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pyr0ball / pyr0piezo

An AVR/ARM based piezoelectric sensor for use in ultra-precise applications
https://docs.pyroballpcbs.com/
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Wire V_FOLLOW and Comparator for PWM + LPF adjustment #15

Closed pyr0ball closed 5 years ago

pyr0ball commented 5 years ago

This is one part of the solution to https://github.com/pyr0ball/pyr0piezo/issues/1

Experimentation shows PWM DAC is a decent alternative to using the linear resistor ladder for VRef adjustment. Wiring will be fairly straightforward, as shown in the example below: image

Experimentation showed that the topology best suited to the frequency generated by the Arduino's PWM is by using a 10k resistor, and parallel 3.3uF and 10uF ceramic capacitors. 22uF introduced a resonance waveform, and 10uF did not sufficiently smooth out the ripples.

pyr0ball commented 5 years ago

Started on https://github.com/pyr0ball/pyr0piezo/commit/2226025830b979959ceab5072745ae53b767f4f4

pyr0ball commented 5 years ago

Confirmed this method works on breadboard testing. Implemented for Rev.2.x+