This is my first post and I am looking to buy parts and build my first energy monitor. I have to choose between building an emonTx system or building something similar to the jarv.org setup. As far as I can tell, here are the advantages of each system. Help me choose!
>> emonTx advantages:
Simpler, great community of support (which I will need!)
emoncms interface looks better and easier to setup
Ability to easily add LCD down the road
>> Jarv.org advantages:
Uses ethernet; does not require a base station
Lower cost, since I don't have to build a base station
Lower power consumption (I assume), which is great since that's a main point of this exercise
Re: Which Energy Monitor system to build?
Hi JP and welcome!
What I think is a cool configuration is a Raspberry Pi with the RFM2PI + emonTx and a emonGLCD if you like.
The cool thing about the RF part is that you can put the LCD where-ever you want and also you don't need a RJ45/network connection near your fusebox for the emonTx. I think it gives you more flexibility.
You also can extend these emon systems with all kind of nodes (Martin Harizanov's Funky sensor, Jean-Claude Wippler's JeeNodes) or you develop an add-on yourself :-). Anyway, I think that the Open Energy Monitor platform is a really cool, open and extendable one!
Re: Which Energy Monitor system to build?
Thanks Fluppie! You have convinced me that OpenEnergy is the way to go. Now the choice is between the RasberryPi and the NanodeRF for a base station. I know the Pi can act as a web server but I am not sure why this is a huge advantage compared to hosting with a remote server. What do you think?
I am concerned that the Pi may have more power consumption than the NanodeRF, important to me since this will be on 24/7. How many watts is yours pulling?
Which version of the Pi are you using? I am assuming B with 512MB since this comes with RJ45. Do you need the B with RJ45 in order to interface with the home network, or can the RFM2Pi connect to my home network too?
Re: Which Energy Monitor system to build?
I would go for the Raspberry, it's easier to configure and there's a ready to go SD Card image :-).
https://www.dropbox.com/s/5odwpcrgpsqoxso/emoncmspi.zip
To me it's handy, when the hosting company is down or my internet connection is down, my readings won't get lost. That's why I want my own local copy of emonCMS and I'll forward the analysed data to a remote server (built-in in the RaspberryPi module of emonCMS).
Yes indeed, I ordered mine 3 weeks ago from Farnell/Element14. It's indeed the B version with 512MB RAM.
I haven't measured it yet, because I'm feeding it from the USB port of my server :-). But this means, not more than 500mA thus maximum 2.5W. But with a 'real' supply model B can take up to 700mA, 3.5W.