EE 476: Homework 1
due At the start of your first lab period.
- 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.
- Reading from the schematics in the hardware
description, determine:
- if the LEDs are lit when a logic high or low is applied to the connector.
- if the switches outputs are logic high or low when pushed.
- List all jumpers which should be installed for the first lab assignment
and describe why you need each one. Assume that the mcu operates at Vcc=5
volts.
- Estimate the Thevinin equvalent output resistance of an i/o pin from the
Mega163 data sheet. There will be two separate estimates corresponding to
whether the output is logic-high or logic-low.
- Assuming that an LED has a turn-on voltage of about 1.5 volts, and draws
about 20 millamps, how many LEDs can you operate from the i/o ports before
exceeding the chip rating.
Jan 2003