I have some special serial transmission and that use single wire with half duplex.
So I need to switch gpio from output to input after transmission. And I need to do that fast!
For now I do transmission with gpio create_wave and encode data to it. And I have script where I switch pin from output to input when no wave is transmitted.
I tried to have two PI pins one for TX and other for RX and resistors to combine them but doesn't work. While transmitting the output need to be totem pole, and while receiving no pullups/pulldowns are allowed.
The my idea mostly work but I have somewhere around 10us to switch and I do that sometime to late. I observe signal on scope and indeed I got timing around 5 to 20us. Is it there a way to do even faster?