So… I spent a long time following tutorials etc and got everything built correctly for my A20, with the latest version of Merlin - 2.1.2.5 (I was on a 2.0 bugfix, but the reason I’m doing this is I want to add the 3d touch bed levelling, which was not enabled). Working on macOS so learned what was needed for avrdude to upload (PlatformIO, just couldn’t get the port working after an hour, and I’m happy using a CLI).
The printer boots up fine. But I had foolishly thought that I would be able to use auto home, the printer would find the three zero stop switches, I could save those settings to the EEPROM and start using it again.
This, as you can imagine, is not what’s happened. The Z height was at (say) 150mm above the bed (I left it up there in case it was unsafe and I’d have time to turn the printer off it it did something crazy when I flashed).
So, I have a situation where I’ve spent maybe 2 hours finding disparate old threads, and nothing I can find tells me how to fix this. At the moment the firmware thinks that zero is the current position and (sensibly) won’t go below it. The boot up display shows flashing ?? for each of the axes.
Can someone give me some direct instruction on how I can fix this? I’ll be honest, I’m not well (no details, but short life expectancy), and maybe my searching isn’t as good as it should be. But I can’t find a “This is how you restore sanity after you’ve upgraded Merlin” section. Once that’s in place, I’m good to go - once the touch hardware arrives I’m confident I can get all that set up and running, and I’m generally happy to spend a couple of hours searching and trying stuff. But the only references I’ve found have been 6 years old on Reddit and said things like “simply eeprom the values” or something not particularly helpful like that, and no reply has been given in that thread.
Any clear help (of details or even the concept that is needed) would be really useful. Thanks in advance.
UPDATE: I’ve just noticed that if I try to move manually, it appears that the what I thought was positive movement is the opposite, and vice versa. The motors will hit the stops and vibrate and I don’t want to damage anything.