Blank Screen BTT TFT 3.5 V3.0.1 with SKR Pro 1.2 - Questions and Help

Mostly Printed CNC - MPCNC Troubleshooting
1

Hi All,

I have been working on the MPCNC and I have an issue with the BTT TFT screen being Blank/Black screen when I use it and when I try to update the firmware. It is a BTT TFT3.5 V3.0.1, with GD32F205VCT6 and I need some guidance and help to resolve this.

I have attempted to update the firmware and it does upload but then it returns to the Blank/Black screen after 100% upload. I have provided a video to show the issue. It appears that the firmware may have a bug? This was identified in this bug but this relates to E3 version and I am unsure if it has been patched into the code base or related to this issue. I have attempted using reset.txt but it does reset the firmware. SD card formatted to fat32.

Anyone had this issue lately? Any guidance? It also helps people who may have the same issue in the future.

Now background details.

I am using a SKR Pro 1.2 with dual end stops. I have flashed using V1CNC_SkrPro_Dual_2209-2.1.1 from the sd card reader on the board. I have configured the mpcnc to operate headless using V1pi and have been able to operate the mpcnc, including homing of axis on x, y, and z. I can run gcode and do all that.

I have reformatted the SD card 512MB to FAT32 with cluster size of 4096. I have update the SKR Pro 1.2 firmware with V1CNC_SkrPro_Dual_2209-2.1.1 from the V1 site and that was successful (BIN to CUR) using the SD card.

To update the firmware for the BTT TFT3.5 I have used the CNC.TFT.Package.zip from V1 to update. I unzipped the files and copied all files onto the SD and restarted the SKR pro. This is what you see when I do this. The TFT is connected to the SKR pro via the 2 gray cables and serial cable.
The one assumption I make is that the upgrade of the firmware does select the correct bin file? In this case BIGTREE_GD_TFT35_V3.0.27.x.bin firmware. I did not alter the config.ini.

As an attempt to reset the TFT I did put a reset.txt as a single file on the SD card but it did not work. I am interested if anyone has been able to get this to work?.

I have replaced both sets of cables, 2 keyed grey ones and black serial cable. This has had no effect on the outcome.
Interestingly, if I run the SKR pro I do hear the tactile noise when I push the rotary encoder for 3 seconds and turn it right and press three times I can get the SKR pro to responded by homing the Z axis. This means that cable (serial cable) is working between the TFT and SKR pro? as I think turning it right give me the touch controls element, not marlin mode. So I think the controls of the TFT are working? but not the touch elements of the display or the display itself.

So it appears, to me, that maybe the firmware bin is not quite right? Again need some advice.

Questions.

  1. Is the process of placing all the firmware files from CNC.TFT.Package.zip (uncompressed) on the SD card the right process.
  2. Does the reset.txt (0 byte) work on the BTT TFT cards to reset the firmware when place in the root directory of the SD card
  3. Is the BIGTREE_GD_TFT35_V3.0.27.x.bin for this BTT TFT3.5 V3.0.1, with GD32F205VCT6 card
  4. Do I need to recompile from the sources a new firmware bin for the TFT
  5. Has anyone else had this problem

Again sorry for the length of the message but I hope that it provides guidance for those who follow and me.

-Phil

2

For the TFT firmware you can leave all the .bin files on the SDCard and it will just take the one it needs I believe. If the firmware updated successfully the .bin file extension will be changed so pull the card and confirm that.

If the screen stays blank when swapping to marlin mode check you haven’t got one of the grey cables the wrong way round.

3

Hi Dreyfus and all,

Thanks for the information.

I have pulled the card and I can see that it does not change the extension to the bin file. :confused:
I will try the cable swap and report back.

  • Phil
4

Hi Dreyfus and all,

Ok we have progress. I have been able to get the screen to some to life by providing 5v to the 3.5 TFT without connection to the SKR Pro 1.2. I also cleaned the 3.5 tft with an air compressor just to make user that there was no dirt/debris. When I did that it requested the new driver as it indicated that it had out of date img and requested new versions. I used CNC.TFT.Package.zip packages and it uploaded and worked properly.

