VDO 320-059

Hello everyone.

I am trying to create a simple device which will monitor water temperature, oil temperature and oil pressure in my car. I already have in my hands the arduino diecimila board, an LCD and 3 sensors. I have connected the LCD to arduino and I can display data on it without any problems.

Now, I am trying to connect one temperature sensor to arduino. The temperature sensor I have is the VDO 320-059 (http://www.egauges.com/vdo_indS.asp?Sender=300F_150C&PN=323-059) I have tried connecting the sensor using one wire which goes from ground to the sensor and one wire which goes from the sensor to analog in 5. I tried to heat the sensor but I always get 0 from analogRead(). What do I need to connect the sensor to arduino?

Keep in mind that I have no idea on electronics! ::)

Anyone has any idea what I should try?

I still haven't found out how to properly wire the temperature sensor to Arduino. Can anybody help me?

The sender usually gives you a resistance to ground..

Try adding a pullup resistor from the sensor to +5v What size resistor? It depends on what the resistance range is of the sender and how much voltage drop it will have at the top of its scale. You may need a resistor double the max value of the sensor (Say at 300F)..

The other way might be to put a large (Say 3300uf) capacitor from the sensor to ground. Pull the pin high to charge the capacitor then switch the pin to an input and monitor when the pin switches from a 1 to a zero. The higher the resistance, the slower the cap discharges. You can correlate that to temperature by figuring the R/C network formula out or just heat the sensor to one value, read it, then cool it to another value and read it, then create a slope formula to compare the results by.

Thank you very much for your answer! :) Unfortunately I didn't understand much :-[

resistance range

The resistance range is 10-180Ohms. What pullup resistor should I use?

About the wiring... I know that ground is on the engine (but for testing purposes I will connect it to Arduino's ground). How many wires I need? One going to pullup resistor which goes to +5V and one that goes to an ADC pin?