Is there any equivalent of a rpi gpio pin anywhere on this main board? I only need a single gpio pin.
My use case is wiring in an external GPS receiver, for the purposes of a precise time source for local my chrony instances. I have 3 of these little GPS boards total (found a pricing mistake where a 3 pack was cheaper than buying 1 even), and 2 are successfully deployed onto raspberry pis. They use the PPS pin from the little GPS board into a GPIO input on the pi, to give the Pulse Per Second (PPS) input to chrony for ~50 nanosecond precision. This means the quite variable USB latency (and therefore random-ish NMEA offset) is completely bypassed. Hoping to do the same with my Framework home lab server to make a triple redundant ring of GPS disciplined peers on my LAN.
Yes, I can do a serial/ttl to USB adapter, but this kind of smears the precision of the PPS signal. I would vastly prefer a direct hard wire input on the main board that skips the USB stack entirely.
Thanks, brain trust.