Description

Hardware

The circuit is stand alone and can be connected to the ports B and D off the AVR microcontroller. The circuit consists of three shift registers IC's 74HC595 which switches each column of the displays sequentially on and off for 3ms. PORTB controls the the 74HC595. When a column is selected, the data for the column is put on PORTD, the signals from PORTB are amplified by the ULN2003, and switches the LED's on and off. While each column is swithed on and off seqeuntially, the characters on the display are formed. The PCB contains all the parts except for the microcontroller part. The PCB has to be connected via the two 10 pin flat cable connectors to the attinyboard or the STK500 for example.

Software

The program code is made with the AVR-BASCOM compiler. There is a program for the ATTiny2313, which can show several moving messages on the sign.
There is also a program that is made for the ATMega8 which is more extensive, with this program you can enter a text with maximum 40 characters in a variable in the program, which is shown on the display. It has also a bigger character set.

Downloads

File	Description	File size	Downloads	Last Modified
dot matrix~.bas	AVR BASCOM source file for the ATMega16	12 Kb	1248	25/05/2009 09:29
DOT MATRIX~.hex	hex file for the ATMega16	8 Kb	676	25/05/2009 09:30
dot matrix~.bas	AVR BASCOM source file for the ATMega8	11 Kb	1106	25/05/2009 09:25
dot matrix~.hex	hex file for the ATMega8	5 Kb	613	25/05/2009 09:27
dot matrix~.bas	AVR BASCOM source file for the ATTiny2313	7 Kb	917	25/05/2009 09:22
dot matrix~.hex	hex file for the ATTiny2313	2 Kb	540	25/05/2009 09:24