You got it (probably the post title helped too): a scoreboard.
For those not familiar, a traditional one looks like in the photo below (click on it to see it bigger).
It may look simple, but it provides a lot of functionality:
- display 2-digit home score;
- display 2-digit visitor score;
- countdown timer, with the starting time configurable/settable; timer displays mostly minutes and seconds, but under 1 minute, it displays seconds and tenths of a second;
- stop/resume the countdown;
- display round/period; number of periods is configurable/user-settable;
- buzzer sounding at the end of the round, game or on demand;
- penalty timers for up to four players (that also stop/resume with the main timer);
- functions as a clock when not used in a game.
An easy and quick way to build a home-made hockey scoreboard is to re-program a dual-display (16 x 64 pixels) Wise Clock 4. The scoreboard should be controlled wirelessly, from a distance of at least 10 meters (which disqualifies infrared remotes and also the most common Bluetooth, "class 2"). Potential solutions for the scoreboard remote control are:
- XBee
- good distance range;
- not cheap;
- reliable communication;
- requires building and programming a remote control device;
- already hardware-supported by Wise Clock 4 board;
- RFM-12
- good distance range;
- cheap;
- reliability probably ok for short messages;
- requires building and programming a remote control device;
- uses SPI interface, requiring some hardware hacking;
- RF 4-button key fob
- cheap
- easy to integrate
- does not require any software support;
- reliability at distance greater than 10m (?);
- no need to build the remote control;
- unfortunately limited to only 4 buttons;
- WiFi
- cheap (ESP8266)
- works as access point; user connects from smart phone or tablet, to access HTML form pages to type/input commands;
- requires extra coding;
- no need for extra remote control device (since using phone or tablet);
If using buttons, at least 4 are required to cover the minimum functionality:
- reset scoreboard - D0;
- start/stop/resume countdown timer - D1;
- increment home score - D3;
- increment visitor score - D2 (available) or D22 (re-routed)
This is how the prototype scoreboard works on my desk:
The software is a branch-out of the Wise Clock 4 main software (using the same libraries, classes and functions, but in a separate .ino file). I created a new font (file fontFull.h) for the score digits, defined in a 8x16 matrix.
To add extra features ("clock mode", "chrono mode", message scrolling etc), more buttons/commands would be required on the remote control. Which means that the RF 4-button key fob is barely enough for now, and another solution must be implemented. My next favourite is the RFM-12, a topic for a future post.