Flowcode Support Board

Hi team!

As you know I use the ILI9488, ILI9341 and the ST7796 in lot of my project. I discover that the ILI9488 when using Highspeed that the prescaler max can be set to 60 mhz. Compared to the other above display can run easily up to 80 mhz, is there a specific reason for that?
The same display, Ili9488 is faster in FC9.. I am avare of the pixel queue, set to max 320 if over the display flicker.

The other display work fine. The pixel queue, what is the nomally value and max. recommened, please?

Thank´s in advance

Br jorgen

Hello,

If you're just doing clears then v9 and v10 should be comparable, if not maybe I've broken something what sort of difference are you getting? If you instead do things like print rectangle or straight lines then you should find that these are significantly slower in v9 then in v10.

As for the max SPI speed, do you mean 60 is the highest you can select or abover 60 it stops working? Might be worth checking on a scope. Looking at the specs sheet for the ILI9488 it is rated for 15 to 20MHz with reports of getting it up to 40 MHz if you have nice short traces. I've had it working reliably at 32Mhz but any faster and it stops working. The ESP can be a bit tricky with SPI speeds and even though you set it at a fast rate it will only run at the rate it thinks it can acheive and have it work.

As for the fast pixel queue size this largely depends on how much RAM you can devote to the display. A full row of pixels is normally enough to provide a significant speed boost. Even 40 pixels is good and this is the size used for the ILI9488 clear function in v9. On the ESP32 the time is taken setting up the SPI transfer and the transfer itself happens very fast so the more you can put into a single transfer the faster the display will run.

Hi Ben!

Thank you for the explanaiton.

I thought that all the Ili9341, ili8488 and St7796 was in family or some similar, therefor I wonder the ILI9488 max speed is 60 mhz when the other can 80mhz. Above 60mhz ili9488 still work, but is black, white and striped. When the datasheet for the ili9488 says the maxspeed is 20 mhz, then it might be nice it can handle 60 mhz mhz in FC in HSPI.

It's ignorance from me, sorry, you're doing a good job, thank´s

Br Jorgen