Arduino Based Digital Ammeter

Ammeter is used to measure current flow through any load or device. Here in this Arduino Ammeter,
 we will explain about measuring of current by using ohm’s law. It will be quite interesting as 
well as a good application of basic science that we studied in our school days

All of us are well known of ohm’s law, It states that “the potential difference between two poles 
or terminals of an conductor is directly proportional  to the amount of current pass through the 
same conductor” for constant of proportionality we use resistance, so here it comes the equation 
of ohm’s law.

V = IR

• V = voltage across the conductor in Volt (v).
• I = current pass through the conductor in Ampere (A).
• R = resistance constant of proportionality in Ohm (Ω).

In order to find the current pass through the device we just rearrange the equation as
below, or we can calculate with ohm's law calculator.

I = V / R

So in order to find out the current, we need some data:

1. Voltage
2. Resistance

We are going to build a series resistance along with the device. As we need to find voltage
drop across the device, for that we need voltage readings before and after the voltage drop,
that is possible in the resistance because of no polarity.

Like in the above diagram, we have to find the two voltages that are flowing across the resistor. 
The difference between the voltages (V1-V2) at the two ends of resistors gives us voltage 
drop across the resistor (R) and we divide the voltage drop by the resistor value we get the 
current flow (I) through the device. That is how we can calculate the Current value passing
 through it, let’s gets into it practical implementation.

Required Components:

• Arduino Uno.
• Resistor 22Ω.
• LCD 16x2.
• LED.
• 10K pot.
• Breadboard.
• Multimeter.
• Jumper cables.

Circuit Diagram and Connections:

The schematic diagram of the Arduino Ammeter Project is follows

For example:

The value of the V1= 710, V2= 474 and R=22Ω, the difference between the voltages are 236.
We convert it into voltage by multiply with 0.00488, then we get 1.15v. So the
Voltage difference is 1.15v, by dividing it by 22 here we get the current value 0.005A.
Here we have used the low value 22ohm resistor as current sensor. This is how we can
measure the current using Arduino.

 

Arduino Code:

Complete code for arduino based ammeter to measure current, is given at the end of this article.

Arduino programming is almost same as like c programming, first we declare the header files.
The header files call the file in the storage, like for the calculation I get the voltage
values by using analogread function.

Code 

#include

LiquidCrystal lcd (7,8,9,10,11,12);

void setup() {

// put your setup code here, to run once:

Serial.begin(9600);

lcd.begin(16,2);

lcd.clear();

}

void loop() {

// put your main code here, to run repeatedly:

int voltage_value0 = analogRead(A0);

int voltage_value1 = analogRead(A1);

 int subraction_value =(voltage_value0 - voltage_value1) ;

 float temp_val = (subraction_value*0.00488);

 float current_value = (temp_val/22);

 Serial.print(current_value);

 lcd.setCursor(0,0);

 lcd.print("current value=");

 lcd.setCursor(0,1);

 lcd.print (current_value);

 lcd.print("A");

 delay(1000);


}

video

ETİKETLER;

ARDUINO UNO

ARDUINO

AMMETER

RESISTORS

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