Hello,

we’d like to offer the following explanations and suggestions:
1. Mismatch in RGB Bit Depth (OUTBITS Setting)
Some LCD panels, although labeled as supporting RGB888 (24-bit), may internally operate using RGB666 (18-bit). If the EVE IC’s output bit setting does not match the actual bit depth supported by the display, it can lead to color distortion or visual artifacts such as noise lines.
Suggestion:
Please verify your LCD panel’s actual color depth and ensure that the REG_OUTBITS register is configured appropriately during initialization to match the panel.

2. Avoid Using CMD_GRADIENT for Red-Sensitive Precision Areas
CMD_GRADIENT uses internal linear interpolation. In high-contrast or precision-sensitive areas—such as gradients involving red—it is prone to rounding errors that may cause visible banding or fine lines.
Suggestion:
Consider using a custom gradient image (bitmap) instead, and load it into RAM or flash to ensure consistent rendering and avoid interpolation artifacts.

3. Fine-Tune the Gradient End Color & Refresh the Cache
Using red values like 0xFF0000 (full red) can fall on edge-case transitions in RGB666 mode, leading to visual inconsistencies.
Suggestion:
Try slightly dimming the gradient end color—for example, use 0xF00000 instead of 0xFF0000—and observe whether the black line still appears.
Also, try calling CMD_CLEARCACHE() to clear the on-chip bitmap cache, which may help eliminate any residual rendering artifacts.

Best Regards,
BRT Community

Hi,

Thanks for your question,

We'll check with our R&D team on this and will let you know as soon as possible,

Best Regards, BRT Community

Hello,

On the programmers guide point, this is currently going through the final review stages and we hope to have it released shortly.

I will follow up with the R&D team for your other queries.

Best Regards,
BRT Community

Hello,

Thank you for your question.

Can I ask how you have configured the interrupts?

Would it also be possible to provide a logic analyser capture of a read of the flags register when the issue occurs?

The interrupt flags not returning as expected is curious, but it would not be considered a fault scenario on its own.

Just to clarify you would only need to perform a fault recovery if the REG_CMD_READ register reports a value of 0xFFF (indicating a fault in the co-processor). In terms of EVE and the touch engine, the current valid display list contained within RAM_DL, will be read by the touch engine for tagged items, which will then updated the REG_TOUCH_TAG register if an item has been touched accordingly. In this sense as you have noted your screen manager is out of sync with what it believes to be on the screen, what is the mechanism, that you are using to keep track of screens in your application?

Best Regards,
BRT Community

I am trying out the SD card functions now and just successfully used CMD_FSDIR.

CMD_FSDIR "only" returns a bunch of names.
How can I find out which of these names are directories?

Hi Rudolph,

One way to check is to perform a cmd_fssize.  Directories will return -1 for the size.
We'll add that as a note in the document too,

Hope that helps,

Best Regards, BRT Community

Hello,

Thank you for the update!

I'm glad to hear that adjusting the REG_AH_HCYCLE_MAX registers has helped in this instance.
Please let us know if you have any further questions.

Best Regards,
BRT Community

Hi,
Yes, RGB565 is a commonly used 16-bit image format, but it does result in some loss of color information — especially for neutral tones like grayscale.
This is because RGB565 allocates only 5 bits for red and blue, and 6 bits for green. The imbalance in bit allocation can cause color distortion, which may lead to grayscale areas appearing bluish on the display.
If you want to preserve better color fidelity, we recommend using the ASTC compression format.
You can use our EVE Asset Builder tool to convert images into ASTC format.
For example, using 8×8 ASTC compression typically provides visually good quality while producing a smaller data size than RGB565.


Best Regards, BRT Community