@PropellerHat said in Upgrading from RRF1.21 to 3 with SD only:
Last time I updated the firmware it was very easy, just putting the file on the SD and commanding the update from Paneldue. I have never had the printer connected, always used the SD only.
That is still possible. The only difference is that in addition to the firmware bin file, you might also need some IAP files on the SD card. Then send M997 from the paneldue to initiate the update.
Upgrading to 2.0 and then 2.05.1 would be pretty straight forward and wouldn't require many changes to the config file. There may be some changes required if you use corexy and maybe some homing file changes. Nothing dramatic. Reading through the update notes would be recommended.
Upgrading to RRF3 would require config file changes.
Sticking at 1.21 is still an option of course.