Asked — Edited
Resolved Resolved by Dave Schulpius!

Sparkfun Mp3 Trigger

Does anyone one know where to grab a trigger off the Sparkfun MP3 trigger board? I am using one to make the GBot speak but my neon does not light reliably. Im pretty sure its working. It does light briefly when an mp3 file starts to play but does not stay on during the file play. Ive tried adjusting the sensitivity of the neon trigger input without success. Im hoping its not working properly due to line noise or poor s/n



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Ok, I'm thinking 'ground loop isolator'... More later after I install and test...


hi gwen

on the mp3 trigger between the jacks is a little swits that you can chift. maybe that helps.


Gwen, I'm sure you know this but most of the Voice files for B9 we have are only one channel and come out of only speaker. Maybe you have your neon trigger attached to the wrong side. I'm not sure what setup your using to trigger your neon. I used the SparkFun MP3 Trigger when I had the V3 EZB in my B9 and I had the Tech22 sound system to trigger my neon. I had the output on the MP3 Trigger going to the input of the sound amp. I had the trigger wire of the Tech22 attached to the voice channel speaker output on the amp and not the MP3 Trigger. So the way my sound system worked was the MP3 trigger stored the sound files and sent one to the sound amp when EZB V3 sent the command, the amp sent the voice file out of one output channel to B9's one voice speaker. I had to have the Tech22 trigger wire attached to the same speaker output on the amp that B9's speaker was attached to.

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Hope this helps. Dave Schulpius


Also Gwen, The old tutorials for the V3 are hard to find so you may not have seen the one to set up the MP3 Trigger with the V3. If not have a look at the vid below. This method works great. I didn't solder the servo cable connector on the bottom of mine, I just simply plugged into the stereo 1/8 headphone output jack and ran it to my sound amp.

Also the switch Nomad mentioned above is the USB or External Power selector. In the Vid DJ shows this switch being the USB position. This is because you've wired it so it gets it's power from the EZB V3 through the USB pin when you solder the cable to the MP3 Trigger. If the unit does not power up if you wire up in the video just flip this switch.

Also, here's the old page that will give you a lot of info on the V3 and how to hook up supported hardware:

Old V3 Hardware


I did know that Dave. I have the Sparkfun board with all the voice files feeding into one channel of my amp and I did connect the neon trigger wire to the same channel positive out that is also connected to the voice speaker. The neon only comes on for a second each time a voice file plays. I actually have the older tech 2000 setup. The trigger on it has always been temperamental. There's a pot on the music interface that I seem to remember set a threshold value for the trigger input but it doesn't seem to change anything when I tweak it. I am going out later to pick up a ground loop isolator and am hoping this will solve the issue otherwise I probably won't be able to have his neon working by Friday :(

I have the background sound playing through the other channel from a $6 mp3 board I picked up on Ebay.

I'm sure there is a ton of line noise in my system. I had to move the mount locations of the mp3 boards to eliminate hum so I have high hopes an isolator will fix it...


Did find that tutorial and set mine up that way. Thanks :)


Good luck. I hope you can get this worked out in time. The Neon is a sweet feature on our big friend. I've never had to use a Ground Loop Isolator and don't really know what it does. I think It's suppose to clean up electrical noise? I know the adjustment knob on the Tech22 is very touchy and takes just slight turn to get it right. Does your version have two adjusting knobs like in the drawing above? I found a combo of adjusting both knows helped me.

Make sure all your volume controls are set up to the proper levels. In ARC in the MP3 Control there is also a setting for volume that can be missed. It's a slider control at the upper right corner of the window. I always had to set this up to 100%

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Please keep us posted.



Mine only has one pot for tweaking... All the volumes are up.

Here's a diagram of the old setup

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The EZ-B v4 has streaming audio built into it - with the EZ-B v4, you do not need an mp3 trigger


Hmmm... I definitely see upgrade coming. But EZB v3 is what I have for this Halloween...


I gotta say Gwen that I love the simplicity of strimming a voice file from my laptop right to the robot's sound system through EZB V4. The response of the flash to the voice cadence on the neon is even a lot better. When you finally do upgrade you'll want to do the sound mod on EZB to bypass it's built in amp and tie into your B9's bigger sound system amp. Here's the thread I started that will help you do this when you get to that upgrade:

Breaking Out The Sound From The V4 Ezb

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I cannibalized my old MP3 Trigger for the headphone jack. You can see the poor nurtured MP3 Trigger board in the background

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