Doorbell and Asterisk

One problem that we have here is missing people who come to the front door when we are in the back garden. I don't want to do anything crude like have a large outside bell so I would like to engineer a solution using Asterisk.

I have search the web for ways to interface with the door bell but I haven't found one that exactly meets me requirements. A common approach is to modify an ATA device to simulate a call when the bell is pushed. I am not keen on this approach so I am going to have a go using 1-wire technology.

I already have some dallas (now maxim) 1-wire bits in the house that I wanted to integrate into the control system. I have a 1-wire weather system on the roof and a few temperature probes, using DS1820, in some rooms and connected to the underfloor heating system. I have never quite worked out how to use them in Misterhouse so the temperature stuff is still a future project.

Interface ideas

When I bought the DS1820s from RS components I also bought some DS2405 which are IO devices. I am going to have a go at using one of these to act as an input device. I have previously used owfs as the software to work with the 1-wire devices. It presents each device as a file

I am thinking of monitoring the file for the input device and when it changes copy a predefined file into Asterisks outgoing call directory. This will cause the internal dect phone to be rung with a callerid of doorbell. I may also call my mobile phone but I will only get the house callerid however, as long as I don't answer the call, the alert will be free.

Progress

I am collecting the necessary bits at the moment and will post more details when I have something working.