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. Go to the Human Benchmark site and measure your reaction time. What is your average? For an insanely fast reaction time see this video.
  3. Refering to the protoboard design page (and, of course, the Mega644 datasheet), describe the function of each of the components connected to pins 9, 10, 30,31,32 of the MCU.
  4. Estimate the Thevinin equvalent output resistance of an i/o pin from the Mega644 data sheet. Can you drive an LED directly (you may need to look up the I-V curve for a red LED)?
    What is the value of the best current limiting resistor?
  5. Read the Hints on Debugging page.
  6. The following code sets up timer0 to interrupt at a uniform interval.
    Explain in detail what each statement does and why it is necessary.
    What is the interval?
    TIMSK0= (1<<OCIE0A);
    OCR0A = 249;
    TCCR0B= 3;
    TCCR0A= (1<<WGM01) ;
February 13, 2012