Help with understanding XBee's before purchasing

Projects Networking, Protocols, and Devices
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Good afternoon,
To start with Im a newbie, so please be pateint with me :slight_smile:

Ive decided to make my own alarm system for my home, and decided to use Ardunno, and XBee communications between the PIRs and door sensors. But I have 2 questions before buying all the kit.

As Im just reading the sensor (PIR), can I just connect the XBee directly into the PIR to transmit what the sensor sends, ie low for no movement, and when movement is detected High? Or do I need to connect every PIR to a Arduino board and then an XBee to transmit the status of the sensor?

Do I just need to 1 XBee for each Sensor, and then one for the Ardunio and the Ardunio can read the state of all XBees on the PAN, or can I only do XBee to XBee? I have not seen any documentation for how to read what XBee is sending the data on the PAN.

Thank you in advance, and Im sorry for my newbiness :slight_smile:

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As Im just reading the sensor (PIR), can I just connect the XBee directly into the PIR to transmit what the sensor sends, ie low for no movement, and when movement is detected High?

If the PIR outputs a 3.3V signal for HIGH, it can be connected directly to a digital pin on the XBee (as well as ground, of course). The XBee needs to be configured to care about the state of that pin. No Arduino is required, though.

Do I just need to 1 XBee for each Sensor, and then one for the Ardunio and the Ardunio can read the state of all XBees on the PAN, or can I only do XBee to XBee?

These are not mutually exclusive statements. You can only do XBee to XBee communication, but one XBee can listen to several XBees. An XBee can talk to one other XBee, or can broadcast to all other XBees on the same PAN ID, depending on how the XBees are configured.

You want one listener, and several talkers. The issue that you may run into with this configuration is that two talkers may try to talk at once, confusing the listener.

I have not seen any documentation for how to read what XBee is sending the data on the PAN.

If you mean WHICH XBee is sending the data, you'll want to put the XBees in API mode. The packet that each sends, then, contains the ID (MY) of the sender.

Im sorry for my newbiness

So, buy a few, experiment with them, and get over being a newbie. :slight_smile: