Features
- Multiplexed 7 segment display
- Accurate time keeping with RTC and battery backup (keeps time when powered off)
- Menu and change value/show temperature buttons
- Temperature displayed to 1 decimal point
- Automatic adjustment for British Summer Time (BST)
- Powered via 5v USB
- Scrolling messages
Building
- The circuit is simple to build but connecting all the 7 segment LEDs get tricky.
- Follow the attached schematics or breadboard view
- I CNCed a circuit board so that the 7 segment digits would fit the window in the clock exactly. These files are attached.
Coding
The source code is attached. I used Sublime Text for editing and Arduino IDE 1.6.5 for uploading
On Arduino IDE 1.6.7 I had to add old the Button library 0.2.2.
Odd, but it works.
DL https://playground.arduino.cc/uploads/Code/Button/index.zip