Babystepping and 12864 goes crazy

dc42

@izeman which firmware version are you using?

izeman

@dc42 said in Babystepping and 12864 goes crazy:

@izeman which firmware version are you using?

RepRapFirmware for Duet 2 WiFi/Ethernet 3.4.0beta6 (2021-11-06)

dc42

@izeman please check whether 3.4.0rc1 has the same issue. You can print several mm above the bed to avoid risk of damage. I recall doing a fix to the 12864 but I can't remember the details.

izeman

@dc42 Sure. Will do so when back home. Thanks

dc42

@izeman also, please check that the cables to the 12864 display don't go anywhere near any stepper motor wires. One possibility is that it is interference to the signals from the rotary encoder that is causing the problem.

I will also run some tests here.

EDIT: I've tested in on a simple non-extruding print job on a Duet Maestro, and babystepping is working correctly for me. The menu entry I am using is:

; babystepping
text V4 R52 C0 "Baby step "
alter V4 N521 D2

izeman

@dc42 is there a difference between:

alter C88 D2 N521
alter V4 N521 D2

Well apart from the obvious positioning I guess it shouldn't make a difference if D2 comes before or after N521 ?!

dc42

@izeman correct, it should not make a difference.

Interference from stepper motor wires seems a likely cause to me.

pkos

@dc42 That can't be it. In the case of two of my printers - ribbons going to the screens are nowhere near any steppers or any other wiring for that matter.

izeman

@pkos @dc42: I agree. I did some testing now, and as you @pkos said: Setting "M918 P2 E4" solved the issue. Somehow at least.
Yes, it now need two clicks to move the "cursor" one step further, and it needs two clicks to make the BS value change - and it changes by 2 steps btw (!!), so if you got BS step set to 0.01, the smallest value for up/down is now 0.02(!!).
BUT: It is not behaving eratically anymore. The value is controllable just fine, printing or non-printing!

I tried this with firmware from November as posted before, and I tested with RC1. Both behave exactly the same.

And as it's working with E4 I also highly doubt it to be some interference.

gloomyandy

@izeman @izeman When I was doing some testing of these displays I found it was relatively easy to end up with the rotary switch positioned "bewrween" two of the steps which seemed to result with some odd combination of the switch output that resulted in constant change of the value. I wonder if you might be seeing this?

izeman

@gloomyandy said in Babystepping and 12864 goes crazy:

@izeman @izeman When I was doing some testing of these displays I found it was relatively easy to end up with the rotary switch positioned "bewrween" two of the steps which seemed to result with some odd combination of the switch output that resulted in constant change of the value. I wonder if you might be seeing this?

I thought so too, but it's working perfectly fine for EVERYTHING else. And once you set it to E4 it works as expected as well. But of course I have no idea how the encoder and debouncing is handled by the firmware ...