Isn't Wiegand interface like beliw:
DATA0 and DATA1 are transmission wires that carry the data and DATAR works as a common ground, with:
When no data is sent, DATA0 and DATA1 wire stay at high voltage (5V)
When “0” data is sent, DATA0 is pulled to low voltage and DATA1 stays at high voltage
When “1” data is sent, DATA1 is pulled to low voltage and DATA0 stays at high voltage
Data rate is 125kHz (if memory serves me right), for (up to) 26-bit of serial data, transferred like described above.
Processing that with an MCP23017 should be possible, but will result in a high interrupt load on the CPU. You can run the MCP23017 i.e. In 400kHz I2C mode, but that will not solve the interrupt issue.
DATA0 and DATA1 are transmission wires that carry the data and DATAR works as a common ground, with:
When no data is sent, DATA0 and DATA1 wire stay at high voltage (5V)
When “0” data is sent, DATA0 is pulled to low voltage and DATA1 stays at high voltage
When “1” data is sent, DATA1 is pulled to low voltage and DATA0 stays at high voltage
Data rate is 125kHz (if memory serves me right), for (up to) 26-bit of serial data, transferred like described above.
Processing that with an MCP23017 should be possible, but will result in a high interrupt load on the CPU. You can run the MCP23017 i.e. In 400kHz I2C mode, but that will not solve the interrupt issue.
Statistics: Posted by aBUGSworstnightmare — Mon Feb 17, 2025 6:23 am