I'm wondering if there is a way set up a Pi with one of the GSM modules so that I can call it and issue commands with the keypad on the phone..... Press 1 to do this, Press 2 to do that. There would not necessarily need to be any menu or vocal communications from the Pi. The pi could simply pick up, (perhaps a pickup confirmation tone ) I would know the commands, perhaps a beep or tone verification that the command was received. Has anyone done anything like this, I've searched around but not found anything.
I'm not interested in SMS to commands, specifically need a way to call up a Pi and send commands with a regular landline phone (yes they still exist )