Arduino to Arduino wireless

Projects General Guidance
1

Hi!
I have an Arduino UNO board connected to my aquarium an it's monitoring temperature, water level, splis, .. and its connected to the internet via an ethernet shield.
And I now have another arduino mega on my living room, controling lights, temperature, and blinds.

But, now I want to connect the arduino mega to the ethernet and want the arduino UNO to send the information via wireless (2.4GHZ shield) to the Mega and then he will decide what to do with the information.

Is it possible to have this link via 2.4GHZ wireless shields? I just want the Arduino UNO to send the temperature and other variables to the arduino mega and then the mega will do the processing...

Thanks!

2

Short answer: Yes.

Long answer: Yes, but you can run out of pin quickly on the uno I guess.
Try looking into the XBEE stuff:
Xbee stuff from digikey

3

You can get NRF24 modules without needing to use a shield.

...R

4

Easy - there are a bunch of ways to achieve that.

Either use an NRF24, and the NRF24 library

Or use a 433 (or 315) mhz el-cheapo transmitter/receiver pair - There's at least one library for it, the best known being "VirtualWire", but I didn't like it and wrote my own tx/rx code to fling small packets around with. These are really shoddy, but they're like a buck for a pair, and they are okay for small amounts of data at short ranges.

Or use an ESP8266 WiFi module (the $5 serial wifi module), assuming you can scare up some working library code for it - it's pretty new, and code for it is pretty rudimentary (but wait, you already have an ethernet shield? Are you trying to cut the cord? If not, just use that, and get the mega onto your home network with either wired ethernet adapter, or a wifi adapter like the ESP8266, or something more expensive).

Why is your low powered arduino uno connected to ethernet, instead of your mega? I'd typically choose to put the mega online, since it's the more powerful device (more storage, ram, etc), and have it talk to the uno with more basic means, instead of the other way around.

5

If you need to transfer information between the two, you can't use the 433 or 315 transmitter receiver pairs as they are only one way. The 2.4GHz NRF24L01 on the other hand is a transceiver so can communicate both ways.

I would question why you wanted to do all the processing on the Mega, if you have an Uno, it can do some local work surely?

6

thanks for all the answers!
From what you told me i've tried the cheap 433mhz modules.
So now i have one Arduino NANO reading a bunch of temperature sensores and sending throw an 433 transmiter the values and then I have an arduino UNO receiving the values and then sending them to a web server via ethernet. It works perfectly :smiley:

My question now is if i buy another arduino nano + transmiter it will be possible to have 2 433 mhz transmiters and only one receiver? Won't the message be all confused if the timings are the same?