Feseability of new Arduino Home Automation project

Hello, everyone.

This post contains a lot of questions about different areas whose common end is understand the feasebility of my project. Therefore I think Project Guidance is the most appropriate section for posting.

I have done most of the examples distributed with the IDE, and I have to confirm arduino is a great platform!

I am now embarking on a home automation project for which I need some guidance.

I have to

  • turn on and off, as I request from my Smartphone App, some 30 sensors through transistors ( probably BC337-40);
  • monitor that such sensors are working properly throug analog input pins;
  • read sensor output through analog input pins

Before buying all components, I need to ensure that what I have in mind is feaseble:

  • enable/disable these sensors by providing 5V each
  • communicate with the sensors through long wires ( between 10m and 30m).

Since more pins than available are needed, I am thinking of setting up arduino on a breadboard as detailed at http://arduino.cc/en/Main/Standalone and then add the pins I need. Would that be to difficult to do? I have seen there are shields and mux/demux solutions for this. However I think that just adding pins to the circuit in the breadboard would be easier. Can this be done?

For switching sensors on/off I am using the circuit shown in the images attached. Is there any change that I can share such circuit among the different sensor, or do I have to create one for each of them?

image4.GIF

What is the measurement accuracy requirement? If this is a very noisy environment (Industrial) I would be concerned about the 30 meter wire length degrading the analog signal. In a quiet environment you can get away with it but the most robust approach is an Arduino per sensor and talk to them serially. DFRobot has a Leonardo Compatible for $7.10 each.
http://www.robotmesh.com/beetle-1pc?gclid=CjwKEAjw456hBRDQ4eqg8MzA2W0SJABI2gJ8b4oTbRIimeo_nsub1dQ5wLstCF5pqQvE-dGI4ZSn8xoCTQ7w_wcB

ok thanks fot your response. since 30M is the maximum length and the avarage is 10mts, I am considering splitting the project into two or three arduino maximum.

In this scenario, since more pins than available are needed, I am thinking of setting up arduino on a breadboard as detailed at http://arduino.cc/en/Main/Standalone and then add all the pins I need. Would that be to difficult to do? I have seen there are shields and mux/demux solutions for this. However I think that just adding pins to the circuit in the breadboard would be easier. Can this be done? How would I go about this?