The next version of Signals for Android devices is now available on Google Play.
This is an upgrade that adds support for some USB serial relays (HW-667s or many of those with a CH340 controller). So the app can now trigger start signals via a simple USB relay or via an Arduino.
Signals is a free and open source app that automates the sound signals for dinghy race starts. You can use it with your own race hooter using simple components such as 12 volt car horns and batteries combined with a cheap USB relay or Arduino to connect to the app.
Some of the stress is taken off the race team with the Signals app providing automatic timing of sound signals plus the ability to make those extra manual hoots for over-the-line, general recall and shorten course.
The source code can be found here (and includes the app, if you want to install it directly rather than via Google Play).
If you need some help building a race hooter, Ian will be posting a video on the blog in the next few weeks to demo what components to buy and how to put them together to make your own automated Signals box.