I have made a home automation Arduino project using an HC-05 Bluetooth module. I want to power my Arduino from the main AC supply. Can I use a mobile charger/adapter to power it? Or should I buy a 12v adapter, and solder it to a barrel connector that fits the Arduino input?

6 Answers 6


Yes, you can. Both options are valid.


Yes you can use any options that you have mentioned in your question. One can say your question is your answer.


Can I use a mobile charger/adapter to power it?

The answer is almost yes: I use a phone charger myself.

Two reasons that it may not work out:

  1. There are lots of unsafe, non-isolated, cheap phone chargers out there. Stay away from them. Use a brand name one that came with your phone.

  2. Try to stay away from the QC2.0 or QC3.0. they are intelligent and negotiate the output voltage on the phone, up to 9 or 12v. They are compatible with non smart load but you don't want to run the risk.


Yes you can, simply connect the 5V VCC wire directly to VCC and connect GND to GND.

If using a 12V charger, then connect VCC to Vin.


  • 1
    Or use a USB cable.
    – Gerben
    Dec 12, 2016 at 16:06

Yes you can, I tried with a sony 5V 850mA batery, it works.

I recommend you a multimeter if you haven`t had one before.


I am in the middle of this problem now and it seems the two out of three chargers I tried attempt to negotiate the voltage with my Arduino system. Those are Huawei and Meizu ones designed to be used with multiple devices of their respective brands. The multimeter reads solid 5.2V output before I flip the switch to Arduinos. Once I flip the switch the multimeter starts jumping hectically from 1.8 to 2.6v and all the LEDs on Arduinos and other components start flashing like a Christmas tree. Browning out, I assume. The adapter that works is a really cheap nameless one that I got for free in some package.

Plugging Arduinos into the battery bank and the charger into that battery bank seems to be a very stable and versatile solution that hasn't created any problems for me yet. Except that most battery banks have trouble producing over 2 amperes of current if your system needs that much.

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