David Cook thinking about robots David Cook
a robot
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Note: To speed up the home page, the projects and events on this page have been moved from the main home page.

Projects (continued):
Second-generation tach with quad capability Second-Generation Combination Tachometer
To display RPMs on 4-inch tall LEDs, the original digital tachometer circuit needed to be redesigned. A comparator was successfully included along with a canned oscillator, quad-tach mode, and adjustable overheat temperature setting.

The center of the circle is where the lines cross Finding the Center of a Circle
There's a simple method for finding the center of a square, circle, or octagon. The technique is useful if you're making your own wheels. Two lines drawn at a 45-degree angle to two different sides will cross in the center. Perhaps the described tool and pictures will make it clearer.

A homemade double-sided printed circuit board Homemade Double-Sided Printed Circuit Board
After learning how to make a single-sided board, creating a double-sided PCB takes nothing more than a little careful alignment and some through-hole soldering. The example board is two-sided copper with components and DIP sockets on one side.

A homemade printed circuit board with surface-mount components Homemade Surface-Mount Component Printed Circuit Board
Surface-mount components are now the mainstay of the electronics industry. The ability to create a board for these packages is important to anyone wishing to access the latest and greatest technologies.

Three varieties of LEGO crown gears LEGO MindStorms Crown Gears
There are at least three variations of the LEGO 24-tooth crown gears. Watch out that you don't accidentally mismatch pairs!

N-size rechargeable battery N-Size Rechargeable Battery
Information about an N-size nickel-metal hydride (NiMH) rechargeable battery. The small size and ability to be recharged makes this cell perfect for a very small robot.

Parallax Boe-Bot Robot thumbnail Parallax Boe-Bot Robot
A review of a well-engineered commercial robot kit for hobbyists and students.

LEGO MindStorms Chipmunk Chaser Robot thumbnail LEGO MindStorms Chipmunk Chaser Robot
Snapshots and some design notes of a robot built with LEGO MindStorms bricks.

Infrared Transmitter Project thumbnail Infrared Transmitter Project
The heart of this project is a NAND gate turned into a 40-kHz oscillator. A simple 9-volt to 5-volt regulator circuit schematic is also included.

AMP hexadecimal (16-position) rotary DIP switch, #54792-1 AMP Hexadecimal Switch
Details and a sample schematic for a rotary switch with 16 positions that encodes its output as 4 SPDT switches.

32.768 kHz Crystal PLL Clock Generation
The 68HC08 family of microcontrollers has a built-in phase-locked loop that can generate various bus clock speeds from an inexpensive 32.768 kHz crystal. This project shows you how to build the oscillator and connect it to an MC68HC908GP32. Includes schematics and source code.

Bugs with P&E Microcomputer Systems assembler Bugs With P&E Microcomputer Systems ICS08GP Assembler
I've encountered a few bugs with the free assembler for the 68HC08GP20 and 68HC08GP32 microcontrollers. Here are the emails and source code I sent to the developers and the workarounds I'm using.

Twofold 68HC908 Robot thumbnail Twofold I - 68HC908GP32 Robot
A peek at one of my incomplete robots. Designed around an MC68HC908GP32 microcontroller and featuring a 4-line 20-character LCD display.

Brain Damaged Safety Signs

Past Events:
CIRC banner shown at 2000 Sumo contest CIRC Sumo Robot Contest 2000
The Central Illinois Robotics Club hosted a Sumo robot contest on November 5th, 2000. Bill Harrison announced and judged the matches. Home movies, photos, and a description of the event are posted.

Droolingly fascinating site history.