Building the LED Halloween Eyes

Overview

The project utilizes four 5 x 7 dot matrix display in order to produce the LED Halloween Eyes that is capable of blinking very often.

Details

The design of the circuit uses an LM Driver platform where a pair of terrifying disembodied eyes was represented by four 5 x 7 dot matrix displays. Along with the 2 complete LM Driver modules is a microcontroller that performs the stepping through their sequence. The board is partially populated with the programming interface together with the 4 LED matrices. The central microcontroller which sends out the LM Driver commands through a bit-banged SPI bus is used to control the displays on either end.

An Atmel ATmega169 microcontroller is responsible for driving each display module. The multiplexing of the displays is being handled by the microcontroller as it accepts an extensive command set. Each LED matrix has a maximum of 2 LEDs ON simultaneously since the displays are heavily multiplexed. One feature of the LED displays is the dual color capability.

A tiny ISP module is being used to do the programming as it is attached to the eyes module together with the module development next to it.