Ender 3 Pro - RRF 2.04 - can't get 12864 LCD to work

[dc42]

Could it just be that the contrast needs to be adjusted?

[ccluck]

@dc42 , this is the version that doesn't have a trim pot, at least that I can see. The display works perfectly if I plug it into the old Creality board.

There is a very little hole in the back of the board that may be an access hole for some adjustment - I'll take a look now

also, in case you missed it in an earlier post, I've got two recently purchased Maestros doing the same thing - with both the Ender LCD and a RepRap Discount Smart Controller from an old Tevo Tarantula

[ccluck]

@ccluck well, my memory was faulty - there is no hole on the back at all, so no possibility of any adjustments.

I suppose the next step is to try the one-wire-at-a-time hookup method, pulling from the EXP3 port on the LCD and breaking out the wires to EXP1 and EXP2 on the Maestro. Not sure I have connectors at hand for this and I'm not at all optimistic about the outcome.

It isn't a big deal, really. I just thought it would be nice to turn a knob to babystep instead of using the ipad. I would like to solve the mystery though.

[dc42]

Are you supplying VIN power to the Maestro? If you are supplying USB power only then the 5V supply will be low, which has a substantial effect on the contrast.

[PaulHew]

In my experience, I had no problems with the Ender3 Pro display. I was using a paneldue but moved this to my RailCore.
Plugged it in as per @Phaedrux instructions, one cable I remember came with the Panel Due and one which came with the Creality BLTouch full kit.

If you have a spare ribbon cable try swapping the multi coloured one.
Also IIRC, there is an arrow on each of the connectors which indicates Pin1.
Make sure that trace cable is the same on both ends and points to the arrow.

In this case the red trace

Paul

[ccluck]

Paul - I have two ribbon cables exactly like the one you pictured and confirmed that the index trace is at the arrow, both ends.

David - the Ender machine has the Maestro connected to the OEM 24VDC power supply, there isn't anything plugged into the USB port. The Monoprice machine has its Maestro running from a 25A 13.8VDC power supply left over from ham radio days, also nothing in USB port

[ccluck]

I've found a discrepancy between the known setup and what I have here - the guide shows the setup for a board labeled "128647W-10" while mine is labeled "ENH12864Z-1"

They are similar in that they both have the three big black dots on the back, but are actually very different in the arrangement of pretty much all the other components

Y'all reckon this is the issue ? My LCD is some weird variant that just isn't going to work with the proven pin connections ?

but that doesn't explain why the other LCD, the RepRap one, doesn't work either

[dc42]

It shouldn't make any difference; but what happens if you leave out the F2000000 parameter on the M918 command in config.g? Or use a lower value such as F1000000 ?

When using the RepRapDiscount display, you do not need to reverse the connectors, assuming it is a faithful clone of the original design.

[ccluck]

removed the G4 line above M918 and deleted the F parameter.

The RepRap LCD looks legit to me - labeled "RepRap Discount Smart Controller - www.bigtree-tech"

[DIY-O-Sphere]

@ccluck
I had similar problems with a "RepRapDiscount Full Graphic Smart Controller" only displaying blocks.
Can you also remove the E parameter for testing.
That code worked with RRF2:
; Display
M918 P1 ; 128x64 Reprap Display

[dc42]

@ccluck, the LCD in that picture is the wrong sort. It's a 20 x 4 text LCD, not a 128 x 64 graphic LCD.

[ccluck]

Thanks David - I guess that's a non-starter then. I truly didn't know that. I think I'll order a 128X64 RepRap LCD off Amazon for $12USD. Worth the investment just to see if these two particular Maestros really will drive a display.

[Phaedrux]

So you weren't using the display that came with the Ender?

[ccluck]

@Phaedrux , yes, I was making every attempt to get the OEM Ender display running, without success. I only just threw the other one into the mix to see if it might work. Wasn't aware that it is an entirely different sort of device. I just pulled it out of a box of Tevo Tarantula that was given to me, read the label that says RepRap...... so I tried it.

To reiterate, my stock Ender 3 Pro LCD doesn't work with ANY of the suggestions proffered thus far. I've meticulously followed your guide, been back over it several times, tried everything suggested in this thread - all to no avail.

I'll buy a RepRap display off Amazon to see what's up - I'll be doubly sure it is a 12864 device. If that doesn't work, then OK, its an ineffable mystery and I'll just continue using an old phone when I need to stand right in front of the machine for babystepping.

[Phaedrux]

@ccluck how do the pins on the maestro LCD connector look?

[ccluck]

they look OK to me, the connectors are snug when they go on, not loose or wiggly

[ccluck]

@ccluck 

This is the back side of the LCD board I'm trying to connect - not same as the one in the Duet_Ender3 guide, but it works fine with a Creality 1.14 board and the upgraded Creality "silent" 1.15 board connected to their single ten-pin (EXP1) connectors ( they don't have EXP2 or EXP3 ) Like I said earlier, I have two Maestros here, each easily accessible, so I've tried both with no luck. I must be missing some fundamental key to the puzzle, like it needs some other key besides the M918 enablement.

[Phaedrux]

I'm wondering if the pinout on that LCD version is just different.

[ccluck]

@Phaedrux , me too, but further investigations must wait. GF has persuaded me to take her out dancing at the biker bar out in the woods .... it'll be a nice break from the print room.

[ccluck]

For all interested parties, I have news - the $12 RepRap Discount Full Graphic Smart Controller arrived today, and instantly worked as it should, no set up or monkey business required to get it going. Yahoo !

So there it is - there is at least one Ender OEM LCD variant out there that will not readily play with the Maestro.

Thanks to all who contributed advice and comments - I appreciate your time and attention to this little issue.