Archived Forum

" I would like to power up my emontx with 3.3 V battery. Is it possible to attach 4 DS18B20 modules?"
Yes and no. Yes you can connect 4, bearing in mind that the wiring topology needs to be thought about - there is plenty about that on Maxim's website, but as they are powered continuously on the V2, battery life will not be good.

"Can I attach 2 emonTH modules at the same time to the emonTX?"
You don't attach emonTH modules to the emonTx. They are stand-alone, and communicate directly with your Base. You can have many emonTH modules, but you will need a programmer to change and reload the sketch because the node number needs to be different in each (else you don't know which is which).

thanks Robert

And how many emonTx devices can attach to 1 raspberry pi?

There are 30 readily available node id's on an RFM network and by default emoncms is capped at 32 nodes, however, these restraints can be overcome if you want more devices and to be honest a single RFM network will become too congested and suffer lost packets if you "just" hook up 30 devices.

So it depends very much on what you want and how much you want it. If you are just looking to hook up a couple of emonTH's and a couple on emonTx's you should be fine. and maybe ok upto 10ish devices without modifications, depending on the frequency and size of the transmissions in question.

Paul

alright, that more then enough for me.  

i would like to connect 2 emonTH en 2 emonTX to 1 pi. Now I know that it will work.

Thanks again