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Graphic LCD 128x64 Problem — Parallax Forums

Graphic LCD 128x64 Problem

CrosswindsCrosswinds Posts: 182
edited 2012-03-27 15:39 in Propeller 1
Hello Guys!


Ordered a parallel graphic LCD from sparkfun. It is 128x64, and uses the KS0108B, found the object from the obex, and tried it out.


I followed the documentation in the obex, and translated it to the schematics that came with the LCD. But i get this very flimsy output. Please see video-link:
http://www.youtube.com/watch?v=CJTES9cKAHM

I have double-checked everything, but there is some simple explanation to what im doing wrong.

you guys got any ideas?


//Daniel

Comments

  • HShankoHShanko Posts: 402
    edited 2012-03-27 12:07
    What I saw appears to be updating the screen way too often. Put a delay in the loop to slow down the images for us human eye/brains.
  • CrosswindsCrosswinds Posts: 182
    edited 2012-03-27 13:24
    HShanko wrote: »
    What I saw appears to be updating the screen way too often. Put a delay in the loop to slow down the images for us human eye/brains.


    Hello! Thanks for your input, it was a good idea, but did not work.

    This is what i get with the delay in place:

    https://www.youtube.com/watch?v=k12y2NrGXlE
  • Erik FriesenErik Friesen Posts: 1,071
    edited 2012-03-27 14:43
    Some ks0108 clones need slower updates, as the object doesn't read the ready state from the lcd. Try setting the delay in the assembly driver.
  • Erik FriesenErik Friesen Posts: 1,071
    edited 2012-03-27 14:45
    try tdelay of about 300 or so, then pull it down until it fritzes, then give a margin of safety.

    ' Pin configuration

    chs1 long |<CS1
    chs2 long |<CS2
    din long |<DI
    rwr long |<RW
    enable long |<Ena
    reset long |<rst
    outs long IOpins
    datapins long DB0_DB7 'set to byte
    db0 long DB0pin
    'program
    tdelay long 90 'this sets delay for lcd
    allbits long $FFFF_FFFF
    bit0 long |<0
    bit1 long |<1
    bit2 long |<2
    bit3 long |<3
    bit4 long |<4
    bit5 long |<5
    bit6 long |<6
    bit7 long |<7
    zero long 0
    leftbits long %00000000_00001111 'masks for character placement
    rightbits long %11110000_00000000 'in half slots
    evenbits long %11111111_11110000
    oddbits long %00001111_11111111
    smallbits long %00000000_00011111
  • CrosswindsCrosswinds Posts: 182
    edited 2012-03-27 15:39
    Hi guys!

    And thank you very much for your input Erik.


    I have found the problem, and i feel real stupid.

    I did change the DI & R/W pins from 30 & 31 to 12&13. But forgot to make them outputs.
    I feel so stupid because i did only concentrate on my wiring, i think i went through it 10 times, the datasheet did not match the pins in the file. But now everything works great, even without any delays!





    and thank you Erik for the driver, just golden work :)


    Best regards
    Daniel
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