I have a simple resistor voltage divider as an interface between a PC's (TxD) port (±12-V) and the Keyfob's (RxD) port (±3-V).
[ PC (RS-232 - TxD) ] ---> [ (±12-V) | VOLTAGE DIVIDER INTERFACE | (±3-V) ] ---> [ Keyfob (UART - RxD) ]
The data received in the Keyfob UART buffer is corrupted; where a hex 0x01 is received as 0x7f.
Can the cc2541 Keyfob UART hardware handle bipolar levels or do they need to be unipolar? Please advise. Thanks.