People have been making these DTMF phone dialer devices for years, here’s how to make one with a PIC microcontroller.
The company I work for recently upgraded their phone system. They got a new IP phone system that can supposedly do everything – the new phones have big LCD screens with fancy menus, lots of different modes, PC connection for remote control of the phone, e-mailing voice messages, and tons of other features. All that said, there was a critical piece missing from the picture – a way to dial a stored number while already in a call. This is a feature I use often – I’m using a calling card to call home and I need to first dial the 800 number and then send my calling card pin number. Well, believe it or not, the cool new phones with all the fancy software couldn’t do this and I had to switch back to pencil and paper! “We will include this feature in release 8.0 or possibly 8.5” was the response from the phone company. Yeah right, like I’m going to wait for 8.5!