Arduino Pro Mini 5V or 3.3V?

Projects General Guidance
1

Hello,
im planing on building some sort of wireless home control. Therefore i ordered a few of these NRF24L01+ Modules (http://www.ebay.de/itm/SainSmart-New-Arduino-NRF24L01-Wireless-Transceiver-Module-2-4GHz-100m-range-/320951854865?pt=Bauteile&hash=item4aba38a711). The specifications say "1.9V-3.3V Vcc input".
I want to use them with a small Arduino Board, so i thought about the Arduino Pro Mini, on the product page it says that the board is available in a 5V and 3.3V Version. All other Arduinos (Uno, Mega, Nano) are 5V, right? So what Board should i use?
If i bought the Arduino Pro Mini 5V, how could i use the Wireless Module? Or is it better to use the Pro Mini 3.3? Is there any disadvantage with the 3.3V Board?

But still, how can i use the Wireless module with my other 5V Arduinos?

Thanks a lot
Dennis

2

(noob here, FYI) lol..

does it require +3.3v for LOGIC?...

if so.. I would just go with the +3.3v Pro Mini's..

otherwise you will have to fiddle with level shifter or voltage divider.

3

The input signals of that module are 5V tolerant.
But the power has to be 3.3V.

So either use the Pro Mini at 3.3V or use a 5V Arduino and power the module with the 3.3V pin.

This is some code for it, Arduino Playground - Nrf24L01

4

ah ok, so it's ok when the logic connections are 5V, good to know.

Is there any disadvantage with using the 3.3V Version?
And the 4V Mini Pro doesn't have a 3.3V Pin, right? So the VCC Pin is either 5V or 3.3 depending on the Board?

5

The Vcc is either 3.3V or 5V. The 3.3V is sometimes called 3V, but it is 3.3V.

The 3.3V Arduino is 8MHz. To run at 16MHz, 5V needed.
But that is not a problem for most applications.

The 3.3V Mini Pro also needs a serial adapter for 3.3V to upload the sketch.

6

ah ok, so mabye the easiest way for me still is to use a 5V Board, just because all my other boards are 5V too, which makes testing easier.
So i dont have to to anything with the logics? But i would have to reduce the 5V to 3.3V for the power. Is that easy?

7

and may i add a question regarding the USB Connection. To use it i need an FTDI Board, right? So sth. like this

http://www.watterott.com/de/FTDI-Breakout-Reloaded-V11

But when i look at those boards, they all have a 6-PIN Header [DTR,RX,TX,VCC,CTS,GND], but when i look at pictures of MiniPro Boards they dont have the same PIN's:

e.g.
http://www.ebay.de/itm/New-Version-Pro-Mini-Atmega328P-5V-16MHz-For-Arduino-Compatible-/170968687934?pt=LH_DefaultDomain_0&hash=item27ce87253e
[DTR,RX,TX,VCC,GND,GND]

[??,TX,RX,VCC,GND,??]

I'm a bit confused about that???? :wink:

8

Most Arduino boards have a 3.3V pin. That is an output voltage for modules and sensors. So you can use that.

The Mini Pro 5V does not have such a onboard 3.3V.
So if you use the Mini Pro 5V, you have to make 3.3V yourself with a voltage regulator.

The Mini Pro also doesn't have a usb-to-serial adapter on board.
So you have to buy one.

The links are okay, you can use those. Some Pro Mini 5V 16MHz are even cheaper than that. I just bought one myself for less than 5 euros.
You need RX (or RXD), TX (or TXD) and DTR. The DTR signal is used to reset the Arduino. This is used to upload a sketch.

9

ok, thank you.
And one more question about powering the ProMini 5V Board.
Can i just get a cheap 5V 1A power adapter and connect it to the Mini? Or is it better to use a 7V adapter?

And than there is a VCC and Raw pin, right? DO i connect the adapter to raw or VCC?

10

The Pro Mini has a voltage regulator.

So you can use that cheap power adapter.
Some of those have an output of 7V, but that is okay.

The power input is at RAW (and GND), the Vcc is the regulated output and if you measure that with a multimeter, it should be 5.0V for a 5V version.

11

great thank you