STM32H743IIT6 TouchGFX External Font Garbling for Partial Unicode Characters

[JfSDK]

For STM32H743IIT6, the external font library used in TouchGFX is stored in a USB flash drive. After power - on, it is loaded into SDRAM. When displaying text, some fonts appear garbled. The font library I added covers Unicode range from 0x4e00 to 0x4e63, with a size of 100. I generated a bin file through TouchGFX. The first 100 bytes printed after the bin file is loaded into SDRAM are shown in Figure 2, and the content of the bin file opened with a hex editor is shown in Figure 3. During code testing, among the four characters "上 (shàng), 下 (xià), 不 (bù), 与 (yǔ)", only "下" can be displayed correctly, while the other three appear garbled (like a red square. I'm sorry that it's really hard to capture a clear picture on the OLED screen). Among the four characters "一 (yī), 丁 (dīng), 丂 (kǎo), 七 (qī)", only "七" is garbled. I really can't figure out where the problem lies. In addition, previously when this board used LVGL, an external font library was also ported, but there was no such phenomenon.

[GGODA]

Hello @JfSDK ,

It seems you are using a custom board.
How did you implement TouchGFX?
What have you been able to make work so far?
Does it works if you put the font in a "regular" memory, not a USB stick?

The picture is too far from the screen and the screen is too small. It is impossible for me to see what is being displayed.
The 3 characters that are displayed wrong, do they all look the same on the display?

Regards,

[JfSDK · Accepted solution]

Thank you for your suggestion. When the font library is loaded into the internal RAM, the fonts indeed do not show garbled characters. I suspected there was a problem with my SDRAM, so I replaced it with a new one, and as a result, the garbled character issue was resolved.

[GaetanGodart]

Hello @JfSDK ,

I am glad you found a way to fix your issue.

When you said that you replaced the SDRAM, do you mean you actually changed the SDRAM chip?

Regards,

[JfSDK]

Yes, I phsically replaced it.