Asked — Edited

Sparkfun Mp3 Trigger V2

I am having a problem with the MP3 trigger. I have it connected like the video, but it does not want to play with EZ-B. I have connected the external power and speaker, and tested out the MP3 trigger and it works. Red Power light is on and green lights blinks like it should.

When I connect it to the EZ-B and set it up the Red power light comes on but the green light never blinks nor does it play.

I have connected the MP3 to external power and connected only the white wire to the EZ-B. The Green light goes crasy I think it is playing the different MP3 that I have on the sd card, but it is playing only a second then play the next, and the next so forth and so on. This before I even setup ARC for the MP3 Trigger.

to get the MP3 Trigger back to normal I have to remove the white wire from the EZ-B and turn off the power.

I beleive that I am runnung the most updated ARC and Firmware for EZ-B.

The wires are setup white wire to RX, Red wire to USBVVC, Black wire to Ground.

Have I missed a step? or damaged something on the MP3 Trigger?

Thanks for any help you can give me.


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@hillcrest1297 Not sure if I can solve your problem but I have used the MP3 TRIGGER and it works ok on ezb

I presume you changed over the power source switch ( external to usb) If it works ok on external power source,I would disconnect the white wire then you have +5volt & ground to board then it should power up as normal with the green led flashing as per manual,if thats ok .I would connect a servo motor to that output of ezb and ensure it works ok.

It cannot change track with only white wire connected,as it requires the red & black also.

ps check you have no short in soldered connections to mp3 trigger



That was it I did not change the switch to usb to tell you the truth I did not see the switch.

Thank you for your help.


Have fun its a super kit Please do not connect audio output to any device( eg external amplifier) except a small speaker without reading notes on sparkfun site as there are grounding issues with card ,it needs to be isolated


Does anyone know if there'd be a problem connecting the MP3 trigger to a small battery-powered speaker? It's not an amplifier in the traditional sense, but it does amplify sound.

I'm going to try to use this:

The sparkfun tech didn't think there'd be a problem with a direct hook-up, but he wasn't familiar with the grounding issue either.


United Kingdom

While I haven't used the MP3 board, or even looked at it to be honest, I can't see there being a problem using that speaker. Sound level may be an issue, it depends how loud that speaker can be.


@ftlum Please take care when connecting any type of amplifier to output The MP3 trigger Data sheet on Sparkfun site outlines examples of isolators.

I Speak from experience !


Bravia, have you had a problem with a small battery powered speaker like the one I linked to above? Also someone one the sparkfun site mentioned a Radio Shack fix. Do you know what part they're referring to?



Is there any point to using Sparkfun MP3 trigger with the new EZ-B v4? It seems like the EZ-B now provides that function.




Not at all Frank. I first had a MP3 Trigger installed in my B9 and pulled it out when my V4 arrived. It's a lot simpler to put sound files in a folder on your laptop and pick them with ARC then the way needed to play them from the MP3 Trigger.


Sounds like you have only two wires connected. The Mp3 Trigger needs power, gnd and signal.

As dave suggests, I would can the mp3 trigger and use the audio streaming feature of the ez-b v4.