Please help me decide. Single vs Multisensor

[webstor]

Hi guys,

at the moment I have about 30 sensors, all single (1 Sensor, 1feature).

Should I go combine sensors, as example temp with motion and fire?
Or should I build a sensor for each purpose?

Thanx.

[gohan]

Depends on your needs, there is no good universal solution

[AWI]

@webstor that's a pretty open question.. Combining sensors is mostly a matter of efficiency. Especially combining low power sensors can save you a lot of batteries, apart from saving on the number of radio's and Arduino's.

[webstor]

Thats true, but at the other hand, more sensitive to errors.

[AWI]

@webstor can you be a little more specific? Do you mean programming errors

[rejoe2]

Hello together,

there is no "right" or "wrong" answer to this questions imo. Both concepts have their two sides.

Personally, I prefer to go the multisensor way (and also use RS485, which limits the numbers of sensors to 32 per gateway with standard interface boards). In addition to that I also like the idea to let the arduinos decide (some) things locally or make them configurable to some extend. So things may not become completely out of controll in case there is (temporary) no controller.

Advantages:

• Less parts, especially power adopters/batteries,
• less "optic irritation"
• better use of arduino potential (use of more than 40% of the memory, not sleeping all the time)
• Less RF, means also lower risk of RF conflicts (or best: no RF at all => RS485)
• in case of e.g. failure or power off, I will most likely notice this earlier because of the bigger "footprint"

Disadvantages:

• its (sometimes) hard work to get things working (but also fun and satisfaction )
• higher risk of messing things up because of bad code (I am just a beginner in programming. This is more related to distributed logic as mentioned above; just combining some simple examples isn't rocket science...)
• in case of e.g. failure or power off, a multisensor has the bigger "footprint"

So it's up to you which way to go (or to which extent, to be more precise).