25MHZ high speed crystal oscillator & 32.768Khz 6PF low speed crystal oscillator V3.0 version began to use lead-free process, the pin header is gold-plated pin header, more environmentally friendly Flash pads have been reserved and USBDisk && FATFFS routines are provided WeAct FW Bootloader has been burned out of the factory. It is a factory test version, and hex is not provided. Support MicroPython programming, available MicroPython firmware, see for configuration files, do not technical answers! Boards with version V1.3 and above have 3 buttons, reset button, BOOT0 button, and buttons. How to enter ISP mode 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 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 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.