phone dialer

Discussion in 'General Electronics Chat' started by R!f@@, Apr 10, 2012.

  1. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
    8,750
    759
    I need to make this simple but yet effective. Component is not a problem. I can probably get anything now. :D

    All I have is N/O contact from the alarm.
    I need to make a circuit to dial a programmed no. when I get the signal. land line phone, dialing no. has +960 XXXXXXX . These are the character amount of our telephone no.s

    On activation the circuit needs to pick up the line, wait for dial tone and then dial the no. If bzy, try again. Wait till the party picks up the call and enter acknowledge numbers such as a numeric code like 0000 ( programmable). If entered correct code deactivate further dialing, If hanged without code. Redial again.

    So what are ur ideas on this.
     
    Last edited: Apr 10, 2012
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    Way way back I did some experiments on POTS phone lines. I vaguely remember using a Radio Shack 1000 ohms to 8 ohm transformer ( 273-1380) to get a cassette to play over the phone line. I believe connecting it caused the line to connect to the central office (ie, pick up). The connection is 1000 ohms -> phone line, 8 ohms -> cassette speaker output.

    So anything capable of making the touch tones could play thru a speaker amp to this transformer. You would have to experiment to find a good level. The tones are a mix of two frequencies, there used to be an (Signetics?) IC that could generate these but I dioubt it is still in production.

    Radio Shack still sells this item some 40 years since I got my first one.
     
  3. gerty

    AAC Fanatic!

    Aug 30, 2007
    1,153
    304
  4. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
    8,750
    759
    C'mon guys. I am thinking of a micro

    Can 12F629 do it ?
     
  5. bertus

    Administrator

    Apr 5, 2008
    15,646
    2,344
  6. gerty

    AAC Fanatic!

    Aug 30, 2007
    1,153
    304
  7. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
    8,750
    759
    Humph !...Grump!
     
  8. gerty

    AAC Fanatic!

    Aug 30, 2007
    1,153
    304
     
  9. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
    8,750
    759
    I wanna find a way to do it? don't wanna buy stuff
     
  10. gerty

    AAC Fanatic!

    Aug 30, 2007
    1,153
    304
    .
    It's a project with schematic and source code, not a finished product.
     
  11. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,769
    969
  12. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,769
    969
    R!f@@ likes this.
  13. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
    8,750
    759
  14. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    Seems like you want us to find a way to do it.
     
  15. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
    8,750
    759
    But I can't seem to get anywhere with it.
     
  16. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    This page has a project of a PIC generating DTMF tones itself, without the need for a special 8870 DTMF chip;
    http://www.romanblack.com/SG/SG_tutorial.htm#DTMF
    Source cod eis provided, the PIC can be as small and cheap as a 12F series as long as it has a single PWM module (the dual frequencies are generated fron one PWM module, using an algorithm).
     
    R!f@@ likes this.
Loading...