[Social Robotics] [default] problem to rotate the robotic arm
I'm having a trouble with a project I'm doing in college. I'm doing a robotic arm, and the engine that sits at the base has to rotate 90 degrees to right, after that, back to 0 angle and then, rotate 90 degrees to the left, but it makes a move to 360 degrees. What should I do to set the angle of rotation of the base?
I did not find the right solution from the internet.