mtg 1: DC circuits html
mtg 2: Handy Cricket
lab 2 html
mtg 3: LogoChip
lab 3 lab 3 html
Lang Ref pdf
PIC 16F876 docs pdf
mtg 4: Project Ideas
assignment 4 html
mtg 5: Bus Projects
lab 5 html
mtg 6: PCB and CAD
lab 6 html
EAGLE home page
EGX-300 Manual pdf
tangible bricks html
project plan html
PCB tutorial html
project report html
Doll Talk pdf
Clay illustration pdf
Navig. Blocks pdf
Cognitive Cubes pdf
Physical Programming pdf
Folk Computing pdf
91.548 Lab 3: LogoChip
due February 13
These are the booting up exercises we did in lab already:
- With the schematic drawing in the Getting Started with the
LogoChip document, wire up the LogoChip on a breadboard, get its
boot flash, then hook it up to the PC, and get bootflash to
run from the software's command center.
- Hook up a beeper, configure its pin to be an output, and write
a loop that makes it beep.
In addition to this, complete one of the following five
activities/experiments. Alternately, using these (or anything else) as
inspiration, design your own cool project using the LogoChip. (If you
choose to do something other than one of the ideas here, please check
it with me first.)
- Design a stepper motor control circuit using the LogoChip. We
have 4-phase unipolar stepper motors in the lab. You may be able to
run them directly from LogoChip digital outputs, but you'll probably
need driver transistors. Write a program to make the stepper motor
go. Implement position control (i.e., commanding the motor to rotate
to a specific position) and velocity control (i.e., cause it to run
freely at a specified number of clicks per second). The velocity
control program should keep track of the absolute position as well.
For reference, see the Predko book, pp. 289292.
- Implement a programmable display using a 5x7 LED array
component. Create a multiplexed row/column scan method so that only 7
LEDs are on at one time. Create a character font so that an arbitrary
symbol from the ASCII character set can be displayed.
- Implement a driver for the DevanTech sonars that are part of
the Botball kit. Have the LogoChip indicate distance to target in a
standard unit of length.
- Create the following experiment in the spirit of Harold "Doc"
Edgerton's seminal strobe light work. Connect a piezo to the
LogoChip, but instead of using it to produce sound, use it as a
microphone. (When it receives a loud noise, it should produce a
signal in the 50 mV range, which is detectable by a LogoChip analog
input.) Use this to implement a clap detector.
Then, after hearing a clap, light a bank of LEDs for a short
interval (10 to 50 milliseconds or so). Now you have a system that
when it hears a clap, it produces a short burst of light a moment
later. (Transistor drivers may be needed to get adequate light from
the LEDs, because they should only be turned on for a very brief
Finally, take the setup to a darkened area along with a regular
latex balloon and a pin. Pop the balloon near the piezo
microphone and in range of the LED illumination. You
should see the open shell of the balloon being popped, before it has
collapsed into shreds!
(This experiment was suggested by Robbie Berg.)
- Build a simple digital-to-analog circuit (DAC), perhaps using four
bits and a resistive network to create a stepped range of output
voltages. Load up some sampled or computed audio data (e.g., a sine
wave) into the LogoChip, and write a program to spit it out at a rate
fast enough to make sound. Listen to the output and look at it on the
scope, and describe your results.
A per previous labs, turn in written documentation of your
activities, including (as appropriate) code listings, schematics, and
discussion of the work.
Monday, 10-Feb-2003 12:00:55 EST