[BUG] LED control in encoder.cpp - invalid narrowing conversion

[classicrocker883]

Did you test the latest bugfix-2.1.x code?

Yes, and the problem still exists.

Bug Description

invalid narrowing conversion from "int" to "unsigned char"

It is apparent that R and G are swapped, generally it should follow RGB, not GRB, and also you see G (or g) shifts 16 bits, not 8 which it is supposed to, as for R (or r) it shifts 8. so basically, these are backwards. I was messing around and saw LED_Action() commented out and wondered why

      #if PIN_EXISTS(LCD_LED)
        //LED_Action();
      #endif

so I enabled that pin, and stumbled upon this error.

one possible fix is

-    struct { uint8_t g, r, b; } led_data[LED_NUM];
     for (uint8_t i = 0; i < LED_NUM; i++) {
       switch (RGB_Scale) {
         case RGB_SCALE_R10_G7_B5:
-           led_data[i] = { luminance * 7/10, luminance * 10/10, luminance * 5/10 };

+    struct { uint32_t g, r, b; } led_data[LED_NUM];
     for (uint8_t i = 0; i < LED_NUM; i++) {
       switch (RGB_Scale) {
         case RGB_SCALE_R10_G7_B5:
+          led_data[i] = { luminance * (u_int)7/10, luminance * (u_int)10/10, luminance * (u_int)5/10 };

---

I would also like to point out this code:

  // LED initialization
  void LED_Configuration() {
    SET_OUTPUT(LCD_LED_PIN);
  }

It is unused, so chime in if anyone has experience in this area so I can test this properly

Bug Timeline

opened #26552 but the issue was closed without the PR I created being merged

Expected behavior

should not give error for invalid conversion

Actual behavior

gives error for invalid conversion

Steps to Reproduce

1. make sure you define HAS_DWIN_E3V2 -- i.e. DWIN_LCD_PROUI
2. inside pins_(YOUR_BOARD).h -- i.e. Marlin\src\pins\stm32f1\pins_CREALITY_V4.h
3. add #define LCD_LED_PIN EXP3_02_PIN -- or any pin
4. go to encoder.cpp and you will see the error

Version of Marlin Firmware

bugfix-2.1.x

Printer model

Aquila

Electronics

No response

LCD/Controller

No response

Other add-ons

No response

Bed Leveling

None

Your Slicer

None

Host Software

None

Don't forget to include

• A ZIP file containing your Configuration.h and Configuration_adv.h.

Additional information & file uploads

No response

I may be able to test this at some point using #26946