If a new firmware is released, you can easily upgrade your Midikraken to the most recent version via USB. First, download the firmware image from here, then follow the steps below depending on your operating system. Do not unplug the device during the flash procedure or you might damage the firmware.
If, however, your Midikraken failed to upgrade and now is in an inoperable state and does not show up as USB device, read the rescuing section below.
The midikraken firmware is currently in its early beta phase, so there could be bugs. If you find one, please check the issue tracker whether it was already reported. If not, please report it through the issue tracker or via mail.
Please note that firmware upgrades can occasionally lose your settings due to changes in the save format. One or two such breakages will happen with one of the next firmware upgrades. Such breakage will be announced in the release notes.
Port numbering is currently non intuitive and is subject to change in one of the next releases.
Only if you are flashing the firmware for the first time, give your user permission to flash the device by executing the following as root user:
gpasswd plugdev -a YOUR_USERNAME_HERE # note: if the plugdev group does not exist, replace it by "uucp" in all steps
echo 'SUBSYSTEMS=="usb", ATTRS{idVendor}=="1209", ATTRS{idProduct}=="2e7f", GROUP="plugdev", MODE="0666"' >> /etc/udev/rules.d/50-dfu.rules
udevadm control --reload
To actually flash the firmware, as your normal user account, extract the firmware zip, open a
terminal, navigate to the extracted files and execute the flash.sh script.
Unpack the firmware package.
If you are flashing the firmware for the first time, you need to install the WinUSB driver first.
To do so, execute the install_driver.bat script from the firmware package with the device attached.
This will reset Midikraken into bootloader mode, and then open Zadig. Open the Options menu and check
"List All Devices". Then, from the combo box, select "Midikraken bootloader". Next to the green arrow,
select "WinUSB". Then click "Install driver" and close Zadig.
Now you are ready to flash the firmware by executing flash.bat.
TODO. Probably you want to use brew to install dfu-util, send the bootloader.syx
SysEx to output 1 of your midikraken somehow, and then upgrade the firmware as described in the Linux
section using dfu-util.
If the device does not show up via USB and the display does not work any more, likely the firmware was damaged.
Midikraken contains a bootloader, i.e. a small program that allows the device to self-update via USB. This bootloader is usually called from the firmware, but if the firmware is damaged, it is possible to force Midikraken into the bootloader mode.
To do so, unscrew the top shell and carefully detach the DIN5+display assembly from the TRS board. Be sure to not rip out the cable. You now are able to view the top side of the STM32 blue pill board. Locate the pins labelled "B12" and "G" that are left and right of the USB port. Unplug the USB cable, then use a pair of tweezers to connect the "B12" pin with "G". Plug in the USB cable while shorting these two pins. Now a "Midikraken bootloader" device should show up. Proceed to flash the firmware as usual.
In the highly unlikely event that you have a defective bootloader, you will need additional hardware to re-flash the bootloader. This can be done either using a UART adapter or using a JTAG/SWD debugger, e.g. a STLINK or a Blackmagic probe. Follow these instructions to build and flash the bootloader.