Hi!
Project:
I want to make my car's computer show me the remaining distance, using the level of the pressure in the LPG's tank. I figured out that the LPG pressure sensor is just a potentiometer, so it is the easy part to get the current level from the LPG tank with analogread. It is working between 0-5V.
The other thing is that my car's fuel level sensor is a potmeter too. i was be able to manipulate it slightly with a potentiometer hooked to the ground and +12V. It is dark outside now, so i did not wanted to cut the wire to take better measurements and also the instrument cluster is counting the level by average and not the actual level of liquid inside the tank, so i have to wait a while. It may work between 0-5V. The sensor's other wire is connected to ground. Between the wire and ground was 2.9V and the fuel tank was almost empty.
My question:
How could i give a signal to theinstrument cluster to manipulate the fuel level?
My first thought was a digital potentiometer, but that will arrive to me after 3-4 weeks from ebay, i cant get them locally, or the price would be 2-3 times more than buying from ebay.
The other thing i was thinking of was if i use the arduino's pwm with a transistor and control the resistance with it. Is this a working idea? Is the other microcontroller in the instrument cluster will get the correct voltage i want if it is created with a PWM signal?
Thank you!