Ever wondered how much power, a USB device consumes? Sometimes when mobile phone battery is deeply drained, mobile will not indicate whether it is charging or not. Is there a way to check current is really flowing and charging the battery? May be you are doing a USB powered electronics project and want to check how much current it draws.

Current reading of Arduino

Well I found this nice little device(seen in the image above) from Deals Extreme which is also very cheap. It shows the current and voltage of the USB device attached. All we have to do is add this device in between.

Some uses for this are

1. Find if a USB cable is complaint(Current will remain 0A).
2. Find if USB charger adapter is complaint.
3. Check if the USB device is drawing more current.
4. Check amount of current required used by arduio or raspberry pi or other embedded project boards which you are using.
5. Show off this cool gadget in-front of friends, etc.

Note: If you want to buy one like this, you may search for USB power measurement or USB current measurement.

Voltage reading of Arduino