The XB122 breakout board for the XM122 module is designed to make the interfaces from the XM122 module accessible for evaluation and debug. With the XB122 breakout board, flashing of XM122 can be done either via the USB to UART interface or the SWD/JTAG interface. The XM122 is connected to the XB122 via a board-to-board connector on the top side of the XB122 PCB. In addition to the board-to-board connector for the XM122, the XB122 comprises a USB micro B receptacle, a 2x5 pin header and a 2x10 pin header. There are two buttons on the XB122, marked DFU and NRST. The NRST button is connected to the reset pin of the nRF52840 MCU and the DFU is used for “Device Firmware Update”. An LDO, a CR2477 coin cell battery connector and a FTDI chip that converts USB into UART is also available on the board.