25MHZ high speed crystal oscillator 32.768Khz 6PF low speed crystal oscillatorV3.0 version began to use lead-free process, the pin header is gold-plated pin header, more environmentally friendlyFlash pads have been reserved and USBDisk FATFFS routines are providedWeAct HID FW Bootloader has been burned out of the factory. It is a special factory test version, and hex is not provided.Support MicroPython programming, provide available MicroPython firmware, see the link for configuration files, but do not provide technical answers Boards with version V1.3 and above have 3 buttons, reset button, BOOT0 button, and user buttons.How to enter ISP mode 1: Press and hold the BOOT0 button and the reset button under the -on state, then release the reset button, and release the BOOT0 button after 0.5 seconds 2: Hold down the BOOT0 key when is off, and release the BOOT0 key 0.5S after onDFU 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 modeSerial port mode: use USB to serial port to connect PA9 and PA10 of the core boardWeAct HID FW BootloaderNo need for USB to serial port, no debugger, no computer driver, just a TYPE-C data cable to complete the firmware downloadPress and hold theKEY button, click thereset button, LED C13flashes, release theKEY buttonto entermodel:STM32F411CEU6Colour:blackMaterial:plasticPackage Contents:1 * Development BoardOnly 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.