Keeping Arm height equal while having preset arm positions & PID loop

VEX V5 General Discussion Technical Discussion
1

Hi,

I’m trying to program our robot’s arm to move together in EasyC v4 using a potentiometer while having preset positions. How would I go about doing this if both potentiometers are occupied by the preset arm position program?

Here’s an example for keeping the arms together:


Left_pot = get analog 1
Right_Pot = get analog 2

If left_pot > right_pot: left_lift_motor = 63
If right_pot > left_pot: right_lift_motor = 63

And here’s an example for preset arm positions


left_pot = get analog 1
If btn1: setpoint = 100
If btn2: setpoint = 200
If btn3: setpoint = 300

if setpoint > left_pot: lift_motor = -100
if setpoint < left_pot: lift_motor = 100

As you can see, each sample will occupy a potentiometer.

Also, is there any advantage to having a PID control loop for drive trains during operator control? It doesn’t seem like a human would need a PID control loop assisting them during the operator control.

2

It doesn’t seem hard to combine the two functions.
If both arms move to the same set point, then they will be moving together, right?

3

They will be moving together but might not move in sync.

Let me rephrase:

Right Arm might be 10 degrees more than Left Arm
If both arms move to same position, right arm will always be (left arm + 10 degrees) until it reaches the setpoint.

4

how about just use one pot for both arms?