Guru
Joined: 11/02/2018
Location: AustraliaPosts: 3313
| Posted: 07:52am 27 Sep 2022 |
I can confirm that the OC option does not work.
Even with a 1k5 resistor to ground the voltage only drops to 3.23V, that is active high.
A hardware solution is to put a diode in series with the pin, cathode to the pin.
If the pin is used for two way comms add a 100k across the diode. Such a high value may slow things down so some experimentation may be needed.
Peter must have found a way around it for the PS/2 keyboard.
Edited 2022-09-27 18:05 by phil99