E104-BT5040U uses nRF52840 chip, and the factory firmware supports CONNET, plug and play. It has rich peripheral resources such as UART, I2C, SPI, ADC, etc., which is convenient for users to carry out secondary development. Use 32M+32.768kHz industrial-grade crystal oscillator. Support Bluetooth 4.2 and Bluetooth 5.0. The module functions and pins correspond to the official nRF52840 USB Dongle module of Nordic, and are compatible with all programs of the nRF52840-Dongle. Product model: E104-BT5040U Operating voltage: 4.3~5.5V Operating frequency band: 2360~2500MHz Chip solution: nRF52840 Transmitting current: 17.05mA Receiving current: 8.27mA Transmitting power: 7.5~8.5dBm Reference distance: 250m Supported protocol: BLE4.2/5.0 Interface mode: USB/1.27mm hole interface: PCB onboard antenna Color: Blue Material: plastic Package Contents: 1 * E104-BT5040U Bluetooth Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.