MP3 trigger and LMNC Big Button problem

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ripvanwinkle
Learning to Wiggle
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Joined: Tue Jun 16, 2020 9:39 am

MP3 trigger and LMNC Big Button problem

Post by ripvanwinkle » Tue Jun 16, 2020 10:37 am

Hi,
First of all I'm new to this forum so maybe I've not searched enough but I've tried and I didn't find the right solution for my problem.

So I decided to build LMNC Big Button sequencer and in addition to this I've build Sparkun's mp3 trigger device. The main problem is that mp3 trigger seems to constantly triggering by Arduino even when there is no actual signal coming. Big Button gives stable 0.2v when there is no action, and when I give some sequence I see this on multimeter by various voltage jumping all positive so I'm guessing that the Big Button is OK. I'm guessing that there is a problem with my "inspired LMNC wav trigger" thing.

So, are there any solutions to this problem? I am battling with this thing for days :bang: I AM NOT an advanced builder i'm only beginner both with programming and DIY building so also it can affect but I don't see any bad soldering and error. I really appreciate any advice from you guys.

PS; Recently I've searched that Tsunami trigger works by shorting inputs or via 3.3 positive voltage (I think that mp3 trigger also), but I have no idea what to do with this thing.

KSS
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Re: MP3 trigger and LMNC Big Button problem

Post by KSS » Tue Jun 16, 2020 9:56 pm

Sorry I don't have an answer for you but I DO want to say Welcome to Muffwiggler, ripvanwinkle!
I'm sure someone will be by shortly to answer your question!

Synthiq
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Re: MP3 trigger and LMNC Big Button problem

Post by Synthiq » Wed Jun 17, 2020 3:36 pm

The trigger inputs are active low. If the sequencer has active high outputs, the signals should be inverted. A hardware solution would be to add a npn transistor for each trigger input with emitter to ground collector to trigger input and drive the base from the sequencer via a ~100kohm resistor. It may also be possible to invert the signal in the Arduino code, but be aware that at least trig4 and trig5 can't handle 5V signals and could be damaged if driven from a 5V Arduino but would work fine with a 3.3V Arduino.

ripvanwinkle
Learning to Wiggle
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Joined: Tue Jun 16, 2020 9:39 am

Re: MP3 trigger and LMNC Big Button problem

Post by ripvanwinkle » Tue Jun 30, 2020 3:03 pm

Synthiq, thanks for the advice! For the past few days I kinda abandoned this project but now I'm back. Do you recommended some specific kind of npn transistor? Curently I'm only have some BC547 B 's. They're gonna do the work?

Synthiq
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Re: MP3 trigger and LMNC Big Button problem

Post by Synthiq » Tue Jun 30, 2020 4:33 pm

In this application the transistor type is hardly critical so a BC547B is fine.

ripvanwinkle
Learning to Wiggle
Posts: 3
Joined: Tue Jun 16, 2020 9:39 am

Re: MP3 trigger and LMNC Big Button problem

Post by ripvanwinkle » Wed Jul 01, 2020 3:54 am

Thank you for the answer! I think it’s gonna work.

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