fblumenberg/micro-word-clock

Displaying the time in 8x8 pixels

Micro Word Clock v2

Description

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.

Directory structure

• 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
IC1	ATmega328P-AU	TQFP-32	ATMEGA 328P-AU
IC2	DS1307Z+	SO-8	DS 1307Z
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)
PCB		20x20mm	OshPark
* 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:

• http://arduino.cc/en/Tutorial/ArduinoISP
• http://arduino.cc/en/Tutorial/ArduinoToBreadboard

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).

Contributions

Carl Monk has built his own version using a Unicorn HAT.

quistoph has made a Dutch layout.

Tanguy Rewers independently came up with an alternative Dutch layout (labeled as dutch2).

Featured on

• Hackaday
• Gizmodo
• The Atmel Blog

License

This project (both software and hardware) is published under a Creative Commons BY-SA 3.0 License.