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Topic: Control PC power with arduino (Read 9518 times) previous topic - next topic


I relation to distinguishing between power sources I found interesting article here:


So as I can understand I can measure the voltage of the power source, assuming that USB power voltage is about 5V and I will use external power adapter producing 12V I should be able to use "SecretVoltmeter" approach to recognise which power source is currently connected ? Do you think that would work ?

You can't use SecretVoltmeter , it measure the voltage of the AVcc, which in both case all 5V.

Well, looks like this SecretVoltmeter is used in this project:
where you can test the voltage of the battery powering the arduino, from that article:
You could also use it to determine if you are connected to a power source or running from batteries.

so maybe there is some change still ?!

Yes, may be 5% to 10% of 5V.

So it looks like it's is not reliable method to test if arduino is powered from power adapter or from USB.
Thread bellow contains discussion which sums up the problem and advices to use "voltage divider" as the correct solution.



Hi, finally I accomplished my project ! :)
Big thanks to the forum users for the help !
Here is the link:
Please send me any comments and suggestion how to improve my project ! :)

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