I'm a completly new user of Arduino, and before buying some materials I wanna know you point of view. I'm really interrested in building my own domotic system using Arduinos and sensors. I'm sorry to ask the question again, but there's some black dots in my thinking.
The main aim of my project is to build a main "central collector" using a Arduino Uno and Ethernet Shield which will be in charge of collecting information from wireless sensors and presents the results in a web page.
This first part doesn't seem to be really difficult but for the wireless sensors...
I would have little, cheap, and low power consumers wireless sensors. My choice is perhaps to use Arduino Nano cards, with the sensor of my choice. To communicate with the main "central", I thought about RF Transcievers from Sparksfun. The main problems stays when there's is more than two sensors, to allow them to communicate easily and to be identified.
I thought about two ways of implementing this solution and as daily arduino users, I wanna know your point of view.
Solution 1 : To allow sensors to communicate easily without interfering with others, each sensors has to be alone to transmit. Using time slots division, each half seconds could be reserved for each sensors. When a new sensor is connected it has to be synchronized using the same clock. When some of them has something to say, they just use their dedicated slot. Main central will be able to recognize the sensors by the slot on which its sending information.
Problem : when there's a lot of sensors... waiting times could be long...
Solution 2 : The central and sensors can play a Master/Slave game. The central could ask sensors one by one if one of them has someting to transmit, and if it's the case, the sensor sends information.
Problem : each sensor is periodically waked up...
What could be, for you the best solution ? Whatever the solution, I think I will only need Arduino Nano + Dedicated Sensor + RD Transciever. This is the cheapest solution I found. I find xBee, Bluetooth or Wifi solution too heavy and too expansive to build what I want.
Thanks a lot in advance for your replies,