I have situation where i need to capture wiegand26 signal. I use it on single twisted pair. But i get a lot of AC noise in UTP cable Cat 6. Shield is not connected anywhere.
VCC for is from wall AC/DC adapter 12V/1000mA. My tester battery is low so it shows 20V with no load... I guess batteries, but i will check again and change it ASAP :)
I added also
10k ohm resistor to pull signal to ground, but it doesn't. The lines in idle is (or should be) +5V. On data transmit it should be 0V.
This is the setup
at the Arduino side i get this