JRK 21v3 & Arduino, How can I set up limited motion?(Solved)

Hello everyone,

My name is Lodi, 20 year old and an Automotive student. I am currently working on making the throttle control on our engine dyno electrically controlled.

I am using the Invenscience i00800 with the jrk 21v3 controller, and the Arduino Uno SMD. The input signal to the Arduino is 0-5VDC, and the board converts this to a PWM signal. This PWM signal goes to the jrk and controls the servo.

This setup is working like it should, right now. To control the throttle I only need a very limited motion of around 30 degrees (or even less), and this is where I am stuck. I would like to control the servo in this limited distance with the full 0-5V signal. So that I can precisely set the position. When I try to set a scale limit (inside the Pololu environment) the servo will only travel the degrees that I want it too, but it reacts the same to the input signal as before and this results in a huge dead zone, using only a small portion of the potentiometer.

As I said, I would like to use the entire range of the potentiometer to control my desired degrees of rotation (<30 degrees).

I hope you guys can help me !



Well then,

I spent quite some time trying to figure it out today.

It worked out for me like this:

The ‘example’ program for servo control of the Arduino Uno scales the value of the potentionmeter down or up to the desired turning degrees. (Normally 0 to 180) , I changed this to 60 - 90 and now I have the limited movement that I was looking for!

I am now able to control this small movement with the full 0-5v signal. (Turns into PWM in the Arduino and sends the signal to the jrk)

This time I solved it myself, but maybe it is usefull for somebody else. :slight_smile:


Hello, Lodi.

I am glad you were able to get it working; thanks for sharing how you solved the problem.