iPhone proximity detection using wifi

As my iPhone automatically joins my home network once I get home and press the main button, I thought this could be used as a trigger for some home automation ideas I have, especially disarming the alarm system for example.

I could detect the iPhone by pinging the broadcast address with a script and th开发者_运维百科en look for it's MAC address in the arp cache, but this would have to be done every 15 seconds or so to be of any use. This really doesn't seem like the most elegant solution though.

Can anyone think of a better way to implement a check like this? I suppose one could assign an IP address dependent on my MAC address, then I would know what to ping, and could thereafter check the MAC address to keep things secure.

Just suppose I cannot assign a DHCP IP based on MAC address, as the problem of being able to find the MAC address on the network is the part that really interests me.

Secondly I noticed with tcpdump that the iPhone seems to talk to itself all night, but only some sort of Ethernet frames:

23:59:59.740097 00:26:08:ae:ed:eb > 00:26:08:ae:ed:eb, 802.3, length 70: LLC, dsap Null (0x00) Individual, ssap Unknown (0x20) Command, ctrl 0x33: Unnumbered, 23, Flags [Poll], length 56

This happens every 2 minutes.

How could I monitor this traffic so that my "home" knows I am still there using a program? Could be good to automatically alarm the house when I am no longer there...

I think your router here should be the point of control... If you can log the devices that are logged on to the router you can disable your security based on that info.

If you have an openWrt compatible router http://wiki.openwrt.org/toh/start you can certainly extend to get the functionality you want.

Here is a link plugin for the indigo home automation server that does what you want to do bij logging the info from his router. http://www.perceptiveautomation.com/userforum/viewtopic.php?f=19&t=6876&sid=07a351fa04c2eadcd2d3813afc72ae5a

Note: it's really easy to spoof a mac address so might be interesting to have some other verification too :-)