Skip to main content

Blackpill

Specifications​

  • Microcontroller: STM32F4x1 (commonly STM32F401CCU6 or STM32F411CEU6)
  • Clock Speed: Up to 84MHz (F401) or 100MHz (F411)
  • Flash Memory: 256KB (F401) or 512KB (F411)
  • RAM: 64KB (F401) or 128KB (F411)
  • USB: Type-C connector
  • Bootloader: Typically DFU (Device Firmware Upgrade) bootloader pre-flashed.
  • Form Factor: "Blackpill" board. Pinout is distinct from Pro Micro but can be adapted for keyboard use.
  • Common Firmware: QMK

Frequently Asked Questions (FAQ)​

This page addresses frequently asked questions regarding the Blackpill Controller.

General Questions​

  • What is the Blackpill Controller?

    The Blackpill is a compact development board based on the STM32F4x1 series microcontroller. It's a powerful and cost-effective option for custom keyboard builds and other embedded projects, often favored for its processing power and memory.

  • What firmware is compatible with the Blackpill?

    The Blackpill is most commonly used with QMK Firmware for custom keyboards. Due to its STM32 ARM Cortex-M4 core, it can run more complex QMK features.

Firmware and Flashing (QMK)​

  • How do I flash QMK firmware onto my Blackpill?

    Flashing a Blackpill typically involves putting it into DFU (Device Firmware Upgrade) mode:

    1. Obtain your .bin or .hex firmware file: Build this using the QMK build environment, configured for your specific keyboard and STM32 target (e.g., STM32F411).
    2. Unplug the Blackpill from your computer.
    3. Locate the BOOT0 button (or pin) and the RESET button on the Blackpill.
    4. Press and hold the BOOT0 button.
    5. While holding BOOT0, plug the Blackpill into your computer via USB-C. Or, while holding BOOT0, press and release the RESET button if already plugged in.
    6. Release the BOOT0 button. The Blackpill should now be in DFU mode.
    7. Use a DFU programming tool (like dfu-util or STM32CubeProgrammer) to flash the firmware file.
      • Example dfu-util command: dfu-util -a 0 -s 0x08000000:leave -D your_firmware.bin
    8. After flashing, the Blackpill will typically reset and run the new firmware. If not, unplug and replug it.

    For more general troubleshooting on entering bootloader modes, see the Entering the Bootloader troubleshooting page, though DFU mode steps are specific.

  • My computer doesn't recognize the Blackpill in DFU mode.

    • Ensure you have the correct DFU drivers installed. For Windows, you might need to use Zadig to install WinUSB or libusbK drivers for the "STM32 BOOTLOADER" device.
    • Verify the BOOT0 and RESET sequence was performed correctly.
    • Try a different USB-C data cable (some are power-only) and a different USB port.
    • Check for any shorts or bad solder joints on the Blackpill.

  • My keyboard doesn't work after flashing QMK firmware.

    • Ensure you're using the correct .bin or .hex file compiled for your specific keyboard layout and the correct STM32 variant (e.g., STM32F401 vs. STM32F411).
    • Double-check your QMK configuration files (config.h, rules.mk, keymap).
    • Verify your pin assignments in the QMK configuration match your keyboard's matrix and Blackpill connections.
    • Try re-flashing the firmware.

Hardware Issues​

  • My Blackpill isn't being recognized by my computer at all.

    • Try a different USB-C data cable and port.
    • Check for any physical damage to the USB-C port or the controller.
    • Ensure the Blackpill is receiving power (an LED might light up).
    • If the Blackpill was manually soldered, check all solder joints.

  • One or more keys on my keyboard aren't working.

    • This is often a hardware issue (wiring, diode orientation, switch) or a QMK pin configuration error.
    • Carefully check your hand-wiring or PCB traces.
    • Ensure diodes are correctly oriented.
    • Verify the matrix pins in your QMK config.h correspond to how the Blackpill is wired to the rows and columns.

Layout and Configuration (QMK)​

  • How do I configure my keyboard layout with QMK for the Blackpill?

    Layout configuration is done within your QMK keyboard folder, typically in a keymap.c file. You'll define layers and assign keycodes. Pin definitions for rows and columns are usually in config.h. Refer to the QMK documentation for detailed instructions.

  • Where can I find QMK configurations for Blackpill-based keyboards?

    Search on GitHub for "QMK Blackpill keyboard" or look for projects using similar STM32 chips. Many users share their QMK configurations.

Community and Support​

  • Where can I get more help with my Blackpill Controller and QMK?

    • The QMK Discord server is a primary resource.
    • Online keyboard communities like Reddit (r/olkb, r/MechanicalKeyboards).
    • Forums related to STM32 development.

This FAQ is a starting point. Always refer to the official QMK documentation and STM32 resources for the most accurate information.