[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"

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 };

Bug Timeline

could be older, only noticed it now

Expected behavior

should not give error for invalid conversion

Actual behavior

gives error for invalid conversion

Steps to Reproduce

1. inside pins_(YOUR_BOARD).h -- i.e. Marlin\src\pins\stm32f1\pins_CREALITY_V4.h
2. add #define LCD_LED_PIN EXP3_02_PIN -- or any pin
3. 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

[ellensp]

- struct { uint8_t g, r, b; } led_data[LED_NUM];
+    struct { uint32_t g, r, b; } led_data[LED_NUM];

So you want to use 4 bytes for each of R,G and B that can only be 0-255 and fits with in a single byte??

[robherc]

That error is saying you're converting from a signed 1+byte (depending on arch) type to an unsigned byte type. I don't think converting to a uint128_t would get rid of the warning anywise, as it still couldn't store -3. ...might need to find where the variable oor data was declared as a signed type to fix this.

[classicrocker883]

- struct { uint8_t g, r, b; } led_data[LED_NUM];
+    struct { uint32_t g, r, b; } led_data[LED_NUM];

So you want to use 4 bytes for each of R,G and B that can only be 0-255 and fits with in a single byte??

well no, i tried different things and that was the first which cleared the error. if it were me making the choice then definitely not, but something else.

its just an example of how to think, not what to think.

[github-actions]

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This issue has had no activity for the last 90 days.
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[thisiskeithb]

Closing since you’ve opened a PR.

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.