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Decrease backlight consommation

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  • Decrease backlight consommation

    Hello
    To reduce the backlite consommation when display module is powered by batterry, is it possible to switch on and off the backligth by pin-set command as fast as possible to create a PWM signal on LEDs Backlight?

    Rdgs
    Vincent

  • #2


    You could certainly try, if that's the effect you are after, not sure it wouldn't appear to flicker though.

    Of course you couldn't sleep the display though, so it would consume quite a bit more than backlight off and sleep.

    Which display are you talking about? The uLCD-43 does have backlight control.
    Mark

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    • #3


      Hi,

      The module is an uLCD-28PT-GFX.
      I will try the sys_SetTimer instruction with something like 10ms timer event to do an "on" and "off" interval sequence on the backlight.This should give me a 50% duty cycle on the backlight and decreasing the power consommation. If I am luky I hope there will be no unconfortable fliker.

      Rdgs
      Vincent

      Comment


      • #4


        Hi,

        My idea was use a 1ms BACKLITE ON and 1ms BACKLITE OFF to save power up to 50mA (i not forget processor supply and others).
        For this I used a function which switch on and switch off the backlite every 1ms with sthe ys_SetTimerEvent() function for background running.
        and the problem I found is that Timer Event is not accurate. I have an unconfortable fliker of around 20ms. This is because I used a loop in my main program to do acquisition from a sensor.
        So it seems a bad way for backlite intensity variation
        Vincent

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        • #5


          Yes, that would happen if it takes 'a while' to get information from your sensor.

          If you have pauses in your sensor acquision, perhaps try to reorganised the code so they are not needed (Use another timer?)
          Mark

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          • #6


            Using 3.2PTU, 2.1.1 pin_Set(mode,pin);

            Is there coding to turn-off the backlite and back on again?

            I find no backlight control pin on the H1,H2, or H3.

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            • #7


              On a 32PTU you use gfx_Contrast() 0 and non-zero to turn the backlight on and off
              Mark

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