Readme

Basic operation
- Connect the wires to led matrix and RTC as shown in circuit diagram
- Connect led matrix 5V to 5V power supply

Compiler
The project was compiled using compiler version 1.6.9
To set best performance and prevent led flickering:
1. Edit hardware\arduino\avr\platform.txt under compiler directory
2. Change -O in compiler.c.flags to -O3
3. Change -O in compiler.cpp.flags to -O3
To get RTC library download from and follow instructions:
- http://sparks.gogo.co.nz/DS3231_Simple.zip
Upload .ino file to Arduino (Ctrl+U).

Hardware
The buttons are for:
1. Changing:
- Font: time digit font
- Format: 12/24h, seconds or date/temperature
2. Setting date/time if "Format" is pressed when Arduino starts:
- Format button changes value
- Font button continues to next value
Values are:
Matrix bright: 0-minimum, 1,2,3-according to light sensor, 4-maximum (dimmer)
Temper offset: temperature offset (compensate for sensor accuracy)
Year, Month, Day (of month), DOW (Day of week), Hour, Minute

Caution
Do NOT use the Arduino round power connector!
Since Arduino runs on 5V, it has an internal power regulator.
When the 5V is not supplied to the matrix, the leds current is gained from Arduino.
Arduino's internal regulator is not prepared for such currents and gets overheated.

Auto matrix dimmer
The optional hardware parts are for auto dimmer function.
Connect led matrix 5V as shown in circuit diagram.
- The led brightness is automatically adjusted
- When ambient light is stronger - leds are brighter
- When ambient light is darker - leds are dimmed