NRF24L01 - Two way communication traffic demo

@Pugwash

Just out of curiosity, what's the difference between using radio or network to do the reading or writing?  I've been experimenting with radio read/write previously, and it seems to work in quite a similar fashion.

@frogandtoad

What do you mean by "network"?

@pugwash

What do you mean by "network"?

Ok, just to clarify... I've seen the use of different libraries, using similar code:

network.read/write(...) vs radio.read/write(...)

What exactly is the difference, when it appears (at least in my testing), that they look to offer the same outcome... what am I missing?

@frogandtoad

network.read/write(...) vs radio.read/write(...)

"network" and "radio" are just the names of the declared objects, found above the setup() loop

frogandtoad.write would be perfectly valid if "frogandtoad" was declared as the object.

And in the above code, "radio" is an object within the "network" object.

I also believe that the "radio" object inherits properties from the "network" object.

radio.begin();
network.begin(90, this_node); //(channel, node address)

Note that radio is initiated before network, if the order was reversed this would not work.

I hope that clears it up!!

@pugwash

Yes, I do understand they are objects... no problems there, and I have also seen that radio is passed to the network constructor, and this is what I wanted to know... are they essentially doing the same work, but just different libraries?  Is there a case where one of these implementations should be used over the other?  IOW... do they have different applications?

@frogandtoad

Is there a case where one of these implementations should be used over the other? 

No, they are not interchangeable! Network object needs the radio object to function.

To understand this better you should take a look at the RF24.cpp and RF24Network.cpp files in the Arduino/libraries/RF24 &  Arduino/libraries/RF24Network folders.

@pugwash

Thanks, I can look at the files, but that won't tell me when to use one library over the other.  Like I said in my original post, I have been able to communicate with radio.read() and radio.write(), and quite successfully... However, I'm still not sure under which circumstances I would user network.read() or network.write(), because from the examples I've seen posted here so far, I don't see what one can do better than the other?

Does that make sense?

From what i read in the doc, the RF24Network (using the underlying "optimized" RF24) introduces an OSI Layer 3 with message acknowledgement and routing (equivalent of IP in the TCP/IP network stack) :

http://tmrh20.github.io/RF24Network/

So RadioA could send messages to RadioC via RadioB for example (see the RF24Mesh for much more complex examples, it is built on top of RF24Network which itself relies on "optimized" RF24)

@frogandtoad

I haven't used radio.read or radio.write in my code. In my code above, the radio object is initialised for use by the network object, and in the loop(), only the network object addressed. So if you have seen this usage, it may be in conjunction with other libraries.

All I know is that my code functions 100%, without radio.read or radio.write!

Thus, a comparison of these object.functions is a complete waste of time.

@pugwash

Ok, maybe not your code specifically, but some code you have helped with perhaps?.  I wasn't questioning whether your code worked or not, but if you haven't used radio.read() or radio.write() to communicate with these transceivers before then that's fine.

A waste of time?... not if you want to learn!

@zeferby

Sorry, I missed this post earlier.

Ok, that makes some sense, if it offers more functionality, specifically for dealing with the OSI model.

Thanks for the information, I will read up on it further.

Posted by: @frogandtoad

@Pugwash

Just out of curiosity, what's the difference between using radio or network to do the reading or writing?  I've been experimenting with radio read/write previously, and it seems to work in quite a similar fashion.

I think I have got the answer now.

Both are simplex communications but network does not have to be explicitly told that it is the transmitter or receiver during setup, whereas radio does need to be set to transmitter or receiver programmatically.

radio.stopListening(); & radio.startListening(); are not required by the network station to change its status.

Once set up:

RF24NetworkHeader header;
int incomingData;
network.read(header, &incomingData, sizeof(incomingData)); // Read the incoming data

is all that is required to receive data and:

RF24NetworkHeader header(node01); // (Address where the data is going)
bool ok = network.write(header, &outgoingData, sizeof(outgoingData)); // Send the data

is all that is required to send data.

@pugwash

Nice!