ECE 4760: Homework 1

  1. Read all of Lab 1. You should come to lab with a good first draft of the code assignment, but the code is not part of this homework.
  2. There is a 5-step procedure for measuring the capacitance given in lab 1. Estimate the time required in step 2 to discharge the capacitor 99%..
  3. Estimate the value of R2 required to make the time of charging of the capacitor greater than 100 timer counts and less than 10,000.
    You should assume timer1 and set the prescalar of timer1 to full speed.
  4. Estimate the Thevinin equvalent output resistance of an i/o pin from the Mega1284 data sheet.
    There will be two separate estimates corresponding to whether the output is logic-high or logic-low.
    Why is this resistance important in the lab 1 exercise?
  5. Explain how you are going to use interrupt-driven timing to get the capacitance, while updating the LCD every 100 mSec.
  6. Read the Hints on Debugging page.