I’ve been testing PTP (Precision Time Protocol) support in a few Raspberry Pis at home and thought “why not use the UTC-traceable 1 Pulse-per-second (1PPS) output from my GPS breakout-board to drive a relay that flashes some Christmas tree lights?” 🙂
Although the GPS’s 1PPS output is sync’d to UTC within some 10s of nanoseconds the energising of the relay coil and the startup delay of the LED lights AC/DC converter probably add a few milliseconds to the overall delay…
Human perception of delay between audio/visual events is limited to at best a resolution of around 20ms so to the human eye/ear the flash/click looks/sounds in sync 😁
Room 7609 