How to Flash Q3 with Entire Chip Erase by Using STM32CubeProgrammer
Step 1: Install the STM32CubeProgrammer here (Choose the file that fits for your computer system and unzip the file.)
Note: (If the installation fail to install on Mac, please following the steps below. Or you can refer to the document here. For Mac users please refer to 1.2.3 in the document, for Windows users please refer to 1.2.4 in the document.)
Step 1.1: Right click the app and choose "Show Package Contents" >> "Contents" >> "MacOS". In the "MacOS" section you will see the Terminal and click it.
Step 1.2: Then the Terminal window and the App Installation Wizard window will pop up. Follow the instruction of the Wizard window to install the STM32CubeProgrammer app, (Keep clicking "Next") and it would be good to save the app file in Applications.
Step 1.3: Once the installation is done, you can find the STM32CubeProgrammer file in the Finder >> "Applications". Click the App folder and find the STM32CubeProgrammer App, and now the app can be opened.
Step 2: Download Q3 Firmware File
Step 3: Run the STM32CubeProgrammer
Put the keyboard into DFU Mode
Unplug the power cable from Q3, then remove the space bar keycap to hold down the reset button and plug in the power cable.
Connect the keyboard with STM32CubeProgrammer
Choose the connection way "USB“ and click the button (As the following picture shows) to refresh devices.
It will show as the picture below if the keyboard in DFU mode is detected correctly.
Then click the "Connect" button and the app shows as below.
Step 4: Read the firmware from keyboard
Change the size to "0x20000", and click "Read" button, then click the triangle arrow on the right of "Read" button to show menu to save to file, the size of saved file should be 128KB. Please send the file back to Keychron Support to debug and help to improve products.
Step 5: Flash the firmware to the keyboard
Click the "Download" button to switch to interface below.
Click as the picture shows below. (Note: Click the "browse" to select the firmware fits for your keyboard)
Now the keyboard should work fine.