The MCP6002 is powered by 3v3 and ground. So outside of the 0 to 5V range, the opamp output will clamp between 0 and 3v3. In these cases the negative input off the op amp will not keep to ground. However the resistor values ensure that the opamp input doesnt exceed the supply for large positive inputs. For large negative inputs the internal esd diode of the mcp6002 clamps the voltage to a diode drop below ground.
Similarly in Clouds:
https://pichenettes.github.io/mutable-i ... ds_v30.pdf
The position/density CV circuits seem to not care much about sending negative voltages to the STM32’s ADCs, while these ADCs (as far as I can work out) can only handle positive voltages without damage, only scaling the input by x0.6 and offseting by -3.33V (while also inverting the result).
This works fine for 0 to 5V, but it would be sending 9.3V on the STM32’s ADC with a -10V CV input?!
Statistics: Posted by tmar92 — Thu Jan 09, 2025 6:07 pm