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Telephone line connection [Caller ID project]

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New Member
hi everbody,

i started a little project , which is about building a caller id circuit around an atmel 8bit mcu.

i don't plan to use any decoder chip nor module for that, the demodulation should be done on the microcontroller.

i found somewhere a good software based fsk demodulator for atmega8 i believe, though i don't think that the software part is that difficult (worst case : i use two mcu's :) )

i'm in the process of designing this thingy, and first started with the connection to the telephone line.

For debugging puropses , i plan to connect the phone line to the sound card so i could pick up easily any signals flowing through and hopefully do some digital processing in matlab

what do you advise me , specially regarding ratings , and protections i should use to connect my phone line to the sound card ?

comments / ideas / suggestions are welcome.

thanks in advance.


Well-Known Member
Most Helpful Member
Where are you located? Phones are different depending upon the country.
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