Created May 12, 2020 © GPL3+

Arduino Capacitance Meter

We have a cost-effective capacitance meter to measure capacitance using Arduino.

Intermediate18

Things used in this project

Hardware components

Arduino UNO

555 timer IC

IC 74HC14 Schmitt trigger gate

Resistor 1k ohm

Resistor 10k ohm

Capacitor 100 nF

Capacitor 1000 µF

Adafruit RGB Backlight LCD - 16x2

Software apps and online services

Arduino IDE

Story

About Project

555 Timer IC

555 Timer IC Based Square Wave Generator

The output signal frequency relies on R1, R2 resistors, and capacitor C1. The equation is given as,

Frequency (F) = 1/ (Time period) = 1.44/ ((R1+R2*2)*C1).

By placing the resistance and capacitance values in the equation we will see the frequency of output square wave.

Frequency (F) = 1/ (Time period) = 1.44/ (21000*C).

From the above formula, we can find out the capacitance

Capacitance C = 1.44/ (21000*F)

The Uno has a specific function pulseIn, which allows us to ascertain the positive state duration or negative state duration of a precise rectangular wave.

After connecting the unknown capacitor to the 555 timer circuit which generates a square wave output and whose frequency is instantly associated with the capacitance of the capacitor. This signal is provided to UNO through the Schmitt Trigger gate. The UNO estimates the frequency. Using this frequency we program the UNO to estimate the capacitance with the above formula.

The Internet of Things Course will give you a practical implementation of such IoT devices.

Run a program

#include <LiquidCrystal.h>

LiquidCrystal lcd(2, 3, 4, 5, 6, 7);

int32_t Htime;                    
int32_t Ltime;
float Ttime;
float frequency;
float capacitance;

void setup()
{
    pinMode(8,INPUT);            //pin 8 as signal input
    lcd.begin(16, 2);
    lcd.setCursor(0,0);
    lcd.print("capacitance =");
}
void loop()
{
    for (int i=0;i<5;i++)        //measure time duration five times
    {
        Ltime=(pulseIn(8,HIGH)+Ltime)/2;        //get average for each cycle
        Htime=(pulseIn(8,LOW)+Htime)/2;
    }

    Ttime = Htime+Ltime;
    frequency=1000000/Ttime;
    
    capacitance = (1.44*1000000000)/(20800*frequency);   //calculating the Capacitance in nF
    lcd.setCursor(0,1);
    lcd.print(capacitance);
    lcd.print(" nF   ");
    delay(500);
}

Credits

hIOTron

78 projects • 2 followers

hIOTron is an internet of things based company that offers an IoT Platform, products, IoT Solutions, and IoT Training.

Arduino Capacitance Meter

Things used in this project

Hardware components

Software apps and online services

Story

Code

Run a program

Credits

hIOTron

Comments

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Arduino Capacitance Meter

Arduino Capacitance Meter

Things used in this project

Hardware components

Software apps and online services

Story

Code

Run a program

Credits

hIOTron

Comments

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