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TFTs / ILI9341 Reading Display RAM
« on: April 25, 2015, 08:03:07 PM »
Does anyone have an example of reading the display ram with the ILI9341 controller?
I am using command 0x2E and cannot undertstand the data I read.
For example, I set the page and column to 0.
Then, using command 2C I write a red pixel. So i write a 0x001F (I'm using 16bpp)
Then I set the page and column back to 0.
When I issue the 0x2E command and then read 2 bytes, I get 0x00FC.
The reason I need to read the display RAM is that I'm trying to create bitmaps with "transparent" background. My bitmaps will have a predefined transparent color. For every pixel I write, I would first see if it a transparent pixel. If so, I need to read the display RAM and write the value of the current
pixel.
Any help is appreciated.
I am using command 0x2E and cannot undertstand the data I read.
For example, I set the page and column to 0.
Then, using command 2C I write a red pixel. So i write a 0x001F (I'm using 16bpp)
Then I set the page and column back to 0.
When I issue the 0x2E command and then read 2 bytes, I get 0x00FC.
The reason I need to read the display RAM is that I'm trying to create bitmaps with "transparent" background. My bitmaps will have a predefined transparent color. For every pixel I write, I would first see if it a transparent pixel. If so, I need to read the display RAM and write the value of the current
pixel.
Any help is appreciated.