Here’s an interesting kit put together just to help you work on your SMD soldering skills. It’s got 49 SMD LEDs on the front with a programming header and switch jumper. The back has an ATtiny26L and a coin cell. At only 3V, power management is essential; all of the example programs are only addressing one LED at a time (imperceptible to the human eye). If you turn on too many LEDs at the same time, the voltage drop could cause the AVR to reset. Included example programs are a scrolling marque, bouncing balls, and Conway’s game of life. SparkFun has tutorials for regular SMD soldering and using a reflow skillet. The video below shows the kit builder attaching just one LED using the heat and slide method.
matrix129 Articles
3x3x3 LED Cube
[portreathbeach] built this simple 3x3x3 LED matrix. It uses a PIC16F690 in a ZIF socket for the brains. Each layer has nine LEDs with the cathodes tied together. The anodes from each LED are connected to the LED below. The LEDs are multiplexed so that even though all layers appear to be on, they’re being addressed individually. He’s included software, so you can build your own animations. Video of the matrix in motion is after the break.
Spectrum ZX Laptop
[Jim] sent in this interesting laptop modding project. He started with a Spectrum ZX and a Toshiba Libretto 110. The libretto kept its brains, but the lower case and keyboard was replaced with the ZX hardware. Since both machines use matrix style keyboards (but different matrix layouts) he was able to create a passive adapter circuit to match things up.
