Is it possible to use GPIO to sync multiple RasPi video players?
As shown in the picture below, I need to sync 16 RasPi video players. The master RasPi will trigger the video players (
next) on the other 15 RasPi's that are connected to the monitors, and it will also be the master clock for syncing the other 15 video players. I will trigger the master RasPi with OSC messages from my guitar rig (I have this working).
I currently have four RasPi Zero W. Each one is running a video player. By broadcasting an OSC message over WIFI to the four Raspi's, I am able to start and stop the videos and select the next video. But all the videos are out of sync by milliseconds.
I know I can resolve the sync issue using an Ethernet network instead of WIFI, but I already have four RasPi Zero W's and I can order 12 more at $10. I don't want to spend $35 on 16 RasPi 3's when I can spend $10 on 12 RasPi Zero W's.
So, is it possible to use GPIO to sync multiple RasPi video players over distances between 20ft to 40ft?
Since I only need
sync functionality, I'm thinking 4 wires to each Pi's GPIO for transmitting
What do you think?