Update README.md

README.md

@@ -11,18 +11,18 @@ Configuration for the 8MHz version of Blackpill_f411 provided by the [Xecut hack
 ## Initial Flash
 
 1. Clone this repository:
-    ```
+    ```sh
     git clone --recurse-submodules git@github.com:He4eT/cantor-mx-tastatura.git
     cd cantor-mx-tastatura
     ```
 2. Connect the **left** controller to your computer using a USB cable.
 3. Start the flashing process (Docker required):
     - For **8MHz Blackpill_f411** controllers:
-      ```
+      ```sh
       make flash blackpill=f411_8mhz half=left
       ```
     - Otherwise:
-      ```
+      ```sh
       make flash half=left
       ```
 4. Use the onboard `BOOT0` and `NRST` button to put the board into bootloader mode:
@@ -31,6 +31,7 @@ Configuration for the 8MHz version of Blackpill_f411 provided by the [Xecut hack
     - release the `BOOT0` button.
 
    For additional details, refer to [STM32 Black Pill](https://land-boards.com/blwiki/index.php?title=STM32_Black_Pill).
+   See also the [troubleshooting section](#Troubleshooting).
 5. Repeat the process starting from step 2 for the **right** half.
 6. Download the [Vial configurator](https://get.vial.today/).
 7. **Linux Only**: Configure [udev rules](https://get.vial.today/manual/linux-udev.html) for the first launch.
@@ -46,7 +47,7 @@ from the [vial-qmk](https://github.com/vial-kb/vial-qmk/) repository is used.
 
 ### My Opinionated Layout
 
-```
+```text
 ./layouts/odd_cantor_tastatura.vil
 ```
 Check out [this forum thread](https://forum.dmz.rs/t/cantor-mx-keyboard/700)
@@ -66,8 +67,20 @@ for some explanations.
 
 ## Case
 
-```
+```text
 ./things/case_slim.stl
 ```
 The [Cantor MX Slim Case](https://www.printables.com/model/996711-cantor-mx-slim-case) is
 a remix of the [Cantor MX Case](https://www.printables.com/model/707238-cantor-mx-case) by [@JellyTitan](https://www.printables.com/@JellyTitan).
+
+## Troubleshooting
+
+### dfu-util: Error during download
+
+Some versions of the STM32 Black Pill are [unable to be flashed over USB using DFU mode](https://github.com/qmk/qmk_firmware/issues/17576).
+In this case, you can usually flash the firmware using an ST-LINK device instead:
+
+```sh
+make flash half=left
+st-flash write ./vial-qmk/custom_cantor_f401_vial.bin 0x8000000
+```