SparkFun Forums

[kimmi]

Hi,
I have to make some kind of TX/RX for many (300 units) smoke sensors in a building

ranges about 300 Meters to RX unit
every smokealarm will have a AVR controller that send the data to master RX unit
The data will be like a offices name and the number to call
what type of tx/rx will be best to use ?

it is in a building 15 stories high about 30 offices pr floor

If 1 rx cant do this then 1 rx unit pr floor will do ..

[Nullz]

Sounds like an excellent project for a MESH network.

The MaxStream XBee (1mW) units are fairly cheap. Even the XBee Pro (60mW) are priced fairly. You can also get volume discounts.

The data rate is only 115.2KBaud but thats plenty if all you need to send is location and status.

When you say 300m to RX unit, what do you mean? Do you mean the max distance between any smoke detector is 300m? With MESH, each node (smoke detector) will act as a relay. As long as each smoke detector is within 100m of another smoke detector or your base unit, you should be able to see it on the network.

Nullz

[kimmi]

hi Nullz,
Tanks you for this info ...

When you say 300m to RX unit, what do you mean? Do you mean the max distance between any smoke detector is 300m?

I mean all sensors is max 300 m from RX unit

But if i can get the MESH network to work then i have no problems ...

I try find more info for MESH network & Xbee it looks sa the way to do this

If you have any more info about this pls tell me ....