For a long time I've been trying to make a DIY milligram-accurate scale, and milligram-accurate strain load cells are expensive. Does anyone know if the resolution of this is high enough?
Can anyone explain why the BRIDGE_SUPPLY voltage is connected to the voltage regulator output and PWM signal at the same time (through the FSA5157L6 analog switch)?
Piezoelectric or Strain Gauge Based Force Transducers?<p><a href="https://www.hbkworld.com/en/knowledge/resource-center/articles/piezoelectric-or-strain-gauge-based-force-transducers" rel="nofollow">https://www.hbkworld.com/en/knowledge/resource-center/articl...</a><p>Piezo vs. strain gauge
<a href="https://www.kistler.com/US/en/piezo-vs.-strain-gauge/C00000145" rel="nofollow">https://www.kistler.com/US/en/piezo-vs.-strain-gauge/C000001...</a>
The challenge is that while you can make a strain gauge out of just about anything, making them repeatable over temperature, humidity (in the case of hygroscopic materials, like PCB FR4) and repeated flexing is where it gets difficult.<p>For this, while I'm sure it works, if the humidity and/or temperature changes, the same deflection will result in different readings.<p>If you can calibrate it <i>immediately</i> before each use, or you don't care about absolute values, this is a completely valid option.<p>"Real" strain gauges generally use a constantan resistive element to deal with the temperature variability, deposited on a plastic carrier film (typically polyimide). The film elements then get glued to the stress sensing member. They're fairly inexpensive too.