topic Re: K70 Color Keying in Kinetis Microcontrollers

K70 Color Keying

ant1882 — Mon, 14 Jul 2014 09:15:26 GMT

Hello

I am trying to use the color keying feature of the K70 LCDC without success. I am using the tower system, I can display things on the LCD (our own) without any issues, using the graphics window and background.

What I have is a graphics window of 100 lines with a group of red lines in the middle, from my understanding if I enable color keying correctly these red lines should become transparent... is this correct? If so then below is the code I am using to enable color keying:

// set LCD graphic window control

LCDC_LGWCR =

LCDC_LGWCR_GWAV(0x9f) | // alpha-transparent value (0xFF is opaque)

LCDC_LGWCR_GWE_MASK |

LCDC_LGWCR_GWCKE_MASK | // Colour Keying enable

LCDC_LGWCR_GWCKR(0x3f) | // Red colour keying

LCDC_LGWCR_GWCKG(0) |

LCDC_LGWCR_GWCKB(0);

If anybody has used color keying successfully I would appreciate any help or ideas as to why mine doesn't. Apologies if I have missed any information that may help.

Best Regards

Anthony

Re: K70 Color Keying

apanecatl — Thu, 17 Jul 2014 20:50:16 GMT

When you enable color keying all the selected color component in the graphic window will become transparent, not only those pixels with a 100% red color component.

Re: K70 Color Keying

apanecatl — Thu, 17 Jul 2014 21:07:54 GMT

If you want to remove the Red component and display the Green and Blue components you would have to set the color keying as follows:

Red color keying Green color keying Blue color keying

LCDC_LGWCR_GWCKR(0x00) | LCDC_LGWCR_GWCKG(0xFF) | LCDC_LGWCR_GWCKB(0xFF);

a 0x00 in any of the color keying fields will render it completely transparent whilst a 0xFF value will render it completely visible.

Re: K70 Color Keying

ant1882 — Fri, 18 Jul 2014 07:04:51 GMT

Thanks for the explanation.

Unfortunately it still doesn't work for me, so I must be missing something else. I shall have another look when I get chance.