...
The default baud rate of the RS-232 interface is 115200, with no parity, 8 data bits, and 1 stop bit. These settings can be configured in the software. The serial interface supports TX, RX, and ground only—RTS/CTS hardware flow control is not supported.
A serial cable plug that is inserted into the 3.5mm jack should use the following signaling:
- Tip: Transmit
- Ring: Recieve
- Sleeve: Ground
The following diagram illustrates the behavior of the TX and RX signal:
...