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Re: 4.41 inch ePaper Display for the rPi

From Martin Gregorie <martin@address-in-sig.invalid>
Newsgroups comp.sys.raspberry-pi
Subject Re: 4.41 inch ePaper Display for the rPi
Date 2015-06-19 23:58 +0000
Organization A noiseless patient Spider
Message-ID <mm2aak$8gf$2@dont-email.me> (permalink)
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On Fri, 19 Jun 2015 17:43:50 -0400, rickman wrote:

> This points to another short coming in the ePaper info.  What is
> different about the displays used in eReaders and the displays Pervasive
> sells?
>
Might the Kobo use a faster, more capable controller? 

I wonder how much the update speed is affected by the transfer rate. 

Off the top of my head, if you're sending every pixel down an SPI 
connection uploading changes to the controller will be relatively slow, 
but IIRC pixel flipping is a physical process, and so is also pretty 
slow. I'd guess a cheap bit-serial controller would be rate-limited by 
pixel flipping rather than the SPI transfer rate, but what do I know. A 
full refresh on that 2.7" display is taking about 30 uS to set a pixel, 
so how does that compare with normal SPI transfer rates?

Would I be wrong to expect a more complex and expensive controller, which 
might accept byte-wide uploads over some sort of parallel interface, 
could speed up the overall refresh by flipping several pixels in parallel 
or at least double buffer the uploads so it could accept uploads in 
parallel with pixel flipping.
 

-- 
martin@   | Martin Gregorie
gregorie. | Essex, UK
org       |

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Thread

Re: 4.41 inch ePaper Display for the rPi Martin Gregorie <martin@address-in-sig.invalid> - 2015-06-18 22:39 +0000
  Re: 4.41 inch ePaper Display for the rPi Martin Gregorie <martin@address-in-sig.invalid> - 2015-06-19 19:10 +0000
    Re: 4.41 inch ePaper Display for the rPi rickman <gnuarm@gmail.com> - 2015-06-19 15:34 -0400
      Re: 4.41 inch ePaper Display for the rPi Martin Gregorie <martin@address-in-sig.invalid> - 2015-06-19 20:36 +0000
        Re: 4.41 inch ePaper Display for the rPi Martin Gregorie <martin@address-in-sig.invalid> - 2015-06-19 23:22 +0000
        Re: 4.41 inch ePaper Display for the rPi Martin Gregorie <martin@address-in-sig.invalid> - 2015-06-19 23:58 +0000
          Re: 4.41 inch ePaper Display for the rPi hamilton <hamilton@nothere.com> - 2015-06-19 18:25 -0600
          Re: 4.41 inch ePaper Display for the rPi rickman <gnuarm@gmail.com> - 2015-06-19 22:44 -0400
            Re: 4.41 inch ePaper Display for the rPi rickman <gnuarm@gmail.com> - 2015-06-20 13:29 -0400
        Re: 4.41 inch ePaper Display for the rPi cl@isbd.net - 2015-07-29 10:26 +0100
          Re: 4.41 inch ePaper Display for the rPi cl@isbd.net - 2015-07-29 21:21 +0100
            Re: 4.41 inch ePaper Display for the rPi rickman <gnuarm@gmail.com> - 2015-07-29 17:18 -0400
              Re: 4.41 inch ePaper Display for the rPi cl@isbd.net - 2015-07-30 10:23 +0100
                Re: 4.41 inch ePaper Display for the rPi Rob <nomail@example.com> - 2015-07-30 11:14 +0000
                Re: 4.41 inch ePaper Display for the rPi Dom <domafp@blueyonder.co.uk> - 2015-07-30 12:55 +0100
                Re: 4.41 inch ePaper Display for the rPi cl@isbd.net - 2015-07-30 13:15 +0100
  Re: 4.41 inch ePaper Display for the rPi Theo Markettos <theom+news@chiark.greenend.org.uk> - 2015-06-19 20:27 +0100
    Re: 4.41 inch ePaper Display for the rPi rickman <gnuarm@gmail.com> - 2015-06-19 15:57 -0400
  Re: 4.41 inch ePaper Display for the rPi Martin Gregorie <martin@address-in-sig.invalid> - 2015-06-19 19:31 +0000

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