Posted on August 11, 2016 at 13:34Hi rapid84,
STM32F4 SRAM is from 0x20000000 to 0x2002FFFF ( 192KB)
you've set your Buffer Start @ 0x2002B001
as per my previous, unless you've changed the colour format settings of emWin, it'll probably be 32bits (4 byetes) per pixel.
so the 320x240 pixel display will need 300K of memory for the buffer
actual memory mapped to the buffer will only be 0x0x2002B001 to 0x2002FFFF (which is only 20KB,... well 2 bytes under actually)
The GUI & LCD driver won't care that there isn't actually any memory where the buffer is mapped to, the GUI will just write to empty space & the display will show nothing, where there is no RAM
so, 20K @ 4 bytes per pixel is 5120 pixels, which on the raster scan of the display is only the top 21 lines of the display
that seems to fit what you're getting.
as for the colour (red vs blue)
I read something (in the emWin manual I think) that the GUI uses ABGR8888 (Alpha, Blue, Green, Red) format while the LCD driver in the stm32F4 uses ARGB8888 (Alpha, Red, Green, Blue),.. so effectively red & blue are swapped over, which is probably what's causing it.
if you want to get this to work (e.g full screen buffer), you'll need to find out how to change emWin to an 8 bit per pixel format and set & set your buffer address to 0x2001D400
That'll leave you 117K of ram for everything else, which should be OK, but you'll have to change the amount allocated to the GUI as you've currently got that at 150K
(if you're not looking to use emWin's 'memory devices' (for sprites, floating windows or the like) & just want to do basic text & line-draw etc, you should be able to set that to 20K or less.
Cheers,.. Daemy
