Based on the Arduino Leonardo, the Matrix Clock is fully compatible with the Arduino IDE. A coin cell powered DS1307 RTCC keeps track of the time and date when the unit is not powered. The Matrix Clock can also play musical alarms through a piezo speaker. Due to its compact form factor the Matrix clock could be fitted in any number of housings - even a pocket watch style housing. If portability is desirable then the unit can be battery powered and a sleep function is available (by taking one of the expansion pins to ground) in order to extend battery life. I've started designing a range of 3d printed housings and will make the .stl files available as I add more.


  • 16x8 LED Matrix display
  • ATMEGA32U4 microcontroller
  • Coin cell powered Real Time Clock Calendar
  • Texas Instruments TLC5920 LED driver
  • 4 Buttons
  • Piezo speaker output
  • Sleep mode input
  • 2 power inputs, USB Micro connector or 6V - 9V DC in. (Normal powered by Vin switches when USB power is present).
  • Compact form factor



Atmel ATmega32u4 in TQFP-44 package

Operating Voltage

5V USB powered or 6V to 9V Vin

Power and communications

USB Micro B


Approx 90mA average during normal operation Max. 300mA

LED Matrix

2x, 8x8, 3mm green LEDs

Clock speed

Microcontroller 16MHz, RTCC 32.7KHz


2.5 KB


1 KB

Flash Memory

32 KB

Expansion Header

Gnd, Vin, 5V, Sleep, Piezo-, Piezo+


66mm wide x 32mm high x 17mm deep



Please check out my web site Carbon Frog for more information about the Matrix Clock and my other projects and products.