- 3.3V or 5V TTL voltages (can be set with a jumper)
- Converts TTL logic levels to computer RS232 levels
- Power supplies: 5V, 3.3V, GND (min)
- RX (3.3V or 5V *)
- TX (3.3V or 5V *)
- Mini USB female connection
Choose the 3.3V or 5V by using the black hat to cover the pin in red mark area.