Paul Staron

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9 years, 4 months ago.

Help needed to enhance this library?

I have been working with this library for a few weeks using a LS027B7DH01 (400x240). I have tidied the class definition code (making it easier for different targets) and added BurstSPI which nearly doubled the buffer refresh rate and produced some useful images.

Here's a demo (the display does look better than the picture) with a KL25Z prototype board clocked with a 32KHz crystal. This clock setup (3) I have recently had added to Mbed-SRC with invaluable help from Erik Olieman. The standard FRDM board works the same, but this is easier for me to develop without all the extra toys. I achieve 7 mA in run mode and 60uA in deep sleep mode (with the display active and analog in functions). The display refresh time is in the order of 90mS that gives me approximately 23 weeks running time with a 1000mAh 3.6v mobile phone battery updating every minute , if my maths is correct, but don't hold your breath, its usually wrong :) With a small solar cell it would run indefinitely (or until the battery is wasted).

/media/uploads/star297/20150717_170421.jpg

This display although should be 5v does work reliably at 3.3v with a 3MHz clock rate.

The question is, I would like to add further fonts, but this appears to be rather complicated using 'Glyphs'. I did the usual internet search but could not come with anything that would help me (I'm crap at code basically, I do hardware). Also the BitBlit buffer write function is working with 8 bits rather than single pixel bits. That's okay, possibly speeds things up, but to be able to draw lines and circles etc. I need a pixel write function.

This is in the pipeline:

http://www.prnewswire.com/news-releases/always-on-color-memory-lcd-is-ideal-graphic-display-for-wearable-products-300075961.html

With all the 'low energy' going on, Mbed needs a GOOD display capability to match.

So if anyone has any ideas (code examples) or the time to help me enhance this library?

Question relating to:

Last updated: 07 Aug 2014
This driver is meant for the monochrome LCD display (model no: LS013B4DN04) from Sharp; but it should be easily adaptable to other Sharp displays. display, eINK, LCD, Sharp

1 Answer

Wim Huiskamp
9 years, 4 months ago.

There are some other displays in the mbed component library. This one also uses eepaper and has some graphics functions: https://developer.mbed.org/users/dreschpe/code/EaEpaper/ Some merging could get you the desired functionality.

Thanks Wim, the e-paper display is quite different to drive. The GLCD character handling would be nice to use here as it very easy to produce new fonts. I'm thinking it may pay to look at the SiLabs memory LCD driver further. I did try briefly but I believe it uses DMA which is target specific for their asynchronous low energy modes. Perhaps I could look at modifying that to use BurstSPI, could end up working at much the same speed.

posted by Paul Staron 17 Jul 2015