Just a sec, I have to administer a ritual dope-slap to myself…
So there’s no pps-yadda-yadda-gpio overlay in the Frite directory - I just got around to noticing this, sorry - so what did I use? And then I started looking for an almost forgotten old thread about getting a PPS signal into the Frite.
I have to give partial credit to this to Rod Stewart, as I had Every Picture Tells A Story playing while eating lunch and then pondering this issue. Last summer really does seem like a long time ago…