Hi all,

My group is working on telephone remote control. We built a devices installed in telephone line from residential house that can turn on certain things around the house such as light, tv, etc. We have a few problem right now such as caller ID detection.

We can get signal and decode with (DTMF: MT8870) and microcontroller (PIC16F84A). Our device pickup the phone after 3 rings and able to turn on various things now. We are trying to write a code receive caller ID, so microcontroller can pickup the phone automatically, but we are not able to find any valuable information to finish it.

Please help us

 

Caller ID is not furnished automatically. You have to pay for the service to be added to the line.

With ID enabled, the data are sent as an ASCII string between the first and second ring.

Google brings up 12,200,000 hits on "caller id". Try this link - http://electronics.howstuffworks.com/question409.htm.

 

Thank you for your reply,

I understood that information send between first and second ring, and residential homes have to enable it in order to acquire information from incoming calls. But, how to get these information from picbasic program or assembler codes. Thanks again

 

The information does not come from the assembler codes - you have to arrange an interface to capture the ASCII (probably as FSK tones) sent between rings and input it to the PIC. Then the uC will have to interpret the ASCII string in some meaningful way.

 

HOLTEK makes an IC part number HT9032 that when connected to a microcontroller running the appropriate software can extract the caller-id text string.

hgmjr

 

I saw the circuit schematic work as "Caller Identification". I think the problem we have right now is assembler codes. Our device understood output from callers such as "press digit" only AFTER this device "pickup" the telephone. We can't capture anything if the phone is off-hook and "ring ring ring" from incoming calls. Any guess?

http://www.geocities.com/amanjeetindia/caller.gif

 

I know US use HFK instead of DTMF. I installed one chip "HT9202C operate 4MHz" found from broken phone to use in our device. I captured some binary number (alot ex: 0000000011111110101101010) from pin DOUT, and I have no idea how to decode them. Our microcontroller operate speed chage to 20MHz. I am not able to decode these series numbers on first and second ring with speed operating 5 time faster than the HT9202C. How to decode them. Please help

datasheet HT9202C
http://doc.chipfind.ru/pdf/holtek/ht9202c.pdf