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Yes. But you can still use the RPi as a 'forwarding only' base if you wish without running emonCMS on it and without using local storage for your energy data.

Great - thanks. That makes sense... I think I'll probably opt for the nanode, because its power consumption is lower and it works out a bit cheaper to buy... And using an externally-hosted emonCMS sounds like a good way to do it for starters.  I'm guessing that the emonGLCD talks to emonCMS to get the data to display... Or is it actually just talking to the base station to show realtime info?

I might then add a RPi later on, to run emonCMS locally - sounds like that's a good thing to do long-term.

Tom

With my system I measure data using three different emonTX units each working on different channels.  I use a Nanode RF SMT to poll all incoming data and transfer it directly to the emoncms web site where I display my data using a dashboard that I have created using the tools available.

at the same time I also have an emon GLCD display polling the wireless traffic and extracting data directly from the channel where the main emonTX is generating data (its the unit measuring the consumed and solar power and temperatures). In effect the GLCD is running in tandem with the Nanode as it never tries to read anything that the Nanode transmits (all transmission being cabled Ethernet anyway).

there will be an occasional data collision but enough data is being read by the Nanode and the GLCD, listening to just a single channel picks up pretty well every packet ever sent.

Hope this helps rather than confuses you!

Just to reinforce what Series530 says - (almost) no data comes back from emonCMS. The GLCD gets the time from emonCMS, but it gets all the rest of its data by radio from the emonTx(s).

Very true Robert. I had forgotten about the time function - most likely because I make no use of it in my sketches.

My GLCD tends to act as a pretty dumb display device because the spare memory available once even a basic sketch is added is pretty finite.  It's always a trade off in functionality as a consequence. I find that displaying sensor data is more useful than time information. My main processing unit is emoncms and anything affected by time is done on there and shown on the web page instead.

Thanks Ian and Robert - that's much clearer now! So EmonGLCD is more of a realtime display, gleaning info from the EmonTX transmissions and displaying whatever the latest reading is. That sounds good - I'll probably go for a single EmonTX (which I'm building using an existing Arduino and the EmonTX shield), and then a Nanode, and maybe add the EmonGLCD later on... Or perhaps even just use EmonCMS as the main "display" within a web browser and not both with the EmonGLCD just yet. Looking forward to getting up and running with it all, anyway!

Thanks for all the help and info :-)

Tom