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Posted by Tomi Engdahl (194.29.197.25) on May 31, 2003 at 12:33:46:
In Reply to: Home Automation - Controlling Over Phone Line posted by Mr. Jean Fernandes on May 30, 2003 at 19:42:37:
: Dear Sirs
: I am developing a CPU 8051 based in order to perform control on my home. I have a PABX and the idea is to connect CPU on ramal of PABX. So, I am needing :
: - Telephone Front End Circuit to
: - Connect the CPU on Phone LIne
Read http://www.epanorama.net/circuits/teleinterface.html
: - Detect the ring tone.
You need to detect the ring signal on the line.
You can find examples how to make this at:
http://www.epanorama.net/circuits/telephone_ringer.html
and http://www.epanorama.net/links/telephone.html#circuits on "Ring detectors" section.
: - After 3 rings, pick up the ~phone~ and read the DTMF tones.
Software to do this is around this:
1. Wait for ring signal to activate (for first ring)
2. Wait for ring signal to end
3. Wait for ring signal to activate (for second ring)
4. Wait for ring signal to end
5. Wait for ring signal to activate (for third ring)
6. Wait for ring signal to end
7. Turn on the line hook relay to pick up phone
8. Read DTMF data from DTMF decoder
: I am using the MT8870 IC to read the DTMF tones. BUt I dont know how to connect it on phone line (I am needing a circuit)
: So, I am developing a smart phone capable of control lights, alarms, moving sensor, CCTV sequential, and so on. All over phone line.
: Please help me.
The page http://www.epanorama.net/links/telephone.html#circuits has links to telephone based remote controlling circuits quite similar what you need at "Remote controlling using telephone" section.
Those should cover at least the controllign section. Relays activated through telephone line can control practically anything that need on/off control.