Thankyou for the pointer - I'd overlooked that I had added an automatic shutdown in the original (about 3 or 4 years ago!) and carried it forward.There is nothing in the default install of Raspberry Pi OS that will claim GPIO21 as a "shutdown".
Presumably you've added an overlay that is claiming the GPIO - provide the full content of config.txt.
So I asked the wrong question; it should be "is there a way to read the pin status in application software as well as using it for the shutdown function?". I vaguely recollect reading in a thread that this is a change, and that tasks now gain exclusive access to a pin, so probasbly not possible.
I've currently declared all the I/O I want to use in a single R/W block; could I add another I/O block with GPIO21 as R/O?
Thanks
Statistics: Posted by stevend — Sun May 26, 2024 8:11 pm