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  1. #1

    Default Decoding serial data bytes and nibbles.

    I have a hex serial 15 byte data stream in a byte array.

    ED,1E,D2,EF,2E,D3,ED,2E,D2,EF,2E,D3,ED,1E,D2,

    It needs to be chopped up into 10 x 12 bit data blocks as below.

    ED1,ED2,EF2,ED3,ED1,ED2,EF2,ED3,ED1,ED2

    How can i do that efficiently so I end up with each 12 bit block in a word array variable. eg

    DataWord[0] = ED1
    DataWord[1] = ED2

    etc etc

    Shifting came to mind but the logic scrambled my brain. Thanks for ideas
    Last edited by retepsnikrep; - 17th January 2018 at 17:08.

  2. #2
    Join Date
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    Commerce Michigan USA
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    Default Re: Decoding serial data bytes and nibbles.

    '************************************************* ***************
    '* Name : UNTITLED.BAS *
    '* Author : David Purola *
    '* Notice : Copyright (c) 2018 Tronex Products *
    '* : All Rights Reserved *
    '* Date : 1/17/2018 *
    '* Version : 1.0 *
    '* Notes : *
    '* : *
    '************************************************* ***************
    indata var byte[15] 'assuming byte 14 is most significant
    dataword var word[10] 'assuming word 9 is most significant
    outpointer var byte

    outpointer = 0
    while outpointer < 10
    select case outpointer
    case 9
    dataword(outpointer) = (indata(14) << 4) + (indata(13) & $f0)
    case 8
    dataword(outpointer) = ((indata(13) & $0f) << 8) + indata(12)
    case 7
    dataword(outpointer) = (indata(11) << 4) + (indata(10) & $f0)
    case 6
    dataword(outpointer) = ((indata(10) & $0f) << 8) + indata(9)
    case 5
    dataword(outpointer) = (indata(8) << 4) + (indata(7) & $f0)
    case 4
    dataword(outpointer) = ((indata(7) & $0f) << 8) + indata(6)
    case 3
    dataword(outpointer) = (indata(5) << 4) + (indata(4) & $f0)
    case 2
    dataword(outpointer) = ((indata(4) & $0f) << 8) + indata(3)
    case 1
    dataword(outpointer) = (indata(2) << 4) + (indata(1) & $f0)
    case 0
    dataword(outpointer) = ((indata(1) & $0f) << 8) + indata(0)
    end select
    outpointer = outpointer + 1
    wend
    Dave Purola,
    N8NTA
    EN82fn

  3. #3
    Join Date
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    Default Re: Decoding serial data bytes and nibbles.

    'another way....
    indata var byte[15] 'assuming byte 14 is most significant
    dataword var word[10] 'assuming word 9 is most significant
    outpointer var byte
    inpointer var byte

    outpointer = 0
    while outpointer < 10
    inpointer = 0
    while inpointer < 12
    dataword.0((outpointer * 12) + inpointer) = indata.0((outpointer * 12) + inpointer)
    inpointer = inpointer + 1
    wend
    outpointer = outpointer + 1
    wend
    Last edited by Dave; - 17th January 2018 at 22:27. Reason: OOPS....
    Dave Purola,
    N8NTA
    EN82fn

  4. #4
    Join Date
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    Default Re: Decoding serial data bytes and nibbles.

    neither of daves options works for me, I might be imagining the input differently
    I have a hex serial 15 byte data stream in a byte array.
    would need 30 bytes and could be parsed using serin2 ...[hex3 dw[0],hex3 dw[1] .......

    I assume a input constructed like this,

    ie 15 binary values in this order ,
    arraywrite inbuff ,[$ED,$1E,$D2,$EF,$2E,$D3,$ED,$2E,$D2,$EF,$2E,$D3,$E D,$1E,$D2]




    this does work



    Code:
      
      Pause 500       ' LCD initialize time
        lcdout $FE,1   
        inbuff var byte[15]
        
        dataword var word[10]
        d var byte
        INPOINTER VAR BYTE
        outpointer var byte
        arraywrite inbuff ,[$ED,$1E,$D2,$EF,$2E,$D3,$ED,$2E,$D2,$EF,$2E,$D3,$ED,$1E,$D2]
        
        
        for d=0 to 4
        dataword[d*2]=inbuff[d*3]*16+inbuff[d*3+1]>>4
        dataword[d*2+1]=inbuff[d*3+2]+(inbuff[d*3+1]&$f)*256
        next 
        
        for d=0 to 4
        IF D=4 THEN
        lcdout $FE,$80+d*4,hex3 dataword[d*2]
        lcdout $FE,$c0+d*4,hex3 dataword[d*2+1]
        ELSE
        lcdout $FE,$80+d*4,hex3 dataword[d*2],","
        lcdout $FE,$c0+d*4,hex3 dataword[d*2+1],","
        ENDIF
        next
    Attached Images Attached Images  
    Last edited by richard; - 18th January 2018 at 00:16.
    This is more entertaining than Free to Air TV

  5. #5
    Join Date
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    Posts
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    Default Re: Decoding serial data bytes and nibbles.

    daves idea compiles to be 200 words shorter . I like that
    but I still can't get it going
    Last edited by richard; - 18th January 2018 at 01:11. Reason: still trying
    This is more entertaining than Free to Air TV

  6. #6
    Join Date
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    Location
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    Posts
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    Default Re: Decoding serial data bytes and nibbles.

    to make I work
    the input array needs its bit order endianness reversed then the result needs the same treatment
    which defeats any gain


    Code:
        for d=0 to 14
        inbuff[d]= inbuff[d] rev 8
        next
    
    
    
     outpointer = 0
     while outpointer < 10
     inpointer = outpointer*12
     d=0
     while d<12
     dataword.0((outpointer * 16) + d) = inbuff.0(d + inpointer)
     d=d+1
     wend
     dataword[outpointer]=dataword[outpointer] rev 12
     outpointer= outpointer + 1
     wend
    This is more entertaining than Free to Air TV

  7. #7

    Default Re: Decoding serial data bytes and nibbles.

    Thanks to all your help.

    I ended up using this bit but it's still boggling my mind a bit as to how it actually works.

    Code:
       for d=0 to 4
        dataword[d*2]=inbuff[d*3]*16+inbuff[d*3+1]>>4
        dataword[d*2+1]=inbuff[d*3+2]+(inbuff[d*3+1]&$f)*256
        next

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