A simple Open Horizon service that speaks the LAN IP address through the default audio output. It does this over and over forever, every 30 seconds.
Of course, if you wish to hear the speech, you will need to plug in some earphones/headphones or if you have configured your Raspberry Pi to use only the HDMI for audio output, then you will need to connect an HDMI cable to something that can emit audio.
This little example uses the default English espeak voice for this (which is pretty horrible), and sends it a text string that looks similar to this:
Your eye pee address is 1 9 2 dot 1 6 8 dot 1 dot 1 2 3
The espeak tool can pronounce many other languages, so hack away if you want that. Here is some documentation:
http://espeak.sourceforge.net/docindex.html
By default it only looks at the eth0 interface. If yu plan to use WiFi then edit the Makefile to specify wlan0 as the INTERFACE_NAME. If deploying wiith Open Horizon, set the INTERFACE_NAME as a Service variable.
Of course, specifying the INTERFACE_NAME is inconvenient. You could do something better, like determine the hosts's "default route" and then find the host interface that was on that network, and then announce the IP address of that interface. If you did that, then then you would not need to pass any INTERFACE_NAME at all. But I was tooo lazy to code that! :-)
This has currently only been tested on a few Raspberry Pi models.