OpenChessClock

A simple chess clock for the Arduino Uno (specifically the r3, though it probably doesn't matter) that, since it uses embedded-hal, can easily be adapted for other platforms. Basically, it has an up/P1 button, a down/P2 button, and a start/stop/select button for configuration.

Note

On my Arduino Uno r3, there is about a half-second drift per minute of runtime compared to my computer clock.

OpenChessClock even has a web interface for when you want the time to be even bigger! Find out more in /www. It connects to the clock over WebSerial and shows the time, or can operate independently if needed. Screenshots are below.

Pictures and Screenshots

Instructions for use (after set-up)

How do I use this chess clock?

1. Boot the chess clock by plugging it in. It should show a version number and a splash screen.
2. Select the time using the UP and DOWN buttons. Press START to move the cursor from the P1 minute/hour selector to the P1 second selector, etc.
3. On the screen saying P1/P2 to begin, press the button corresponding to the player who will play first. For example, if P1 is White, they should press their button.
4. When players are done with their turn, they should push their button. Continuing from the previous example, when White makes their move, they should press the P1 button.
5. If the game needs to be paused at any time, press the START button. To unpause, press the the P1 or P2 buttons depending on who is going next with the same schematics as the start screen.
6. When the game is over (the buzzer will sound one long beep if it's connected), press START to go back to the time selection screen.

States

State diagram

                                      .----------------.
                                      |                |
                                      v                | UP/DN
┌--------┐     ┌----------┐ ST  ┌-----------┐ ST  ┌-------┐
| Splash | --> | Time set | --> | Countdown | --> | Pause |
└--------┘     └----------┘     └-----------┘     └-------┘
                   ^  ^               | (finish)      | ST
                   |  |               |               |
                   |  `---------------|---------------'
                   |                  |
                   |                  v
                   |        ST ┌------------┐
                   `---------- | Win screen |
                               └------------┘

Time set (time_set.rs):

P1  Set time  P2
0:00:00  0:00:00

Pause (pause.rs):

P1  >Paused<  P2
0:00:00  0:00:00

Top line alternates between P1 Paused P2, START to restart, and P1/P2 to resume .

Countdown (countdown.rs):

[P1]   <<    P2
0:00:00  0:00:00

Finish (finish.rs)

[P1]  Time's up!
0:00:00  0:00:05

or

Time's up!  [P2]
0:00:05  0:00:00

Hardware connections

1. LCD
   LCD RS => Arduino d7 (register select)
   LCD EN => Arduino d8 (enable)
   LCD d4 => Arduino d9
   LCD d5 => Arduino d10
   LCD d6 => Arduino d11
   LCD d7 => Arduino d12
   The LCD backlight cathode and anode should be connected, and the contrast should be set to an appropriate amount using a pot. Of course, make sure the LCD has 5V power (unlike me, who attached it to 2.7V and spent an hour trying to fix it).
2. Buttons
   Down button => Arduino d2 & GND (also functions as P1 button)
   Start button => Arduino d3 & GND
   Up button => Arduino d4 & GND (also functions as P2 button)
3. Buzzer (optional)
   Buzzer anode => Arduino d6

Build Instructions

1. Install prerequisites as described in the avr-hal README (avr-gcc, avr-libc, avrdude, ravedude).

2. Run cargo build to build the firmware.

3. Run cargo run to flash the firmware to a connected board. If ravedude fails to detect your board, check its documentation at https://crates.io/crates/ravedude.

4. ravedude will open a console session after flashing where you can interact with the UART console of your board.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.