[propionate]

I have attached code that should do what you want. The while loop is obviously unnecessary if you have this in Teleop or Period Tasks. This code will save the elapsed time of the program to a local variable while a button (the Boolean input) is not pressed. When the button is pressed, it will find the difference between the time at the moment the button was pressed and the current time. This is then divided by a constant to give an output your motor can use.

Let me know if you have any questions.