ME414/514
Homework 4
Due 4-20-2009
Midterm Review
Background:
This homework assignment will be done individually and will provide some review for
the midterm on the 20th.
Homework Tasks:
1. Graph a voltage vs degree graph for a 300 degree 10K potentiometer. VCC is 4.3
volts.
2. Graph a digital value vs voltage graph for a 8 bit ADC. The formula below is for
10 bits. Vref is VCC. Calculate the resolution of each digital step.
3. Refer to the lab 3 code for this question:
Sketch the TCNT2 value when the OCR2A register is set to 100. The
period of the counter is 8 microseconds. When TCNT2 and OCR2A are
equal an interrupt is executed below.
 How often is this interrupt called?
 How long does it take for MotorPWMValue to cycle from 0 to
255?
 Sketch the output of PORTD2 being applied to motor two enable if
MotorTwoSpeed = 100.