Need more hardware help with debugging problems.
It's awfully frustrating troubleshooting problems with the MMU2S, and it seems like the hardware could help a bit more.
For example:
If the selector cannot rotate, the screws/springs are probably too tight. This could be detected by sensing excessive drive current.
The screws and springs frequently fall out while the unit lid is open. Surely there's some way to capture them so they can't do that. Springs are particularly hard to find after they bounce on the floor.
If the filament is not moving, it's hard to see the problem. Could current sensing provide useful information? Indicators on the motor shafts might be helpful.
When you press the button to try again, there are delays and it's not clear when/if anything is happening. Some better feedback would help.
Some kind of exerciser that would load and unload filaments (not all the way to the nozzle) quickly without heat would be helpful.
Better display of the sensor state would help.
For now, blinking a pulsed code with the lights would have to do, but someday a little character display could be helpful.
It's hard to remember what the 3 buttons do, especially while you are trying to fix a problem.
Perhaps there is a good systematic procedure somewhere, that I just haven't stumbled across. Please tell me!