I am planning to set up Home Automation System to my reading room using DTMF Technology. For that, I have searched different websites and found a post - DTMF Based Home Automation System Circuit.
That circuit seems to be simple and interesting. But, they mentioned few limitations.
1) It is limited to 16 tones only. Is it not possible to extend it by adding any other component?
2) It is mentioned that it has no security. Is it not possible to solve this problem by setting up a security password?
If anybody have an idea about it, let me know the solution. I would like to implement this same circuit to my room on next week.