Hi!
I have emonTX v3 connected to RPi using RFM12B.
I have multiple(12) temp sensors connected directly to Raspberry PI. Because based on received values from temp sensors, RPi will switch some relays on or off.
1) Is it possible to feed temp data to emoncms.org?
2) If I`ll connect DS18B20 directly to EmonTX, how I can get data in RPi to use temperature values for calculating and uploading to thingspeak.com?
3) What is maximum DS18B20 can be connected to EmonTX v3?
Re: Feed data from RPi
I cannot help you with the questions about the Raspberry Pi - there are others here who know far more about that.
The number of temperature sensors that you can connect to the emonTx depends heavily on the way they are connected and on the lengths of the cables. There is an article in Resources > Building Blocks about the DS18B20, and links to further information that goes into great detail about this.
Of course, you will need to modify the sketch if you want to read more than 6, and there is a limit also on the length of the data that can be transmitted by the radio link.