This is the first time I use a High impedance piezo sensor and the problems went pretty quickly.
Here is the piezo I used :
- Manufacturer part number : PKGS-00GXP1-R
- Rating : 0.35pC/G (+/- 15%)
- Range is between 0 to 50 G.
I read that we always need to amplify the piezo signal when it's a charged piezo.
So, I'm trying to make an amplifier for this but I can't make any correlation between the G and the voltage I get from this.
Might as well say that I don't even know how to read the output from the piezo signal!
Here is the amplifier schematic:
Here is a scope view of a small shock.
Ch1 yellow : ADC (amplified output signal)
Ch2 blue : BS170 Gate (piezo output signal)
- How to read a piezo signal like the signal on the scope? Should I read only the first Edge from the signal like in the image below?
- What is pC/G ?
- How to make a convertion pC/G to V ?
- Is my Amplifier even correct? Any other low-cost suggestion ?
Lectures about High Impedance sensor:
- When I said low-cost, I mean, the lower the better. If I can make it under 2$ (piezo not included) it would be awesome.
- The sensor is near the MCU. I want to log any shock made to the device. So physically, the piezo is at 5mm of the amp-op input and the amp-op output is direcly linked to the ADC input of the MCU (Will probably add some protection). Everything is on the same PCB.