Sharp Memory LCD (400*240)

[espruino-discuss2]

Posted at 2014-10-30 by DaveNI

I would like to get one of the 400*240 displays but I assume the graphics buffer will take 12KB RAM.

http://www.makerdyne.com/blog/selecting-a-microcontroller-to-use-with-memory-lcds/

I noticed that the current flip() function seems to write 1 line of pixels at a time to the display (i.e. linebuffer rather than frame buffer approach?)

http://www.espruino.com/modules/MemoryLCD.js

Could I use a smaller graphics buffer to build & send one row of text at a time? (the display would "remember" the rest of what had been previously displayed)

e.g. if I was displaying 12 rows of text the buffer would only need to be 1KB. I would write one row at a time as needed.

I would obviously need to customise the MemoryLCD module.

I don't want to purchase one of these and then discover that I can't use it because of memory limitations.

[gfwilliams]

Posted at 2014-10-30 by @gfwilliams

Hi Dave,

Yes, that'd be absolutely fine. You could do something like:

myLCD.update(function(g,yOffset) {
  g.setFontVector(100);
  g.drawString("Hello",0,yOffset);
  g.drawString("World",100,yOffset+100);
});

And then you can allocate a graphics buffer just while updating the LCD, leaving the memory free at other times.

It's just a shame those LCDs are so expensive - because they're really nice!