BRT Community

General Category => Discussion - EVE => Topic started by: mathan_jeeva on March 09, 2021, 07:32:55 AM

Title: How to update the screen without rewriting the whole things in FT812?
Post by: mathan_jeeva on March 09, 2021, 07:32:55 AM
My application requires multiple images always present on the screen (like home, logo, volume control, signal strength and settings) and it has totally 10 pages. Now what i have done is whenever it enter into the new page i rewrite the whole things that increase the latency of application. Is there any way to keep stationary things as it is and write only the varying or changing part in order to decrease the latency?
Title: Re: How to update the screen without rewriting the whole things in FT812?
Post by: BRT Community on March 09, 2021, 10:40:21 AM
Hi,

We have some information below on how to use the Append command to recall sections of the display list.

https://brtchip.com/wp-content/uploads/Support/Documentation/Application_Notes/ICs/EVE/AN_340_FT800_Optimising-screen-updates-with-Macro-and-Append.pdf

You can save different sets of commands in different areas of RAM_G and then recall them depending on what screen you are displaying.

There is sometimes a trade-off between recalling sections and sending the full list (especially if you use a SPI burst write which is quite efficient) depending on how much of the screen changes. If you have enough RAM_G you can have all your images loaded at the start and just display them and so each new screen can be quite efficient already. But if most of the screen is static then this Append technique should help.

Best Regards, BRT Community



Title: Re: How to update the screen without rewriting the whole things in FT812?
Post by: Rudolph on March 10, 2021, 05:07:59 PM
Hello,

my basic example code includes the use of CMD_APPEND for a static portion of the display.

https://github.com/RudolphRiedel/FT800-FT813/tree/5.x/example_projects
https://github.com/RudolphRiedel/FT800-FT813/blob/5.x/example_projects/EVE_Test_SAME51_EVE3-43G/tft.c