A GPIO timer for DerbyNet server (https://derbynet.org/). Please note that I am not affiliated with that project in any way nor do they endorse this timer. I have tested with version 8 of derbynet server.

This project uses golang to send timer messages to the derbynet server application. It listens for GPIO pin changes. Use the build.sh script to build the executable. Install docker and use go.sh run github.com/Nescient/gpio-timer to run the executable. Alternatively, install go to build and a new enough glibc for running.

The current set up is using the Libre Computer Board ROC-RK3328-CC on pins 3, 5, 11, 13 (four lanes), and pin 8 (for the gate). See the top of gpio.go for pin constants. The GPIOs are set to pull up and trigger on the falling edge (which is what works with the beam sensors I tested). Our project used Adafruit IR Break Beam sensors: https://www.adafruit.com/product/2167.

• https://hub.libre.computer/t/libre-computer-wiring-tool/40
• https://rockchip.fr/RK3328%20datasheet%20V1.2.pdf

• https://derbynet.org/builds/Installation-%20Windows.pdf
• http://drakedev.com/pinewood/
• https://derbynet.org/builds/docs/Developers-%20Timer%20Messages.pdf

• https://stackoverflow.com/questions/51310506/using-c-libgpiod-library-how-can-i-set-gpio-lines-to-be-outputs-and-manipulat