Which Arduino for nRF24L01+ (3.3V issue)

Hello everyone!
I've been planing a little project for some time now and I've come to a point where i need your help.
I am planning to have Arduino Uno + Ethernet Shield + nRF24L01+ transiever as control point (sends out commands, hosts a website) and little arduino+transiever systems around the house.
I understand that there is no problem with connecting Arduino UNO with nRF24L01+, so there is no problem with that.
I want to make a node by connecting Arduino NANO and nRF24L01+ which could be inserted everywhere necessary. For example, behind the light switch, so it would receive a command from Arduino UNO, then it would execute the comand and send back the state of the light switch.
But i read that if Arduino Nano is powered by external power source then there is no power to 3.3V pin? And even if there was a possibility to power NANO with USB, the 3.3V pin will only provide 50mA which is barely sufficient to operate nRF24L01+?

Maybe there is an arduino board which is more suitable for my goal or it is possible to make it work with Arduino Nano too?

Oh, and here is an approximate picture of the nodes i want to make.


Long, long time ago, there was a version of the Nano that used the 3.3V of the usb chip and that chip was not powered when the usb was not connected. That has changed with newer versions. You can always use the 3.3V.

There are more errors on the Arduino site, and I found it impossible to get those corrected =(

The 50mA is however a problem. Perhaps the Pro Mini has just enough power to do that. The Pro Mini has a real voltage regulator for the 3.3V, but it has no usb connection.

What about the Micro ? (The miniature version of the Leonard).

You can use a 5V Nano with an nRF24L01+ without any problems, as long as you remember to power the RF24 from the 3.3V pin. However, the range of these un-amplified transceivers is relatively poor in my experience and I wouldn't expect them to communicate across a typical house, so check the range you can get before you commit to this solution. There are some Arduino clones with integral WiFi which cost more but might be a more reliable basis for your project. Also consider buying an X10 solution before you commit to making your own equivalent.

Hey, thanks for the reply!
Oh, now i get it. On the Arduino site it says one thing, but people who are using Arduino Nano for their projects say that everything is working fine with external power source, so that got me confused.

I guess Pro Mini would be OK, but have to do a little research first. Probably would buy something like this then http://www.ebay.com/itm/Pro-Mini-atmega328-5V-16M-Arduino-Compatible-CP2102-USB-2-0-to-UART-TTL-module-/310941830171?pt=LH_DefaultDomain_0&hash=item486593cc1b But then again on the Arduino site Pro mini looks different than on that ebay listing. :roll_eyes:

Yes, at first i was looking at Arduino Micro, but couldn't exactly find it on ebay, so decided to go with Nano.. And I think there are more that one Micro versions out there?
I guess this is Leonardo Micro

Than there is this

And this

There are so many Micro boards, I'm confused :smiley: ...
But yeah, those Pro mini would be better than Nano if you look at the price range...
Edit: Just found out that Pro mini DC Current per I/O Pin is 40mA. That means it's lower than Nanos 50mA. So it doesn't mean that Nano is better than Pro Mini for nRF24?

Thanks for the tip PeterH. And what about the nRF24L01+ version with Transmit Power amplifier and Receive Preamplifier? I guess that range is better but is it worth it ?(http://www.ebay.com/itm/NRF24L01-PA-LNA-SMA-Antenna-Wireless-Transceiver-communication-module-2-4G-1100m-/310651702557?pt=LH_DefaultDomain_0&hash=item485448cd1d)

I also checked out the X10 solution, but if i understood correctly, there will be a transceiver(big ugly white box) in the outlet you want to control to make it work? And is it even possible to write a code for a sensor and upload it to the X10 system to brighten the hallway when you are going to bathroom in the middle of the night?


And what about the nRF24L01+ version with Transmit Power amplifier and Receive Preamplifier? I guess that range is better but is it worth it ?(http://www.ebay.com/itm/NRF24L01-PA-LNA-SMA-Antenna-Wireless-Transceiver-communication-module-2-4G-1100m-/310651702557?pt=LH_DefaultDomain_0&hash=item485448cd1d)

I haven't used them, but comments from others confirms the range is massively increased and would certainly do everything you need. However, the power requirements and physical size are obviously both increased too which will make it harder to package.

However, the power requirements and physical size are obviously both increased too which will make it harder to package.

Well, as it says in the specification to operate this amplified module you will need to provide 3-3.6V (recommended 3.3V). The same as the non-amplified module, but Emission mode current(peak) is 115 mA and Receive Mode Current(peak) is 45 mA. So is it possible to power this amplified module with Arduino Mini Pro or Arduino Uno as their DC Current per I/O Pin for Mini Pro is only 40 mA and 50 mA for Uno?
Here is the link where I got the nRF24l01 amplifidied modules specifications.