Powering a Nano with EasyStepper +5V pin

Hi everyone,

Here we go; my first post... I have a few question about powering my setup. I cannot find the answer elsewhere, so I hope you all can help me.
I started a new project: the automation of my bedroom curtains. In order to do so I have the following hardware:

  • Arduino Nano, with a shield
  • EasyDriver v4.4
  • NEMA 17 Stepper Motor, Casun 42SHD0001, 12V, 0.4A
  • Power supply, adapter with 5.5mm jack, 12V 600mA
  • IR remote and receiver unit

I want to be able to open and close the curtains with the use of the IR remote. Obviously I want it to work separate from my computer (so no USB cable attached for powering the Nano). Also it would be nice if I just have one power input cable (the adapter with 5.5mm jack) going to the setup.

  • With the driver being attached to the 12V input. Is it possible to power my Nano with +5V output and ground pin from the EasyDriver (and the receiver too)?
  • Would it be better to attach both the Nano and the driver directly to the 12V power supply?
  • Would it be even better to attach the 12V directly to the driver and via a regulator or buck-converter to the Nano Vcc pin? (and if so, what voltage would be ideal for the Nano)

Other suggestions are welcome of course!

What would be best in the long run? What setup would create the least amount of heat? What setup would consume the least amount of energy?

Thanks in advance

It is always a good idea to start with the manufacturer's documentation! The EasyDriver 4.4 (NOT "EasyStepper") web page says:

5V : This is an OUTPUT pin that will provide either 5V (default) or 3.3V from the voltage regulator, at a small amount of current (say 50mA - depends on input voltage) to power a circuit that you may need powered. If you cut jumper APWR (SJ1) then you can use the 5V pin as a VCC input to the Easy Driver, powering it with your own VCC supply.

Thanks. I did in advance, but had my doubts. Just wondering whether "*to power a circuit that you may need powered." *includes a Arduino + sensor. And whether the 12V would heat up the Nano, since its at the high end of the spectrum.

50mA is barely enough current to power the Nano, let alone the Nano and a radio module. Number 3 on your list makes the most sense. A buck converter to drop the 12V to the voltage that you need for Nano and radio.

Thanks. I thought so too. What would then be the ideal input voltage for the Nano?

  • Let the buck-converter split the difference: 7V / 2 -> converts from 12V to 8,5V, connect it to the Vcc pin (that takes 6-12V) and let the Nano do the rest?
  • Or let the buck-converter do all of the work (since its very efficient) and connect it to the 5V input pin of the Nano?


5V into Nano's 5V pin.

The reason to apply 5V to the 5V pin instead of 7 plus Volts to Vin is that Vin connects to the onboard 5V regulator and that regulator is not heat sinked and as such cannot supply much current without overheating.

Thanks everyone for the input!

I will get a buck-converter for the final setup. In the meantime, I'll just use the usb to power the Nano during prototyping. There are still some functions that I would like to integrate into the script. Sleeping the Nano and smooth incremental movement with the remote. Seems like I'll have some time for it coming weeks, since the Dutch Government has announced a Corona lock-down...

I also consider starting a small blog on the project for the ones interested. But I get that this is not the place for that kind of post.

Bye for now!