I am trying to take control over a trolley using Arduino. The existing control is done into what I assume is a microchip, by means of a potmeter with a switch. I want to control the trolley independently of the pot. This means that I want to leave the pot in place, and connect a radio controlled Arduino in parallell with the pot, and reproduce the potmeter signal.
Since the pot will conduct to ground in its lowest position and to 5v (i checked) in its max position, I was thinking of using diodes from the pot and from the arduino "pot output" to direct the current towards the micro and not to the other parallell "pot". Am I on the right track here?
Also, the "pot output" from the arduino will be pwm, will the other micro understand that as an analogue signal, or should I try with a low-pass filter as described in http://www.thebox.myzen.co.uk/Tutorial/PWM.html?
Awaiting the experts, thanks in advance.