# Arduino Voltmeter :)

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## Introduction: Arduino Voltmeter :)

Hey guys again :)

In this project i have tried to explain how to make Voltmeter with an Arduino....

Firstly , as you can see from the Voltage Divider Circuit, How we can measure to voltage on the R2 resistor?
Well, it is very simple: Using Voltage division formula , DCIN*R2/(R1+R2). which give us the voltage on the R2 resistor.

Based on this formula we can built a Voltmeter with an Arduino...Using 10k and 1k for the resistors so that i get 1/11 ratio. Which means We can multiply 5v with 11 and in theoretically we will be able to measure up to 55 Volt. However, do not try to measure above the 25-30 Volt. I have never measured but i am not sure arduino can work properly with that much Volt. So, it may cause damge your arduino... SAFETY FIRST :)

Secondly,we are connecting this output(R2 VOLTAGE) to the A0 pin.Which means we will get 0-1023 values. When the voltage is 0 our value will eb 0, when the voltage is 5 our value will be 1023. So we need to multiply our value with 5 and divide it with 1023. Thats why we have used that formule inside the code : vout = (value * 5) / 1024.0

Also for the first time i have created FUNCTION in my codes.I have never done this before in my projects,but this time instead of copy-paste my code into most part of my code i just created function and just called it as function whenever i need it :)

And lastly , in order to calculate percentage of battery, i have divided my project in 4 parts. First for 1.5v , Second for 3v , Third for 9v and ,Last one for the Free measure .

If you still don't know how to create custom chars and animations on the LCD please visit here :Click Here....

Required Materials:

x1 Arduino UNO

x1 16x2 LCD( in order to visualise my project)

x1 keypad(in order to calculate percentage of each batteries such as 1.5v, 3v, 9v...)

x1 10k Ohm resistor

x1 1k Ohm resistor

x1 Potentiometer (10k)

Codes,library and Circuit diagram has been uploaded here,but you can reach them also from github(In the codes you will see Turkish words,don't be afraid of them :) i have translated it almost every part of my codes for you and wrote it just behind the codes....) CLICK...

If you guys like my projects and if they help, please LIKE my videos so that i understand they are helpful and keep going for new projects :)