Author Topic: Bluetooth controlled pedals?  (Read 1085 times)

junkemail86

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Bluetooth controlled pedals?
« on: October 04, 2017, 06:25:14 AM »
Hey everybody,
stupid question and something I know very little about.  But how close are we to DIY a bluetooth controlled pedal with something like this?  http://www.taydaelectronics.com/pcb/hc-06-bluetooth-transceiver-module.html
Or even without bluetooth, aren't there digitally controlled potentiometers that we can make something cool with?

micromegas

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Re: Bluetooth controlled pedals?
« Reply #1 on: October 04, 2017, 07:25:58 AM »
They are, and some people have done cool stuff with it.
Once you have a digital controlled pot hooking up a bluetooth circuit isn't a big problem, but you'll have to figure out the way to send control messages (maybe using Open Sound Control?)

There are 3 ways I have seen it done:
a) digital potentiometers [PROS: easy to control via a microcontroller and from the application side][CONS: most of them (the cheap ones) are not really suited for signal applications]
b) VCAs (voltage controlled amplifiers) [usually not cheap, sometimes a pain to work with and they usually involve some extra circuitry]
c) variable resistors with optocouplers (or variable pots using 2 optocouplers) [PROS: best suited for audio & signal applications][CONS: not cheap, you need to match the optocouplers or at least characterise their curves because they have great tolerances]


Chase Bliss Audio uses option c) for his pedals afaik and RobA posted some circuit & software on this forum a while ago to create a digitally-controllable potentiometer following a similar principle. Usually what puts people off is the amount of extra circuitry & work it involves.

That said, I have done some experiments and it is not really complicated if you have some software dev background.
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wgc

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Re: Bluetooth controlled pedals?
« Reply #2 on: October 04, 2017, 09:29:05 AM »
wow, crazy that this came up just as I was posting about something similar in mb's din thread.

Great info, micro.  anyone know if people are using bt for input/output signals?  could make for an interesting looper.
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micromegas

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Re: Bluetooth controlled pedals?
« Reply #3 on: October 04, 2017, 09:44:45 AM »
wow, crazy that this came up just as I was posting about something similar in mb's din thread.

Great info, micro.  anyone know if people are using bt for input/output signals?  could make for an interesting looper.

Bluetooth is not too fast for audio routing, good enough for parameter control though.

Bluetooth latency would be noticeable for real-time applications although a looper is not really "real time", right?.
A looper is not real time but playback needs to be in sync, so depending on who controls the looper's playback you would have ~40ms latency, which is too much.
« Last Edit: October 04, 2017, 09:51:32 AM by micromegas »
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wgc

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Re: Bluetooth controlled pedals?
« Reply #4 on: October 04, 2017, 10:22:33 AM »
gotcha, that makes sense.  Any alternatives that might work for this, zigby zigbee, etc?
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