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Adafruit Audio FX trigger from voltage drop?
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Adafruit Audio FX trigger from voltage drop?

by stiebs on Wed Jul 06, 2022 8:02 pm

I've used the Adafruit Audio FX sound board (https://www.adafruit.com/product/2341) in a couple of projects with hard wired triggers. I'm now trying to hook it up with a wireless remote. I've picked up this remote from Ebay (https://www.ebay.com.au/itm/183369822654).

The receiver board is powered by 12V. I was hoping the output would be solid state relays that I could use to close the contact on the Audio FX board triggers, but instead they are voltage outputs. All outputs float at between 100mV - 200mV when not triggered, and trigger to about 11.8V.

What is the best way to hook up this +12V trigger to the Audio FX board?

Thx.

stiebs
 
Posts: 5
Joined: Thu Feb 08, 2018 2:11 am

Re: Adafruit Audio FX trigger from voltage drop?

by dastels on Wed Jul 06, 2022 8:10 pm

You might be able to use the receiver outputs to drive (directly or through a transistor) relays that then connect the triggers to ground. You might be able to do the same thing with an optocoupler. It's be a lot quieter than relats.

Dave

dastels
 
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Re: Adafruit Audio FX trigger from voltage drop?

by stiebs on Wed Jul 06, 2022 9:07 pm

Thanks Dave,

My first thought was to optocoupler, solid state or DIL reed relay, but thought I'd see if anyone had any better ideas.

Although the next bit might be a bit more challenging - hooking up just a multimeter to the outputs, the activated channel is raised to 12V on trigger, but all the rest are raised to 9V !! WTF? I'm hoping maybe when I actually put load on the outputs that won't happen :/

stiebs
 
Posts: 5
Joined: Thu Feb 08, 2018 2:11 am

Re: Adafruit Audio FX trigger from voltage drop?

by dastels on Wed Jul 06, 2022 10:44 pm

so... with no trigger they are close to 0v? And if you press "1" the 1 output goes to 12v and the others go to 9v? That would be weird. And annoying.

Dave

dastels
 
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Re: Adafruit Audio FX trigger from voltage drop?

by stiebs on Thu Jul 07, 2022 4:34 am

My thoughts exactly. Cheap ebay junk!
I've hooked up two of the inputs with an LED and load resistor, and things are little bit better.

When nothing is triggered both outputs float in the 100-200mV range.
When I trigger one channel, it reads 11.2V, and the non-triggered channel reads 1.2V

Given the .. erm .. quality and consistency of this receiver board, I might look at using solid state relays instead of optocouplers.

stiebs
 
Posts: 5
Joined: Thu Feb 08, 2018 2:11 am

Re: Adafruit Audio FX trigger from voltage drop?

by stiebs on Wed Jul 13, 2022 11:42 pm

Update..

I found a CPC1218 optocoupler from digikey with an input voltage of 5-12VDC, and that seems to fit the bill quite nicely.

stiebs
 
Posts: 5
Joined: Thu Feb 08, 2018 2:11 am

Re: Adafruit Audio FX trigger from voltage drop?

by dastels on Thu Jul 14, 2022 9:10 am

Excellent.

Dave

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Please be positive and constructive with your questions and comments.