Boards with version V1.3 and above have 3 buttons, reset button, BOOT0 button, and user buttons. How to enter ISP mode Method 1: Press and hold the BOOT0 button and the reset button under the power-on state, then release the reset button, and release the BOOT0 button after 0.5 seconds Method 2: Hold down the BOOT0 key when power is off, and release the BOOT0 key 0.5S after power on DFU mode: just use the data cable to connect to the computer, if there is a problem of unrecognized, you can properly heat the chip (25 Celsius), and then re-enter the ISP mode Serial port mode: use USB to serial port to connect PA9 and PA10 of the core board WeAct HID FW Bootloader No need for USB to serial port, no debugger, no computer driver, just a TYPE-C data cable to complete the firmware download Press and hold theKEY button, click thereset button, LED C13flashes, release theKEY buttonto enter model:STM32F401CEU6 Colour:black Material:plastic Package Contents: 1 * Development Board Only the above package content, other products are not included. Note: Light 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. STM32F411 STM32F411CEU6 STM32F4 Learning Board