![STC15L204 + NRF905 wireless serial port module wireless passthrough module wireless STC15L204 + NRF905 wireless serial port module wireless passthrough module wireless](https://www.bifelectronic.com/2545-large_default/stc15l204-nrf905-wireless-serial-port-module-wireless-passthrough-module-wireless.jpg)
1.On board STC15L204EA microcontroller chips .
2.On board NRF905 wireless module.
3.On board UART interface, used to implement the serial communication.
4.On board 5 V to 3.3 V AMS1117-3.3 chip.
5.All spare I/O are lead to, and mark the I/O name.