Arduino Based Dot Matrix Clock

The dot matrix clock was built without the use of a regular Arduino board but uses the ATmega168 with Arduino bootloader and assembled on a breadboard.

An RTC clock compensated by temperature is used by the project as the time is kept by an internal crystal DS232 chip that has built-in temperature sensor. It tries to keep a better time by providing great accuracy around +2ppm in normal conditions. Compared to DS1307, this chip is quite a bit more expensive although both are using the same address over I2C. Two 2.5V 10F super capacitors are used to power this clock which also allows several days of running the RTC clock.

All the values of the clock is displayed in decimal which means that each row, from bottom to top, is worth 1, 2, 4, 8, 16, and 32 as each LED is lit. The final value is obtained by adding the together. The current month, current day of the month, hour, minutes, and seconds, are read from left to right. The clock has no way to be set since the board can be plugged into a computer and communicate serially to the ATmega.

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