Automatic telephone recorder

[James Bond] types and those suffering from a hefty dose of paranoia can now record all telephone conversations. [Trax] built this module that monitors the phone line and starts recording when a handset is picked up. A computer does the actual recording, triggered by the microcontroller via a USB connection.

We like the use of an old PCB for a faceplate, we’ve certainly got some duds of our own sitting around. The three cords are a bit confusing though. One for the phone line, one for the USB, but what does the third do? Is it an audio-out connection?

We’ve asked [Trax] to post a schematic and source code if possible so that might clear up the mystery.

Update: [Trax] let us know that there is a red button with white lettering at the bottom labeled “download”. This contains schematic, code, pcb layout, and PC software. We just missed it the first time around.

Comments

  1. Eddie says:

    External power maybe?

  2. Saydrah says:

    I’m pretty sure the phone line is looped through, hence the third cable. You still have to have a phone somewhere in the system, after all, or there wouldn’t be anything to record…

  3. Bob says:

    It would have to be the phone line back out.
    i.e. Phone cable from street in, phone cable to handset, and RJ45 back to the PC.

  4. Josh says:

    The question is, why not simply use a pci voice modem for the interface, there are certainly enough floating about.

  5. Chris99 says:

    Judging by the component layout (bridge rectifier and transformer), I would say that the RJ-45 is for external power.

    Why run external power when the USB +5V would suffice?

  6. ntietz says:

    The three lines are:
    -phone line in
    -audio output
    -USB output
    These are directly labeled in the schematic which is posted in the .rar file which is available near the bottom.

    @Saydrah: Actually, it does not need a phone out. The way landlines work is such that this would just be sitting connected to one jack, and someone could use another phone in the same house, and it would hear the whole conversation.

  7. trax says:

    hi,
    the cables are:
    RJ45=tapped phone line
    white=audio out, to sound card input
    gray=USB
    and no, you cant use voice modems because they can’t sniff audio from the phone line without “taking the line off-hook” therefore you can’t detect when the line gets free (the modem keeps it occupied, remember?
    also there is a schematic and everything else on the project page, for download

  8. Quin says:

    I do not like being the downer on projects like this, but anyone building and using one should be very careful. Many locales have laws against recording a telephone conversation, even your own, if all parties are not notified. Some even forbid it completely, and count it as wiretapping.

    That said, I love the simplicity of this. It could be simpler, but it is a nice and understandable hack. Kudos to [Trax]

  9. Chris99 says:

    Oh wait. The ‘RJ-11′(?) connector is the line in from the phone. The USB connection to the PIC is via USB to RS232 is only to signal the PC to record the reduced (from 15V-50V to a sound card friendly voltage) analogue signal from the third cord.

    Quite a cool little project.

    I would have used an old MP3 player (with recording capablities), and control it via a PIC in a similar manner. That means the device can be stand alone or connected to the PC via USB when needed.

  10. Pete says:

    People still have landlines?

  11. MReb says:

    Check your state laws, not all states are 1 party states. 1 party states only require 1 person (usually 1 doing recording) to know about recording. 2 party states require that if some ones phone conversation is being recorded that both parties know about it. It can be a criminal offense.

  12. trax says:

    that’s correct. with an old mp3 player you wouldn’t need the PL-2303 usb-serial chip. it is pretty easy to “push” those buttons on a mp3 player with a PIC. now that version would be really mobile :)

  13. peptidefarmer says:

    I second [Quin]‘s post. Please be aware of your local laws before recording telephone conversations. Several states have laws requiring that BOTH parties consent to being recorded:

    http://en.wikipedia.org/wiki/Telephone_recording_laws#United_States

  14. Tim says:

    People still use PICs?

  15. Sam says:

    That could be another project. A phone recorder that automatically alerts people calling that their conversation is being recorder. Personally I hate phones and wouldn’t shed a tear if people stopped calling me because they didn’t want to be recorded!

  16. Ali Raheem says:

    Information isn’t carried over the USB connection, that simply tells the computer to start recording from the audio out connector.

    That’s what it looks like to me atleast.

  17. trialex says:

    @Ali Raheem – “Information isn’t carried over the USB connection, that simply tells the computer to start recording from the audio out connector.”

