Thread: Convert fenix 5S/5/5X Plus to D2 Delta S/Delta/Delta PX

Originally Posted by Serhito

Thank you so much !! Any way to donate for your work ?

I'm happy if you're happy. No donation necessary.

Originally Posted by vscvsc

If I understand correctly I should be able to flash a Fenix 5X Plus to a D2 PX by downloading the current D2 PX firmware (e.g. D2DeltaPX_610.gcd) and flashing it via Garmin's web updater. Years have past, is there reason to believe Garmin has changed anything in the Fenix 5 firmware that prevents flashing D2 firmware?

That's not quite right. Garmin firmwares check whether the firmware was meant for that device by verifying the hw_id (device/model number) and some flags in the firmware files. If they don't match, the firmware isn't installed - even if the hardware is exactly the same. That's why I've modified the firmware files on the MEGA share so e.g. the hw_id and flags of the D2 Delta firmware match those of the Fenix 5 Plus.

Originally Posted by vscvsc

The first post suggests conversion to rgn is required. When I use the rgnTool to write a rgn, the tool complains boot.bin should be in section 1...hope you know what you are doing. Should I assume this message can be ignored?

Please don't use that method anymore. It worked for converting a Fenix 5 Plus to a D2 Delta, but was a one-way thing as e.g. the D2 Delta bootloader doesn't have the Preboot mode needed to force-flash the RGN. The method using the modified firmware update files is much safer and works in both directions.

And as Serhito pointed out already, you can't add hardware features this way. If there's no SpO2 sensor (i.e. a red led) on your watch, a firmware change can't add it. Also, flashing e.g. the D2 Delta firmware onto a D2 Charlie won't work either as those have different hardware specs and you'll most probably end up with an expensive paperweight.