Ok here's the problem I have:
I have an unknown coolant temperature sensor that I want to read.
It's resistance changes with the coolant temperature. High resistance at low temperatures, low resistance at high temperatures.
The setup I want is an AT89C2051 reading the sensor's resistance (either thru analog comparator or preferably through other means which will use less pins), then display that temperature on a seven segment display containing 5 characters, 3 for the digits, one for the degree symbol, and one for the unit.
My question is how can I read the output of the sensor, or what parts can I use to make the signal readable by the 2051? I was also wondering if there was a way to read the temp straight from the ECU or would I have to piggyback the sensor's output.
If anyone can point me in the right direction it would be greatly appreciated.
the vehicle is a 1995 Jeep Cherokee Sport 4.0L EFI
As far as the sensor is concerned I havn't been able to find much info about it. It uses a 5VDC input voltage, and the output leads to the ECU. that's about it.
some more info here, this is a chart i dug up of resistances at certain temps:
**broken link removed**