    That sure sounds like information to me :-) I’m guessing you meant no audio is carried over the USB connection?

  18. tehgringe says:

    wow – such put downs on phone lines…has no one seen the Matrix, hard lines rock ass…plus I love all the ‘experts’ that crawl out of the woodwork when it comes to doing something illegal (once burnt and all that).

    The 2P rule is easy fixed. When an incoming call is detected set pre-recorded mp3 in ready to play state, when the receiver pickup is detected play mp3 with “this call is being recorded” caveat and proceed with call.

    my work here is done :P

  19. Jimbo says:

    The thing with telephony is the need to provide proper isolation (at least 1kV from memory) from between the line and “appliance”, in this case the computer using the appropriately rated line transformer and PCB isolation techniques.

    If you want a handset or line recorder that actually sends the sound over USB as well have a look here:

    http://www.trillium.com.au/modules/mastop_publish/?tac=4

  20. ThatGuy says:

    So many people moaning about this and hardlines. There is a reason this has been made; it caters to the user. *nic phones are easy to record with abit of knowledge or just reading the manual. So writing about that would just be pointless. In fact for my work phone all i have to do is push a button and the server records it, lame encodes it and emails it to me…all out of the box

  21. DanAdamKOF says:

    Have none of you ever done phreaking before?

    This is a nice hack.

  22. barry99705 says:

    @DanAdamKOF Half the people posting aren’t old enough to know what that means.

  23. I been asked about this some time back, by a company that had a need to record in a simple way what going on ones they makes deal buy phone, perhaps somebody know a “turn key” solution ?

    Regards

  24. Loren says:

    @Richard Nibbler – In what way does it look like crap?

  25. trax says:

    @Richard Nibbler – but there are two LEDs in this device, how come you don’t like it? :-)

  26. D. Byrne says:

    We got computers
    we’re tapping phone lines
    I know that ain’t allowed
    da da dah da da….

  27. walter delbono says:
  28. walter delbono says:

    this is part of the circuit…

    the complete hardware and software description is in the main site…

    you got to download it from there at the end of the article there’s a red button for download…

    :)

  29. Whatnot says:

    James bond? Paranoid? How about every person in the western world, who all at least one time got shafted by promises by customer service over a phone that they would correct/do something and then found it was just forgotten/ignored, sometimes leading to large bills and disconnection from various services and legal issues.

  30. Agent420 says:

    Landlines (pots) may be going away, but I can count on one hand how many times I ever picked up a handset and failed to get a dialtone. Compare that to how many times cellular services fail to complete or drop a call.

  31. Agent420 says:

    Fwiw, here’s a table identifying us regulations for phone recording by state:

    http://www.callcorder.com/phone-recording-law-america.htm#State%20Laws%20(Table)

  32. Agent420 says:

    Regarding the off-hook usb circuit and code that is constantly polling the status, you could also use the pinchanged event on one of the status pins of a common serial port… I use the ring indictator for simpile input monitoring quite frequently – works great and doesn’t require usb overhead or a program polling loop.

  33. strider_mt2k says:

    Shitcan the nibbler troll

  34. trax says:

    @Agent420 – At the same time I am using USB to power the circuit (5V). And laptops don’t have serial ports any more… I could have used the LPT but they also are missing from laptops…
    This could have been done much simpler by using the V-USB library and a small ATtiny…

  35. Agent420 says:

    Point taken. Though I have incorporated usb serial converter boards right into some projects, so I get both worlds.

    Nonetheless, good project.

    It would be interesting to look into making this standalone using one of those voice recorder chips.

  36. Dosbomber says:

    I haven’t scoured the ‘net, but the voice recorder chips I’ve seen only have a maximum capacity of a few seconds to a few minutes at best. Kinda useless to record an actual telephone conversation, or do you have no women in your family? ;)

  37. Ali Raheem says:

    @trialex, right you are :)

  38. dex says:

    Excellent stuff! Thanks guys! Some good ideas and a useful project for any phreaks or paranoids out there! xD

    Should name it a coloured box

  39. DanAdamKOF says:

    According to this it’s probably a Tan Box, or a Slug Box: http://www.aboutphone.info/lib/phreak/boxes-2.html

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