What arduino to buy


I am working on a project where I have two components connected to an arduino (right now I have an arduino lenardo). It works as it should and therefore I need to buy a few more to have multiple of them (around 10). There are a lot of arduinos and I'm wondering if you can help me figure out which is the smallest I might need.

  • It has to use as little power as possible (battery powered)
  • I'm using both 5V (for component 1) and 3.3V (for component 2)
  • I'm using 2 ground (one for each)
  • I'm using 5 D (digital in/outs? Is that what they are called?)
  • As small as possible

That is the first part.

The second part is that I need to buy some batteries. I have the microcontroller set to 3.3V (though I guess I am also using 5V for component 1). Not sure about what that needs to be set on... I put it in 3.3 to be safe... Anyway, I want to buy a battery for the arduino that can last at least a few days (optimally around 2 months, but not sure if that is possible).

Any suggestions as to what battery to buy? Is it possible to make the arduino use less energy most of the time? Only needs to measure with component 1 and send the data with component 2 in certain intervals, maybe every 5 minute or half hour.

Any help would be appreciated on these questions as I am not an expert but just a hobbyist

A Micro is probably going to be easiest for you. It has the same chip in it as the Leonardo.

The big Arduino boards have several voltage regulators like 5V and 3.3V to make it easy for you to do experiments. When I finalize a project, I usually use dedicated voltage converters because then I can control which one does what, for which components. The range at Pololu is really quite good.

If you really want to go battery powered, then often the best way is a 3.6V lithium battery and no voltage regulator at all. You may use a step-up regulator if you really can't get rid of the 5V component.

You might consider using a standalone Atmega 328 chip which can work quite happily at 3v or 3.6v. You can get them to work at 8MHz with very few external components. See this tutorial.

Note that a LiPo cell can reach 4.2v and would probably damage a 3.3v device. It would probably be sufficient to use a diode to drop the voltage.