Last week I found an small and very thin LED monitor, "HL161ABB". I thought I can use it for one of my RaspberryPis. It was LED and I has VGA port not HDMI port. It was super thin and the price was only $70.
However, I also found an interesting LCD monitor for Pi. It was Tontec 2.4inch 320x240 LCD monitor connected via GPIO. The "GPIO" part is the best part of the product. It doesn't require any additional power supply and it turned out that I can still use USB keyword and USB Wifi with no power problem. Compare to "HL161ABB", the price is too high, $45, but I got it because of the GPIO part.
I was thinking to run arcade game with the LCD attached Pi. I found a problem tho. It was utilizing CPU resource to copy the video frame buffer too much. CPU utilization was almost always at max.
The source code was very simple and straight forward; about 80lines. It reads /dev/fp0 and checks if the colors are changed and if it did, it changes the color value on the LCD. It seems like the LCD displays 16bit colors, which means it takes R5G6B5 instead of full R8G8B8.
But I was wondering if it can utilize GPU rather than CPU not only for speed up but also for saving CPU availability for other applications.
I am tempted to optimize the source code but I need to
figure out if there are better versions or if anybody have done it
already. The source code had a URL advertisement like this:
printf ("http://jwlcd-tp.taobao.com\n") ;
It turned out that it is a Chinese website. I was hoping that if they made any new version of the software but I couldn't read a thing.