ECE 4760: Homework 4

  1. Describe in detail why there is a diode across the motor in lab 4. Include direction of inductive current flow during each part of the PWM cycle.
  2. Explain why you need hysteresis on the comparator in lab 4.
  3. You bring up TRT with three tasks and it continually resets. List at least 4 reasons why it might be happening.
  4. What MCU hardware is used by TRT? Assume example one on the TRT page.
    Can you use timer0 for your own code? How about timer1 and timer2?
  5. Describe how you are going to break down the exercise into tasks.
  6. Describe the variables which will need to be shared between tasks.
  7. Assuming 1000 rpm for the fan motor, what prescalar setting will you use on timer 2?

August 5, 2014