Since i was posting in the wrong place i am moving my questions into this forum. http://forum.arduino.cc/index.php?topic=166681
Well i did a little reading and i think that Moteino (868Mhz) as sensor nodes and a arduino with a ethernet shield and a RFM12B transceiver as a basestation. I wanted to use 868Mhz version because i live in the netherlands, so the 915Mhz is out of the question. And because of the range. But as i said before, my knowledge of RFM is not that big... So if anybody thinks this is a mistake, please let me know.
Because i live in the netherlands, and ordering the Moteino can be a hassle. So i want some certainty about using the Moteino and RFM.
For one, how can the arduino differentiate between multiple nodes? How can i schedule the moment of probing? In my simple way of viewing this is putting a sleep in the code, but i am afraid that the nodes will keep transmitting, which is not very efficient. Or should i let the Moteino transmit data and then sleep? But what will happen if two Moteinos transmit at the same time?
The basestations only job is to gather the data from the nodes and then post it to a remote server. So i can store it in a database to later create a nice interface for it.