November 17, 2009 by tony We have an interesting situation. We are trying to take over the cruise control of a 1993 Lincoln Town car. This is what we have found: the motor has a socket with 4 terminals labeling the terminals from left to right 1-4 we have that the motor moves in steps depending on the order of terminals energized. I mean that using terminal 1 as the common (+or-) and then closing the circuit on terminal 2 then 3 then 4 with 5 VDC moves the motor in one directions. Reversing the order say 2 then 1 then 3 reverses the rotation. Picture of Motor top view How we think it is working The other socket on the picture is for an electromagnetic actuator that engages the wire to the accelerator. This eliminates the need to reverse the order of the steps since disengaging it returns the accelerator to its original state (just like when you remove your foot). We are unable to find a controller that can control this motor configuration. Also we will need to "hold" the accelerator at a given position for x amount of time by maintaining 5 VDC at the last "step" I hope someone can steer us in the right direction as we have hit a wall right now. Any help would be greatly appreciated. Thanks. Hi Tony, First, I suggest you take a look at Motors and Microcontrollers 101 which talks about how to control an inductive load using a MOSFET, a diode, and a resistor. You will need to apply this strategy to each of the three phases, so you'll need three MOSFETs, etc. One microcontroller pin should go to each. Can you then try just writing a simple program to manually set each pin one by one? Something like: ``````// suppose the three MOSFET gates are connected to PB1, PB2, and PB3. DDRB |= (1<