USB serial + serial communication over RF

Is this possible?

I want to use the USB side of a Arduino NG (ordered , shipment delayed :() as communication to a pc, do some processing on the atmel, and send instructions through RF by serial communication to other atmels with RF radios.

Concrete question:

Do I need to do software serial for the RF? Or can i use the rx/tx pins for it, without messing up the USB serial part?

You’ll need the software serial for the RF, if you want to communicate at the same time with the computer via usb. The Serial<->USB uses already the UART (RX/TX pin) of the Atmega8.


Hmm too bad :(

Ok thanks for the clarification. :)


you might want to look at the Xbee module discussed in other parts of this forum. It can do the kind of networking you want. Unfortunately, as is said above, you'll have to use the SoftwareSerial as the HW port is taken by talking to the PC.

Or, if you need more hardware serial ports, you might try a Wiring board for the master module, as it has two.


Isn't all that Zigbee stuff mad expensive?

The radios I have as target now cost about 8euro an end

Also my 'slave' side just has to receive, it never sends. And the master never receives, it just sends....


yes the zigbees are about 25 USD a module, but they are engineered for multiple-point systems, collision detection, channel ID's etc. You get what you pay for... D

I'm working on exactly this style of project now using cheap 433Mhz xmit/rrecv pairs. I have got the transmitter working fine (using TX pin) with the connection to the computer at the same time but the receiver is still having problems starting up on the RX pin for a reason yet undetermined.

That said, I can get it working with a manual tweak and using h/w send and receive works fine.

Try these ones on Sparkfun (or ones like them) and see how you go.

That page also has code and a walkthrough for doing it all on just doesn't seem to work with either my versions of the xmit/recv or maybe its the newer Arduinos.


Woa nice link.

Sparkfun is a bit out-of-my-continent though :) I've read on that he only got 1200 baud to work. Maybe you just need to try that?

Anyway you are still able to use hw serial :)

I'll fill this topic up with what i'm doing when i finally get all my hardware delivered.

You can read out my project on

They are out of my continent as well....I'm in Australia, but their shipping is a good price and very if you have a few things to order it may be worth it ;-)

Well i'll check it out someday. Right now i already ordered everything from which has free shipping :P

But it's just the parts for the initial tests , so maybe i'll hit spark up for the rest....

FYI The radios i now have in my possession :