[BUG] Anet A6 "garbage" on LCD screen in 2.0 (works in 1.1.9)

[Uinden]

My Configurations

Unmodified configs https://github.com/MarlinFirmware/Marlin/tree/2.0.x/config/examples/Anet/A6

Bug Description

I have Anet A6 printer and I am updating from marlin 1.1.9 to 2.0 and I have LCD problem.
I upload 1.1.9 and it works fine. (I downloaded that version in August 2018)
I upload 2.0 and its unusable. It has "garbage" all over the screen and it randomly changes on each screen refresh.
Tested bugfix-2.0.x branch and unmodified configs from there, same problem.
See attached image.

*I tried to download latest "1.1.x" branch to test, but I can't compile it due to error

Both 1.1.9 and 2.0 configs have #define ANET_FULL_GRAPHICS_LCD
I checked \Marlin-1.1.9\Marlin\pins_ANET_10.h and \Marlin-2.0\Marlin\src\pins\sanguino\pins_ANET_10.h and they have same pin numbers.
So problem is somewhere else.
Any ideas where it can be?

[Vertabreak]

needs delays i use the following turn them up till the issues stops, basically it cant keep up.
#define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
#define ST7920_DELAY_1 DELAY_NS(200)
#define ST7920_DELAY_2 DELAY_NS(200)
#define ST7920_DELAY_3 DELAY_NS(200)

[Uinden]

@Vertabreak
Wow, it helped.
Thank you!
I commented #define ANET_FULL_GRAPHICS_LCD and replaced //#define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
To

#define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
#define ST7920_DELAY_1 DELAY_NS(150)
#define ST7920_DELAY_2 DELAY_NS(150)
#define ST7920_DELAY_3 DELAY_NS(150)

And now I have working screen. (100ns still had problem so I used 150ns)

If someone will change configs for Anet A6 in this repo, please also uncomment speaker. It has been disabled since 1.1.9 and Anet A6 has speaker. I use

#define SPEAKER
#define LCD_FEEDBACK_FREQUENCY_DURATION_MS 40
#define LCD_FEEDBACK_FREQUENCY_HZ 200

And it brings back menu beeps and plays G-code music without any problem.

[Vertabreak]

i can PR that.

[Uinden]

@Vertabreak
I'm just starting to configure everything and I think I see another problem in 2.0 config.
There is

#define Z_SAFE_HOMING

#if ENABLED(Z_SAFE_HOMING)
  #define Z_SAFE_HOMING_X_POINT ((X_BED_SIZE) / 2)    // X point for Z homing when homing all axes (G28).
  #define Z_SAFE_HOMING_Y_POINT ((Y_BED_SIZE) / 2)    // Y point for Z homing when homing all axes (G28).

  //Anet A6 with new X-Axis
  //#define Z_SAFE_HOMING_X_POINT 113    // X point for Z homing when homing all axes (G28).
  //#define Z_SAFE_HOMING_Y_POINT 112    // Y point for Z homing when homing all axes (G28).

  //Anet A6 with new X-Axis and defined X_HOME_POS -7, Y_HOME_POS -6
  //#define Z_SAFE_HOMING_X_POINT 107    // X point for Z homing when homing all axes (G28).
  //#define Z_SAFE_HOMING_Y_POINT 107    // Y point for Z homing when homing all axes (G28).

#endif

So its smashing nozzle in center of bed. Not sure why its under "safe" mark.
Maybe it got accidentally ported from delta printers or something.
After commenting it printer safely homes outside of bed.

You may want to disable it/modify it.
But I'm not sure. Maybe there is good reason to home in center of bed.

[Vertabreak]

z safe home is required for probes.

[Vertabreak]

added it to the PR.

[Vertabreak]

if you encounter other problems let me know i can add more adjustments should they be required.

[Uinden]

Configured everything I need, printed some models for testing and did not got any issues related to config.
So its solved.

[kdupke]

This helped me. I had the same mangled display when updating to 2.0.

May I propose to add the following lines around line 1945 in Configuration.h?

`
// if your display mangles the content, you might have a slow (maybe older) display. Uncomment the following might help you in this case
#define SLOW_DISPLAY

#if ENABLED(SLOW_DISPLAY)
#define ST7920_DELAY_1 DELAY_NS(150)
#define ST7920_DELAY_2 DELAY_NS(150)
#define ST7920_DELAY_3 DELAY_NS(150)
#endif`

Best regards,
kai

[italocjs]

I have experienced this for the first time in a ramps1.4, same lcd. which is extremely weird because i have burned literally dozens of boards using the same program. (bugfix 2.0.x from around may of last year) Maybe its something related to the u8glib?

Using the fix proposed (add delays) worked

[italocjs]

Nothing changed (as far as i know) related to the environment ive been using (win10, 1908 / no antivirus or stuff/ arduino 1.8.10 / u8glib 1.19.1)

[slipx06]

needs delays i use the following turn them up till the issues stops, basically it cant keep up.
#define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
#define ST7920_DELAY_1 DELAY_NS(200)
#define ST7920_DELAY_2 DELAY_NS(200)
#define ST7920_DELAY_3 DELAY_NS(200)

This worked for me. Thank you

[adam57jerome]

super merci pour toutes les infos

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