[fixed] issue adjusting screen contrast
  • Hi guys, I'm on the verge of completing the assembly but I have issues with the lcd (yeah I know same old problem...)

    I've been twisting the trimmer for turns and turns (for more than the 24 indicated without clicks) but I saw little improvement : at first I just had a blue screen... then white squares came in, now I can painfully distinguish parameters adjustements as I turn knobs...

    Any clues ?
  • Oh and by the way soundwise, it's GREAT :)
  • What is the voltage on the trimmer middle pin?

  • Try resoldering the Pad thats connected to GND – its easy to have a cold Joint here as the Groundplane sucks up most of the heat…..

  • Should be between 0.5V and 1V for good contrast…

  • well after a closer look, I realized two pins were left without solder...

    PROBLEM SOLVED.

    Thank you guys !

    Next step, finishing the programmer ! :)