The speeduino does not use all the analog inputs on the Arduino. On the MX5 PNP A8 is extra handy as it is already connected to the clamping protection IC:
I want to add a coolant pressure sensor to log in my car. Have purchased a few of these sensors:
https://www.ebay.com/itm/Pressure-trans ... SwxBdZgiGA
3 wire sensor - so needs a 5V supply and has the following transfer curve:
So a small mod to the PCB to get 5V - a series 2.2k resistor for the signal and ground. I added a new connector at the back, just prefer not to try and stuff new lines into the OEM connectors.
Then in tuner studio "Accessories" -> "Local Auxillary Input Channel Configuration" set the source appropriately:
Then in "Tools" -> "Custom Channel Editor" add details for the sensor:
Then add a datalog variable:
And voila - you now have a sensor input you can log with correct scale and units!!!
Testing the sensor on a fixture: