Instead of using a 'dumb' port expander you could use an 'intelligent' microcontroller e.g. pico board which handles the wiegand pulses, error handling and transmits results via ttl UART to your host RPi. Pico could be bundled with level adjustment, overvoltage protection and eventually optoisolation.
Statistics: Posted by ghp — Fri Feb 21, 2025 7:43 am