1. Operating voltage: 3.3V~5V
2. Interface:
   - One-wire UART x 2
   - BMCOM x 1
   - I²C x 2
   - UART x 4 (configurable baud rate: 230400bps Max.)
3. IC: WK2114
4. Parity format: parity bit / no parity bit
5. Stop bit: 1 bit or 2 bits
6. Receive/transmit FIFO: 256 bytes, the byte number can be queried
7. TX / RX pin status: enable / disable
8. Dimension: 67 x 53.34 x 16.8 mm
9. Net weight: 23.7g

You can insert the product into an Arduino UNO or the BMduino-UNO, BM53A367A, without using an external cable.

The product offers UART, one-wire UART, I²C and BMCOM interfaces.

1. UART interface: expanding the main serial port to four sub-serial ports. You can configure the baud rate, check format, and stop bit for each UART sub-serial port.
2. One-wire UART interface: communicating by using the SoftwareSerial library of BMduino-UNO BM53A367A.
3. BMCOM: communicating via hardware I²C or software UART. It is necessary to use it with the above software, SoftwareSerial library.
4. I²C interface: simulating I²C master via IO pins.

Front Side

Rear Side