• Using a hex buffer to drive the LCD

    Sophi Kravitz01/15/2017 at 21:15 11 comments

    I hadn't looked at this project in awhile, and discovered that way back when I'd ordered some inverters and XOR gates! Free parts, just sitting there.

    So I built a quick circuit with one of the hex inverters (CD4049) to drive the glass:

    The formula for frequency is determined by R1 and C1 is F = 1 / (1.39xRxC) ... I tried with a 47k resistor and a 330k. In both cases, the glass appears dark.

    What I want though, is for the glass to be able to dim. The correct driving wave form should look like this, but in order to vary the brightness/ dimming, needs a PWM signal.

  • reference links

    Sophi Kravitz02/26/2016 at 20:00 0 comments
  • Progress images

    Sophi Kravitz02/14/2016 at 20:59 0 comments

    Signal of input (channel 2) and output (channel 1) in and out of the inverter.

    The signal is from an Arduino

    analogWrite(shutterThree, 65);