Category Archives: charlieplexing

A Game That Does More With Less

[David Johnson-Davies] created a minimal Secret Maze Game using a single ATTiny85 and a few common components. This simple game uses four buttons, four LEDs, and a small speaker. The player moves in the four cardinal directions using buttons, and the LEDs show walls and corridors. If an LED is lit, it means the path in that direction is blocked by a wall, and attempting to move in that direction will make a beep. When the player reaches the exit, a short victory tune chirps from the speaker.

Since the ATTiny85 has only five I/O lines, [David] had to get …read more

Continue reading

Posted in ATtiny Hacks, attiny85, AVR, charlieplexing, game, led, led hacks, maze, minimalist | Leave a comment

New Method for Measuring Lots of Resistors Using Very Few Wires

[Daqq] is back at it again with the linear algebra, and he’s now come up with a method for determining the resistance of lots of resistors using little of wires and loads of math.

Like any reasonable person, [daqq] decided it would be fun to “solve one of those nasty [electrical engineering] puzzles/exercises where you start out with a horrible mess of wires and resistors and you are supposed to calculate the resistance between two nodes.” You know, just an average Saturday night. At the time, he was also fascinated by Charlieplexing – an awesome technique that either allows one …read more

Continue reading

Posted in charlieplexing, conductometric sensors, hardware, linear algebra, math, multiplexing, resistors, systems of equations | Leave a comment