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Display N18 Red and Blue Channels Switched


#1

Hi,

I have used a Display T35 before with no problem but a new project requires a smaller screen so I’ve got a Display N18. The problem is, the red and blue channels are switched.

Is anyone else having this problem?

The images are fine and they load fine on the T35 but on the N18 blue is red and red is blue.

I wrote a small function just to switch them over but it takes around 30 seconds to do so on a 160x128 image (N18 resolution) on a Spider board, which isn’t ideal.

Does anyone have any ideas of how to fix this or if a fix is in the works?

I don’t know much about image processing but could I use the raw byte[] way of getting the bitmap data, switch the channels somewhere there and then use DrawRaw()?

Thanks for your time.


#2

May be its not an hardware issue but a pixel format issue:
RGB or BGR !?


#3

This is by design for some of the ST7735 lcd. You can open the source code for the module driver and set the value for MADCTL to 0xC0 instead of 0xC8.

Look at the datasheet for ST7735 and look for row\col addr.

HTH.