Text-displaying LED-Matrix Clock

Hi all,

I want to build a stand-alone LED clock that outputs text/symbols and clock display to 10 connected LED dot matrix. The text is transmitted wirelessly to this device and I’ll include some buttons to control clock mode (either text-display mode or clock display mode).

The parts I intend to use are labeled “locked” in the parts list below.

I would like recommendations on what microcontroller and power supply to use on board this stand alone device. The controller is an arduino with a transmitter. The arduino is connected to a raspberry pi 2, where I will be creating the arduino application. The display application running on the microcontroller of the clock will be ‘Parola’.

Currently, I’m unsure of what microcontroller to use and how to build the power supply for the circuit. I’ve got the Matrix to work with the Parola library and now it’s just a matter of developing a program for the clock.

Parts List

Power Supply: ??

Microcontroller: ??

  • Teensy 3.1

Wireless Communication:

  • Xbee Receiver/Transmitter will be with programmer

Display: (Locked)

  • 8x8 LED Matrix (10, data sheet below)

  • MAX7221 Chip (10, data sheet here)

Each display will have at most one row illuminated at a time. The display datasheet says that they can take 25 mA continuously or 160 mA in a 100 microsecond pulse every millisecond (16 mA average). I would guess about 128 mA (8*16) per display so a two amp supply should cover 10 displays. I would use a 5V 2A regulated power supply. Perhaps a 2.1A iPad charger would work.