# Current measurement

Hi,

I am working on a project which schould measure up electricity.

I do not want to use a external module. Just the Arduino.

Does somebody has any idea how to do this ?

Best regards Steven

Hi,
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html

Can you tell us;

• AC or DC.
• How many volts?
• How much current?
• Do you want to calculate power?
• Can you please tell us your electronics, programming, Arduino, hardware experience?
• How do you want to display the information.
• What is the application,what do you need the data for?

The Arduino controllers can only measure 5V or 3.3V DC, you will need extra hardware to aquire the data you need.

Tom...

AC or DC:
AC

How many volts?:
Under 50

How much current?:
Under 21

Do you want to calculate power?:
Yes

I am software programmer and I know how to code, I own much electronic, I have an Arduino UNO and I know the basics of electronics.

How do you want to display the information?:
I will put it on an LCD display (I know how to do that).

What is the application,what do you need the data for?:
It is a school project in which, I help my teacher he is a bit older and he doesn't know the Arduino. A wind mill will generate electricity and the Arduino should measure the power and display it on the LCD.

With the Arduino alone, you can measure only DC voltage in the range 0-5V.

Add a resistor and measure the voltage across it to get DC current.

Steven2105:
How much current?:
Under 21

Amps, that is?

Steven2105:
I do not want to use a external module. Just the Arduino.

If that's a firm requirement then you can stop now. Not going to happen. You're going to need external hardware for this project (and ready made external modules make it a lot easier).

Steven2105:
A wind mill will generate electricity and the Arduino should measure the power and display it on the LCD.

If your windmill is simply driving a fixed resistive load, then it would be easy - just a few resistors and your Arduino could measure the AC voltage (and therefore the current) using an analog input.

or is the windmill charging some batteries or something else ?

Yours,
TonyWilk