LCD, IR Proximity and Regulator

Discussion in 'General Electronics Chat' started by Galibore, Aug 15, 2012.

  1. Galibore

    Thread Starter New Member

    May 22, 2012
    Hi Guys,

    I am trying to build my first robot. The thread with more information on it is actually on a different board here.

    With the help of this thread, I came up with this diagram:
    (Also attached)

    I found that when I have the LCD backlight on, the display flickers a lot when I have the IR sensor connected as well.

    Can someone tell me if the voltage regulator would help with the flickering? Or is it overkill and should I rather just use bypass caps?

    Hope someone can point me in the right direction.
  2. #12


    Nov 30, 2010
    Well, your grounds look correct. Maybe the correct question is: can an L7805 (not the same as a 78L05) supply a serial LCD with backlight? That part number is misleading! Everybody else uses the "L" designation as a 100 ma limit chip. The L7805 can do a whole amp (with proper heatsink).

    and, your regulator chip needs capacitors to stop it from oscillating. I don't see them on the schematic.

    I don't know. How much current does a serial LCD display use?
    How much current can a GP2Y0A21YK provide?
    How many datasheets should you provide to get a proper answer?