When I turn On the switch, it will be like I plug the jumper, and when I turn Off the switch, it will be like I remove that jumper. It’s to start and stop the animation of my droïd. And I hope I can stop the music when I turn off my switch, as the music starts when it’s turned on. :smiley:

I hope it will help you to imagine what I want to do.


From the information in MP3 Trigger user’s guide, it does not sound like there is a good way to stop a track in the way you want to.

One way you might try doing this is to send a signal to play a dummy track that is blank and interrupts the current track. To do this from the Maestro, you would need to set up the switch on a Maestro channel’s signal pin instead of using the VSRV=VIN jumper. Then, you can write a Maestro script that starts the dummy track when the switch is triggered.


Thanks a lot Brandon :smiley:

I’ll try to make this on my droid :slight_smile:

Best regards,