After getting a couple of flashing lights working on a microprocessor, the next fun project is generally building some kind of Matrix.  At first I built a 5×5 LED matrix which was relatively simple to solder together.  When trying to make one much larger, the task because significantly more complex.  That’s when I decided to build a LED Matrix Shield for the Arduino which did not use Charliplexing, like the LoL shield.  I wanted something that was simpler to understand and (ultimately) code for.  Unfortunately, 5mm LEDs means 8 columns x 6 rows, instead of the traditional 8×8.

Accurate RTC Shield with Kapton Stencil
Accurate RTC Shield with Kapton Stencil
For the past couple of weeks I have been working with the DS3231 Maxim. This chip is a I2C based RTC with an integrated temperature compensated oscillator and crystal.This means despite changing temperature conditions, it will maintain a very accurate track of time. If you’re interested in the first rev of the PCB, let me know. I have a few available. They are functional, however, the prototyping area came bad.I have a set of new ones with a proper prototyping area, reset button, and power LED in process.

Check out more on the  Accurate RTC Shield Project Page