Simple GSM controller
If you need GSM controller but you are not familiar with microcontrollers then this project is for your. The project consists of cheap GSM phone that has port and can be configured to auto-answer incoming call, DTMF decoder (MT8870) and a few controlling relays.
How it works?
First call this GSM controller with your cell phone. By pressing on any key on your phone’s keypad, GSM controller will receive that DTMF signal and MT8870 circuit will set the appropriate binary value on it’s data pins Q1-Q4. Those data pins will turn on or off relays connected to them. You can add SN74LS138 or SN74LS154 to control more relays ( up to 12 relays ).
Download PDF documentation
Simple GSM controller at instructable
www.instructables.com
