Led Sign with MMC Memory

AVR Project 조회 수 21326 추천 수 50 2004.03.04 15:37:08




Led Sign with MMC Memory Card



At the beginning this project was to buy a led sign to interface with my home automatisation network. This automatisation network display information like temperature, wind speed, humidity, etc.  I had bought on Ebay a Led Sign but when I received it I got a surprise! There was no serial port to program messages... After a couple of days, I look inside to see how it was built.  The principle of operation is simple you have just 160 bits shift register with drivers for leds. I removed the old CPU from the LED sign and connected a couple of wires to the shift register (column driver) and the row driver to an ATMega128. The main reason why I chose to use an ATMega128 was the need of a large amount of RAM.  I decided to use a MMC memory card to store all the messages for 3 reasons: low cost, SPI interface and a lot of space for messages.



  • 3 Colors messages
  • 5 Scrolling speed
  • Serial port for uploading messages




New CPU Board

What it's look like


Sources codes & Schematics

-CPU Shematic in PDF format

-LED Board Shematic in PDF format

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