25MHZ high speed crystal oscillator & 32.768Khz 6PF low speed crystal oscillator<br> V3.0 version began to use lead-free process, the pin header is gold-plated pin header, more environmentally friendly<br> Flash pads have been reserved and USBDisk && FATFFS routines are provided<br> WeAct HID FW Bootloader has been burned out of the factory. It is a special factory test version, and hex is not provided.<br> Support MicroPython programming, provide available MicroPython firmware, see the link for configuration files, but do not provide technical answers!<br> Boards with version V1.3 and above have 3 buttons, reset button, BOOT0 button, and user buttons.<br> How to enter ISP mode<br> 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<br> Method 2: Hold down the BOOT0 key when power is off, and release the BOOT0 key 0.5S after power on<br> 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<br> Serial port mode: use USB to serial port to connect PA9 and PA10 of the core board<br> WeAct HID FW Bootloader<br> No need for USB to serial port, no debugger, no computer driver, just a TYPE-C data cable to complete the firmware download<br> Press and hold theKEY button, click thereset button, LED C13flashes, release theKEY buttonto enter<br> model:STM32F411CEU6 / STM32F401CEU6<br> Colour:black<br> Material:plastic<br> Package Contents:<br> 1 * Development Board<br> Only the above package content, other products are not included.<br> Note: Light shooting 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.