water level sensor using capacitors

Discussion in 'The Projects Forum' started by wheetnee, Jan 23, 2010.

  1. wheetnee

    Thread Starter New Member

    Oct 1, 2009

    i'm doing a project where i am designing a reservoir and i will build a capacitive sensor to measure the water level that will be displayed on a LCD. There will be two plates placed in the reservoir to measure capacitance.
    As the water level decreases, the capacitence will decrease, which can be used to find the water level by reading oscillations. This capacitor will be hooked up to a microcontroller. I am using a 555 timer to build the circuit. I have a question, how will I count the number of frequencies to determine how much water is remaining in the reservoir? I want to read the number of oscillations and if it changes, I know the water level is changing. The water will be dripping through a water bottle as it decreases.

    If theres any questions about the project, please PM me :)

    Thank you
  2. SgtWookie


    Jul 17, 2007
    PM's aren't the normal way of doing things around here.

    Better to ask/answer questions in the forum; that way everyone knows what's going on.

    Are you sure you want to involve a 555 timer in this?

    What is the depth of your reservoir going to be, and what will be the dimensions of your two plates? (height, width, and spacing)
  3. wheetnee

    Thread Starter New Member

    Oct 1, 2009
    yes im using a 555 timer because the microcontroller reads square waves so i dont have to use the ADC in it to convert a sine wave to a square wave.

    height: 19cm
    width: 2 cm
    spacing: 0.05cm

    I also need to reduce the noise level/interference for my project but I havent figured out what I could use to reduce noise. Op Amps? Buffers?