OK, now the next problem.

When I use Marlin (left turn of rotary encoder) I do not get a menu.

IMG_20241202_165629
IMG_20241202_1656293000×3000 338 KB

but it does give me this screen. Now it this a cable issue? or a SKR pro 1.2 issue.

  • Phil
5

Have you also flashed the SKR Pro v1.2 with the V1E firmware?

6

Good technique.

That’s really strange. I have a number of these TFT35s, and not one has ever asked me to update it. Is it possible the display was stating it had the wrong firmware in it or some other error?

Marlin mode puts the screen in “Dumb” mode, where all the functions including drawing dots on the display are done by Marlin firmware using the two grey cables. If those are not hooked up, you will get nothing except the TFT telling you it went into MARLIN MODE.

TFT mode makes the screen a smart controller. Essentially, a full up user interface and gcode sender like a little embedded version of octoprint. TFT mode only uses the black cable.

The TFT35 display unit can be powered by either the grey cables or the black cables.

You can hook up all three, or just the grey, or just the black.

If all three are hooked up you should be able to use Marlin mode or TFT mode just by switching the TFT using the rotary encoder (press and hold in the rotary knob to get the menu).

I’d try several things.

  • put the diplay in TFT mode, hook up the black cable to the SKR. Is it functional?
  • hook up the grey cables, put the display in Marlin Mode. Is it functional?
  • If neither of these work, then carefully check where and how the cables are connected. It’s possible to mix up the grey cables, and possible to plug the black cable into the wrong port on the TFT.
7

Hi Bartman and All,

Ok, I am not sure which version is V1E? Now that I have a 3.5 TFT I can see the versions of software.

IMG_20241202_142706
IMG_20241202_1427063000×3000 395 KB

Now is that the same or different from V1E firmware?

Really appreciate the comment and feedback.

-Phil

8

Hi MakerJimm, Bartman and All,

I have been able to get the 3.5 TFT to work with the TFT Mode. To me that indicates that the serial cable (black) seems to work as expected. I can now select items etc.

In terms of Marlin Mode it relies on the two gray cables to communicate with the SKR Pro 1.2? I can select marlin mode and I get the following screen.

IMG_20241202_165629
IMG_20241202_1656293000×3000 338 KB

This shows it has entered Marlin Mode but is unable to draw the menu. I am not sure if it has gone into 12864 Mode but as there is “V1 Marlin Mode” I think that it is?

So it is either the cables or the SKR Pro 1.2 firmware. Maybe Bartman’s comment on the version of SKR Pro 1.2 V1E maybe a resolution. We will see. I change the cables over tomorrow.

Now, MakerJim I agree I have never seen hardware all of sudden start working and request firmware in this nature. It indicated that it was missing directories (font, bmp) and the driver
bin (BIGTREE_GD_TFT35_V3.0.27.bin) was out of date. As this was the first sign of life of the 3.5 TFT I did not take a photo of the screen. I just wanted it going. BTW yes 5v to screen is a fail safe method.

Again will report back and thanks for the help.

-Phil

9

I think the section labelled System and Machine shows the SKR firmware. I don’t think that is the correct firmware for your machine (I may be wrong about that, I have a Lowrider, not an MPCNC)

If you are using Dual Endstops (I’m assuming that you are), you should be using https://github.com/V1EngineeringInc/MarlinBuilder/releases/download/515/V1CNC_SkrPro_Dual_2209-2.1.1.zip

The linked GitHub page from SKR Pro - V1 Engineering Documentation has many versions of Marlin, and each version has many “Assets”, several of which are hidden. Click on the “Show All xx Assets” at the bottom of the most recent version’s asset list to see everything, and then select the SKR PRO version that has Dual, but doesn’t have LR (LowRider).