Wireless Communication

Just wondering.. Is it possible to use create an AC on a pin much like PiFM?
I would like to transmit data from one Arduino (Uno) to another using some
form of wireless communication.

I'm guessing it's possible, but I have no IDEA what to use. I'm quite an
experienced programmer, but any directions I can be pointed towards?

Thanks guys! :slight_smile:

You can't do it directly from an Arduino pin. The usual way is to use RF transmitter/receiver or transceiver modules.
They come in a variety of flavours.
Try Googling "Arduino RF module", "Arduino RF Communicatios", "Arduino RF Link" and similar search terms.

NRF24L01 modules, Bluetooth modules, APC220 433MHz transceivers, Dorji DRF7020D13 433MHz transceivers and the cheap Chinese 433MHz RF modules are a few of the options available.

What sort of range and data transmission speed are you aiming for?

OldSteve:
You can't do it directly from an Arduino pin.

I think this should be "you can't easily do it from an Arduino pin".

I have seen microcontrollers used to generate RF directly. Just connect an antenna to the I/O pin and it can broadcast very noisy RF. Don't leave it connected long or the FCC will come knocking.

I have no idea how to do this with an Arduino or on which models it's even possible.

DuaneDegn:
I think this should be "you can't easily do it from an Arduino pin".

I have seen microcontrollers used to generate RF directly. Just connect an antenna to the I/O pin and it can broadcast very noisy RF. Don't leave it connected long or the FCC will come knocking.

I have no idea how to do this with an Arduino or on which models it's even possible.

Ha. Fair enough. It would be very low frequency, but it would still be RF.

@SirColumbus, neither of us is recommending that you do it this way. :slight_smile:
(I'm not, anyway.)

Better to just buy something along the lines of what I suggested earlier. Those cheap Chinese modules don't work too bad, albeit at a slow data rate and usually with a relatively short range.

I've been trying not to link to the Parallax forum but a lot of the electronics projects I know about, I learned from the Parallax forum. This includes using a microcontroller as a radio.

I tried to find a similar example using an Arduino but couldn't.

The project linked above uses the microcontroller to receive radio signals but I believe it is also possible to transmit radio signals with a few passive components and a microcontroller. It's a long thread with a lot of interesting information. The author of the original post, Phil Pilgrim and one of the thread's commenters, Beau Schwabe are really smart guys. There's a lot of heavy theory in that thread.

I know it's possible to transmit TV signals with a microcontroller and a few resistors. These signals aren't very powerful.

OldSteve:
Better to just buy something along the lines of what I suggested earlier.

I'm a fan of the Nordic nRF24L01+ transceivers. These can be purchased for less than $2 and I think they work great. I believe the Nordic modules can transmit 2Mbits per second. The modules have all sorts of cool features like pipelines and error checking.

DuaneDegn:
I'm a fan of the Nordic nRF24L01+ transceivers. These can be purchased for less than $2 and I think they work great. I believe the Nordic modules can transmit 2Mbits per second. The modules have all sorts of cool features like pipelines and error checking.

I've been meaning to get a couple of those to try out.
As you probably know, I usually use APC220 modules. That's mainly because they're easiest to use, (transparent serial interface), only require one pin for simplex or two pins for half duplex/duplex, and have a very long range and good punch-through for obstacles like brick walls etc.
They cost a lot more though, at $40 a pair, and for many things the cost isn't justified. I'd like to keep a few nRF24L01 modules around for some projects. Actually, I'll order a couple right now while it's in my mind. :slight_smile:

Edit: Done - AU$1.29 each, delivered. I ordered 6. They'll be fine for my short-range projects like robots etc.