Martin ROGER / VXDash - History

Updated schematics and PCB layout for release board

Update main.cpp

Clamping free floating outputs to GND via DigitalWrite to avoid ADC noise.

Trip and Odo

Added trip and odometer readings to the pulse counters
Some issues with the MUX on the bench
Added force-reset of the screen
Need to clean up the schematics

Updated LTSpice OpAmp circuit simulation

Went and plonked a non-ideal LM358 OpAmp model. Suspicion is that the Common mode voltage is too close so it is non-linear above 80Ohm (which corroborates the observations from before.
Suggestions of correction :
- Change OPAMP with tighter common mode voltage limit
- Change supply voltage of OPAMP to 7V and above -> Risky business
- Change Rset and Vref to something lower. Ideally could go down to Vref at 3V and would lose a little bit of resolution between 3V and V3 but could also lose the voltage divider (5.1K and 2.7K) thus reducing stray current .

In any case upload a V2 of the circuit with those different options

Create Calibration reference.xlsx

Documenting the excessive current through the Rsense...