Wireless-Tag WT51822-S4AT nRF51822 BLE 4.2 Module

Connect the module's UART_TXD and UART_RXD pins to your host microcontroller's UART RX and TX pins at 3.3V TTL logic levels. Power the module with a stable 3.3V supply. By default, it often operates in a transparent serial bridge mode, so any data sent from your MCU's UART will be transmitted via BLE, and data received via BLE will be output on its UART. You may need to configure the baud rate (commonly 9600 or 115200) via specific AT commands if supported by the pre-loaded firmware.

Yes, you can update the firmware using the standard Nordic Semiconductor SWD (Serial Wire Debug) interface. You will need a compatible SWD programmer/debugger like a Segger, ST-Link (with appropriate voltage adaptation), or a dedicated nRF51822 DK. Development is typically done using the Nordic Semiconductor nRF5 SDK or Arduino core for nRF51 within the Arduino IDE or PlatformIO. The process involves connecting the SWDIO, SWDCLK, VDD, and GND pins to your programmer and using the `nrfjprog` command-line tools or the IDE's upload functionality to flash the new .hex file.

The module's integrated PCB antenna typically provides a range up to 45 meters in open space under Class II power settings. To extend the range, you can solder a 2.4GHz external antenna (like a whip or ceramic antenna) with a 50-ohm impedance to the designated antenna pad. Ensure you use a matching RF trace design on your PCB and select an antenna with an appropriate connector or solder pad. This can significantly improve link reliability and distance, especially in environments with obstacles or interference.