When I thought of doing a Chess Clock with Arduino, the goal was to build using simple programming without use class and work with the AVR register. The base used was Arduino Reference. The most difficult thing was to manipulate the timer using only the Arduino millis (). The idea is the project can be useful by the beginner students of the Arduino.

Step 1: Features

Complete timer adjust using keypad to hour, minutes and seconds, of 1 sec up to 10 hours
Storage last adjust in eeprom
Time control by Sudden Death or Increment of up to 99 seg
Pause timer using any keypad key and release using game buttoon
Sound to check that game button was pressed and when game is over

Step 2: Parts

Arduino Uno or any other
2 Push button R13-502
Buzzer
For LCD shield board, can be used LCD Keypad Shield or DIY using:
- LCD 16x2
- 6 Tactile Push Button Switch
- Universal Circuit Board
- Row Pin Header

Step 3: Circuit

The most complicated circuit is the LCD Keypad Shield, if this piece is bought ready the rest is so simple.

schematics.fzz
Download

Step 4: Files

Arduino code: https://github.com/naldin/ArduinoChessClock

Arduino stand: https://www.thingiverse.com/thing:3043109

Bauhaus Chess Set: https://www.thingiverse.com/thing:2161468

Step 5: Update - 2021 January

The diference in this new stand is that I used an Arduino Pro Mini instead Arduino Uno. As Pro Mini use the same Atmega 328 nothing was changed in code or electronics connections:

Arduino Stand Definitive Edition: https://www.thingiverse.com/thing:4710255