Microcontroller Clock

I designed this circuit as part of a design competition for a magazine. I did not win but did get 3rd place and $75 in store credit. The design was used and slightly modified by a Chinese company that makes kits. This is the version from their kit.

32K Sidecar for TI-99/4A Computer

I built this circuit (any many copies for sale) based on a board designed by JediMatt42. This adds 32 kilobytes of expansion RAM to a Texas Instruments TI-99/4A computer. Yes, 32KB not 32MB and not 32GB.

Thermometer Switch

This circuit has cool little circuit is a thermometer switch. It activates a relay whenever the tempature gets above a certain point. Currently, this is used to sound an alarm when the freezer in the garage gets above 36°F.

Beathing LEDS

This circuit has a varible pulse rate that fades the LEDs on and off. This circuit will eventually be used to drive effects on a light theremin and Light Controlled Synthesizer.

Strobe LEDS

This circuit flashes a sequence of red, white and green LEDS. The flash rate and sequence are both controllable. This circuit will eventually be used to sequence a light theremin.

One-Minute LED Timer

This timer was created from a kit and it simply counts to one minute. It has Start, Stop, and Pause buttons.