Frank, A PID controller should have three gain constants ("P","I", and "D"). You can turn a PID controller into a PD controller by simply setting the integral gain "I" to zero. If you have found example of code for PID controllers that fit your configuration, you should try that. Then the difficult part of the problem becomes determining the values for the proportional "P" and derivative "D" gains. That is where the PIDTune and ToDiscreteTimeModel functions in the Wolfram Language can help. They do require that you have at least a rough approximation of a mathematical model for your system. Alternatively, there are purely experimental techniques for tuning PID gains, but those are outside of the scope of the this community.

I'm assuming you have not designed the controller yet. To design a PD controller you can use the PIDTune function. It needs to be discretized using ToDiscreteTimeModel to get the equations that can be be used to program the Arduino.

Dear Frank Lopez, the answer was given to you in terms of Wolfram Technologies. This forum is only for the discussions of Wolfram Technologies and Initiatives as it says in the guidelines. If you are seeking general scientific or technical information unrelated to Wolfram Technologies please consider asking on other more relevant forums.