How you directly access serially chained devices, like LEDS, shift registers, etc?


Closed Thread
Results 1 to 20 of 20

Hybrid View

  1. #1
    Join Date
    Feb 2013
    Posts
    1,150


    Did you find this post helpful? Yes | No

    Default Re: How you directly access serially chained devices, like LEDS, shift registers, etc

    Each color value is 8 bit, so it is 6912 bytes, not bits But that's ok, I'll use external EEPROM as display buffer.
    MSSP would be great, but no PBP support as far as I know - need to use ASM....

  2. #2
    Join Date
    May 2013
    Location
    australia
    Posts
    2,670


    Did you find this post helpful? Yes | No

    Default Re: How you directly access serially chained devices, like LEDS, shift registers, etc

    it would be difficult to pack rgb leds more tightly than these
    p3 64x64 p4 32x64 modules
    Name:  p4.jpg
Views: 1268
Size:  268.3 KB
    Name:  p3.jpg
Views: 1526
Size:  220.3 KB


    and they work, limited to 8 colours with pbp
    Warning I'm not a teacher

  3. #3
    Join Date
    Feb 2013
    Posts
    1,150


    Did you find this post helpful? Yes | No

    Default Re: How you directly access serially chained devices, like LEDS, shift registers, etc

    Yes, bottom ones are 3030 leds. And they're placed sparsely.
    Now check footprint of 1206 or 0805 enclosure and compare sizes

  4. #4
    Join Date
    Oct 2005
    Location
    Sweden
    Posts
    3,617


    Did you find this post helpful? Yes | No

    Default Re: How you directly access serially chained devices, like LEDS, shift registers, etc

    Quote Originally Posted by CuriousOne View Post
    Each color value is 8 bit, so it is 6912 bytes, not bits But that's ok, I'll use external EEPROM as display buffer.
    MSSP would be great, but no PBP support as far as I know - need to use ASM....
    Say what? You start the thread about efficiency and then you're going to use external memory as display buffer?

    There is zero need for any assembly code to operate the MMSP module (or the SPI module on the Q devices for that matter).

  5. #5
    Join Date
    Aug 2011
    Posts
    457


    Did you find this post helpful? Yes | No

    Default Re: How you directly access serially chained devices, like LEDS, shift registers, etc

    If you just need more RAM for a display buffer there are much faster devices than an external EEPROM, like the 23LC512 serial SPI SRAM.
    Also, since SHIFTOUT runs at approx 50KHz, you could even write your own dedicated version that would be MUCH faster than that, although using the MSSP/SPI peripheral is pretty straight forward and would easily get you into the multi-MHz range.

  6. #6
    Join Date
    Feb 2013
    Posts
    1,150


    Did you find this post helpful? Yes | No

    Default Re: How you directly access serially chained devices, like LEDS, shift registers, etc

    Where I can learn about that MSSP in PBP ?

  7. #7
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    4,166


    Did you find this post helpful? Yes | No

    Default Re: How you directly access serially chained devices, like LEDS, shift registers, etc

    On the Data Sheet of each PIC you will use. You learn the ins and outs of the sub section of the PIC and the registers that you have to manipulate directly.

    PBP had nothing to do with the MSSP/SPI section other than setting bits in the registers.

    Ioannis

  8. #8
    Join Date
    Feb 2013
    Posts
    1,150


    Did you find this post helpful? Yes | No

    Default Re: How you directly access serially chained devices, like LEDS, shift registers, etc

    Well someone above, called Henrik , said that PBP is supporting it directly, this is why I asked

  9. #9
    Join Date
    Apr 2014
    Location
    OK
    Posts
    557


    Did you find this post helpful? Yes | No

    Default Re: How you directly access serially chained devices, like LEDS, shift registers, etc

    If you go to Microchip.com and type MSSP or SPI or I2C into the Search window, then click on Application Notes in the left column, there are numerous Application Notes on how these peripherals function, and how to put them to use. Code is usually in ASM and/or C, but the concepts are outlined extremely well.

Similar Threads

  1. LCD's with Shift Registers, and LCDOUT
    By Darrel Taylor in forum PBP Extensions
    Replies: 11
    Last Post: - 3rd April 2015, 14:34
  2. Smart Star (how to use shift registers)
    By mackrackit in forum Code Examples
    Replies: 3
    Last Post: - 30th November 2008, 20:06
  3. Use the PIC 16f877 or 877A instead of shift registers.
    By tsanders in forum mel PIC BASIC Pro
    Replies: 4
    Last Post: - 27th October 2006, 17:23
  4. Shift Registers
    By shahidali55 in forum General
    Replies: 2
    Last Post: - 7th September 2006, 20:07
  5. Shift Registers For LCD Display
    By jetpr in forum mel PIC BASIC Pro
    Replies: 6
    Last Post: - 7th July 2006, 15:03

Members who have read this thread : 0

You do not have permission to view the list of names.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts