Micro Word Clock v2
A tiny replica of the famous Word Clock, using only an ATmega microcontroller, a DS1307 Real Time Clock and a few passive components to display the time on an 8x8 LED matrix. The letters have been printed onto a transparent sheet and glued over the LEDs to produce a readable time. See the YouTube video here.
- MicroWordClock2-Arduino contains the firmware, including pin definitions for the LED matrix and location of the words in each language.
- EAGLE contains the schematic and PCB design files for the proejct.
- Graphics contains the design for the transparency sheet to place over the LED matrix to form the words, designed in Inkscape. Contributions in more languages are welcome!
Bill of Materials
|Part name||Package size||Reichelt part number|
|C1||220nF ceramic||2012 metric / 0805 imperial||X7R-G0805 0,22µ|
|C2||2.2uF tantalum||3528 metric / B-case||SMD TAN.2,2/20|
|S1||SMD push button||6.2x6.5mm||TASTER 9314|
|XTAL||32.768 kHz crystal||3216 metric / 1206 imperial||32,768 CC7V-12,5|
|LED matrix||8x8 matrix||20x20mm||GYXM-788ASR* (DealExtreme)|
|* Probably any LED matrix labeled 788 should work.|
You will require an In-System Programmer (ISP) to write the firmware onto the microcontroller.
Burning the bootloader and uploading the sketch
Please read these two tutorials if you are unfamiliar with burning a bootloader:
The required procedure is the one described as "AVR on a breadboard" and "Minimal circuit", respectively, as there is no external crystal attached to the microcontroller.
Please download Carlos Rodrigues' Barebones ATmega Chips board configuration file: https://github.com/carlosefr/atmega (instructions inside)
The ICSP header on the Micro Word Clock PCB is the standard layout described here (Fig. 2).
quistoph has made a Dutch layout.
Tanguy Rewers independently came up with an alternative Dutch layout (labeled as dutch2).
This project (both software and hardware) is published under a Creative Commons BY-SA 3.0 License.