joshnishikawa
Active member
I was happy to find the Piezo MIDI drum example in Teensyduino especially the notes on how to wire up the Piezo. It’s quite different than any of the info I’ve found so far and this slight mod I did works GREAT!
I have a 10k pot hooked up here which works well to adjust sensitivity on the fly for pads that I'm hitting with sticks. There’s a thread about using a Piezo with Teensy 3.6 that mentions putting a 470 Ohm resistor on the Piezo so I did that too. However, I'm using a 3.2 so my first question is…
Could / should I use a different resistor value there for a Teensy that’s 5v tolerant?
Does that even make sense? I mean I know that resistors limit current rather than voltage but after reading a bit about voltage dividers, clamping diodes and shunt regulators, I can’t quite understand what that diode connected to 3.3v is doing. (By the way, the example sketch doesn’t mention that resistor at all.) It’s mentioned in that same thread that hooking 20 Piezos up to a 3.6 might be pushing it. So, my second question is…
Would I be pushing it to hook 10 Piezos up to a 3.2?
Fast and accurate readings are pretty important to me. I also stumbled upon this peak-holder circuit but it’s from a while back and, since it only has 4 Piezos hooked up to it, it looks like I’d need to wire up about 3 of these if I wanted read 10 Piezos that way. That is unless a Teensy 3.2 can handle 10 without this peak-holder thing (please say yes).
I have a 10k pot hooked up here which works well to adjust sensitivity on the fly for pads that I'm hitting with sticks. There’s a thread about using a Piezo with Teensy 3.6 that mentions putting a 470 Ohm resistor on the Piezo so I did that too. However, I'm using a 3.2 so my first question is…
Could / should I use a different resistor value there for a Teensy that’s 5v tolerant?
Does that even make sense? I mean I know that resistors limit current rather than voltage but after reading a bit about voltage dividers, clamping diodes and shunt regulators, I can’t quite understand what that diode connected to 3.3v is doing. (By the way, the example sketch doesn’t mention that resistor at all.) It’s mentioned in that same thread that hooking 20 Piezos up to a 3.6 might be pushing it. So, my second question is…
Would I be pushing it to hook 10 Piezos up to a 3.2?
Fast and accurate readings are pretty important to me. I also stumbled upon this peak-holder circuit but it’s from a while back and, since it only has 4 Piezos hooked up to it, it looks like I’d need to wire up about 3 of these if I wanted read 10 Piezos that way. That is unless a Teensy 3.2 can handle 10 without this peak-holder thing (please say yes).
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