decade counter

16 Articles

LED Matrix With A Gross Of Pixels

July 21, 2010 by 19 Comments

This LED matrix is arranged in a 24×6 pattern for message scrolling. There’s no etched boards here, making us wonder where [Syst3mX] found protoboard this long. He’s using an Arduino to drive the demonstration (clip after the break) but you can use any microcontroller with this setup. That’s because he’s using three shift registers for column data and a decade counter for row scanning, requiring just five control pins.

While you’re going to the trouble of ordering components, maybe you should try your hand at building a touch sensitive LED matrix too.

Continue reading “LED Matrix With A Gross Of Pixels” →

Clock Sans-microcontroller

April 3, 2010 by 20 Comments

This clock requires no microcontroller. It’s actually a digital logic counter that functions as a timepiece. [BlackCow] used six decade counters to track seconds, minutes, and hours. The output is displayed on four 7-segment digits using BCD-7-segment decoders that you can learn about in our binary encoded decimal post. The actual timekeeping is done by a quartz clock circuit he pulled from a Mickey Mouse clock. This would be a perfect circuit to build in a digital logic simulator, just follow the schematic and learn as you go.