Exactly how do you update the DM42 Firmware?

[Didier Lachieze]

The instructions in the DM42 manual are pretty detailed, I've followed them closely and I've successfully updated my production DM42 from firmware 3.0 to 3.1.

The only thing that would need some more writing in the manual is that on a production unit you enter the Bootloader mode via the Setup menu then System and Bootloader, this is what you have to do everytime the instructions ask to switch to the Bootloader mode (there is no BOOT0 or PGM button on a production unit).

My recommendation based on my experience (using a Win10 machine):

• first make a backup of the RAM content in flash with Setup>Calc. State>Save Sate
• then download the libusb, dm_tool (new version 2.3) and your firmware (the flash file not the qspi file)
• then install libusb following the instructions on the SwissMicros site. You just have to do this step once, the first time you want to flash the firmware. Note: on Win8/10 you'll need to enable installation of unsigned drivers, be prepared for that before starting. On my Win10 1709 PC, after looking around and testing different ways I succeeded with the Advanced Boot Option as described here.
• once libusb is installed launch dm_tool and follow the instructions in the DM42 manual to flash the firmware.
  

Note: once the DM42 is in Bootloader mode the only way to exit if you don't flash the firmware is with a paperclip in the Reset hole on the back. This is where your backup will be useful to restore all your data and programs.