Simple Wireless Connection

Hey all you Arduino gurus out there. I am looking for something simple, and throughout all of the forums and google searches that I have performed, I cant find it. LOL :)

Here's what I have: 2 - Arduino Duemilanoves 1 - Motor Controller 1 - 2km long range RF link kit (transmit and receive)

Here's what I need to do: I need to control the motor controller on the transmit side through the serial interface and make things happen on the motor controller on the receive side. I have the code written for the motor controller and everything works beautifully through the USB, but trying to go wireless is a pain in the arse!

I'm unsure about how the transmit and receive code work as well. Do the codes need to be uploaded to their respective Arduinos or does all of the code go through just the transmit Arduino? :-/

Im also confused on the wiring aspect of this project as the supplier has no code or wiring information about the transmitter/receiver. If I could get someone to send me something basic, then I can work around the rest of it. I just need a little push in the right direction. :-/

Thanks for the help if you can help. If you have more questions let me know and Ill answer what I know. ;D

This is the link for the transceiver/receiver:

Seems like all the information you need is right there in your link.

First off, don't expect 2 km; that's probably on a clear day, in the middle of a featureless open desert, with proper matching antennas, a booster, the wind at your back, and a prayer.

Ok - maybe not that severe, but it will only occur under "ideal conditions", and "line of sight". If that still works for you, then read on!

So, first, you basically have to set the "codes" used by the transmitter and receiver by creating solder jumpers across pads. Set them the same way on both ends, bit 1 thru bit 8 (8 bit code, so you could in theory run 256 of these).

Then, whatever 4-bit code you apply on D1-D4 of the transmitter, will appear on pins D0-D3 of the receiver; I don't know why they labeled them like that, but they did. Also, when pin VT of the receiver goes high, then you know you can read D0-D3.

So, on the transmitter, you output the 4-bit piece of data to D1-D4 of the transmitter using 4 digital I/O pins on one Arduino; since you have no way of knowing if they arrived ok, put in a slight pause (really, you should get another pair of the transmitter/receivers, give it another code, then set up a comm protocol to handle all of this) before you transmit the next sequence.

If you need to transmit whole bytes, you will have to do so 1 nibble (4 bits) at a time.

On the receiver side, you hook up VT and D0-D3 to five digital I/O pins on the other Arduino; have the code check for the pin connected to VT going high, and when it does, read the pins for D0-D3, and reassemble the data as needed. You might want to set the pin VT is hooked up to up as an interrupt (ISR), so that when VT goes high, the interrupt is triggered and the data read at that moment.

That's basically it, at least from my cursory glance.

Finally - if you need two-way (duplex) communication over distance, XBee or WiFi is going to be the better (if much more complex) method than these modules; these wireless modules were more intended for simple remote control (without feedback) and applications for remote sensor monitoring (where one-way comms isn't a big deal). Keep this in mind for your application (I don't know what it is; maybe it is a simple gate opener - but if it was a remote-operated robot or something, I wouldn't use these).


Cool, thanks for the reply. Ill have to solder the transceiver / receiver modules to the LOW end and see what happens.