Stopwatch / Status Display

This shows a combination status display / stopwatch panel that provides visual feedback on the progress of our challenge runs on the videos. The display is built from (2) 32×64 LED matrix displays, giving a total field of 32×128 pixels. It uses an Adafruit MatrixPortal to drive the panel and to connect to an MQTT broker over the network to receive commands.

While the unit was built specifically for the PiWars challenges, it could be easily used for any competitive event that would benefit from a display of status messages and event timing.

The panel is 130×500 mm in size, using the 4mm pitch display panels from Adafruit, but 3mm pitch or 6mm pitch panels could be substituted to achieve different physical sizes at this resolution, or the field “width” or “height” can be extended by adding additional panels, with minimal software changes.

Software and complete documentation including message protocols is available on Don’s Tech Stuff site.

Those who watched our challenge videos will remember that there was a bug in the stopwatch code that caused it to “run slow”. The bug is fixed in the posted code. It was a careless error, born of rushing to get this ready for filming, but its a great reminder that (1) rushing is rarely a good idea, and (2) code reviews ARE ALWAYS a good idea.