Plugging in a 12V/10A solar panel to the barrel connector on a 101

Should I just do it?

There's two possible responses, I know:

  1. Sure, you'd be fine

  2. You really don't know the first thing about electronics, do you? (which would be fair).

I'm pretty good with the software side of things, obviously still a newb on the hardware side.

Thanks for any response at all!

NO is the short answer

There are a number of reasons and the first is the voltage.
It is getting close to the top limit and if you read through posts in the forums you will see people who have popped thier boards with 12 Volts.

Amps. Its not volts that kill people its the Amps. Again you need to be lower with sensitive electronics and read the specs for the board.

If this is a 12 Volt solar panel meant for camping and auto type use you may even find that it goes above 12 volts. Or it swings with the light available.

I would suggest some basic checks first and then some form of smoothing if required and a voltage dropper of some description.

if it has a cigarette lighter type outlet often found in cars then a USB adapter that goes in there might be suitable to lower the voltage but that might be subject to voltage drops with the light so between that and the panel some form of storage eg. a 12 Volt battery. That would also help a little to regulate the supply.

There are more technical reasons than my simple explanations but I hope these help for now.

OK thank you @Ballscrewbob for curtailing my impatience!

I did suspect the answer would be along those lines, and seems I have quite a bit of reading to do. Seems I’m some way off getting my project figured out but you at least have helped with a “temperature reading” on just how far I need to go with my education before trying to step further along.

Many thanks!


Ballscrewbob's short answer is correct in your case. If you are not all that familiar with the hardware side of electronics, it would be best to get help as you develop your project. I would like to offer some additional information on a few of Bob's points.

  • The Arduino 101 is rated for a recommended input voltage of 7 to 12 volts. It is actually rated from 7 to 20 volts for damage-free operation. A 12 volt input to the barrel jack on the 101 is not going to fry the Arduino if there are no other external components attached.

The problem with higher voltages lies with the on-board voltage regulation on the Arduino boards. It is not made to allow significant draws of current over what the Arduino 101 Curie processor needs. Input voltages over 12 volts mean excess heat will be generated inside the regulator. If you are using either of the 3.3 volt or 5 volt connections on the 101 to power other components in your project, you could overheat and fry the Arduino 101's on-board voltage regulator.

You can safely use 12 volt inputs so long as any additional circuitry either uses only 12 volts from the Vin pin or has it's own voltage regulator which is designed to get to any 3.3v or 5v your external components may need. (I have a design that uses 12v nominal input without problems. My DC input to the power jack actually gets anywhere between 11 volts and 14.5 volts in use. I DO NOT power any of my external components in the project from the Arduino's 3.3v or 5v outputs. All of my external components derive their power from the ~12v Vin.)

As Bob warns, though, make very sure that your input voltage is never going to go above about 15 volts to allow for a safety margin. Even short excursions to over 20v may damage the Arduino.

  • You do not need to worry about the amperage of the power supply when the only consideration is the preservation of your Arduino board. The Arduino will only pull the current needed to run. Excess current will never be "forced" into a circuit due to the capability of the power source. Even though your solar panel may be rated to supply "up to" 10 amps, the Arduino alone will not draw any more than it needs (usually in the range of 0.5 to 1.5 amps). (Again, my ~12v project is run from a large battery rated as capable of supplying over 500 amps. The project only pulls about 3 amps maximum from the battery.)

However, take Bob's caution to heart in terms of wiring errors in your project. During development of your Arduino based project, you could inadvertently create a short circuit while attaching things to your board. Such a short circuit can allow as much current as the power source can muster to flow. Large currents can mean near instantaneous massive heat release. (Read that to mean your Arduino and project could literally melt / burst into flames / burn you.) I would recommend developing your project using a 12 volt, 1.5 - 2.0 amp wall wart type of supply. Once the project is finished and working, you can safely power it from the solar panel with more capacity than you need.

So, with all those caveats aside, my answers to your questions would be:

  1. It's possible when proper care is taken to limit external component power draw from the 3.3v or 5v pins of the Arduino.

  2. You should get (preferably local) help with the electronic hardware portions of your project.

Best Regards,

@ jdupton

Thanks for the more technical aspect its always good to get more POV.