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Chat Online with Cordless Phone

buckymatters writes "Christoffer Järnåker has converted an old home phone to be used with Skype, MSN voice chat or other similar software. Using the 'highly scientific method Trial and Error' he uncovered the input and output of the phone, wired it up and began talking 300 meters away from his computer on MSN."

132 comments

  1. Steal the kids' toy...!? by bergeron76 · · Score: 4, Funny

    From the article:

    But hey, I have an old Siemens Gigaset 3010 phone laying around that my children play with ('cause the 2 key was a bit broken), I wonder if I can use that one? So I did.

    You're a bad, bad man.

    --
    Don't think that a small group of dedicated individuals can't change the world. It's the only thing that ever has.
  2. MSN has voice? by uberdave · · Score: 1

    I thought that the guy had come up with some sort of text/speech conversion facility, until I read that MSN has a voice chat capability.

  3. I use my cordless with VOIP, too by artemis67 · · Score: 4, Informative

    ...I just plug it into the back of the VOIP adapter that Vonage sent me.

    1. Re:I use my cordless with VOIP, too by Anonymous Coward · · Score: 1

      Just don't try calling 911 on that.

    2. Re:I use my cordless with VOIP, too by Anonymous Coward · · Score: 2, Informative
      911 on vonage works fine now, you just have to set it up on their website with your physical location...

      but it takes like a day for it to take effect...

    3. Re:I use my cordless with VOIP, too by Rick.C · · Score: 2, Funny
      I just plug it into the back of the VOIP adapter that Vonage sent me.

      Oh, that is soooo much like cheating.

      --
      You were 80% angel, 10% demon. The rest was hard to explain. - Over The Rhine
      "Math in a song is good."-Linford
    4. Re:I use my cordless with VOIP, too by StuffJustHappens · · Score: 1

      I have just bought two Olympia Du@lphone 9211IPs (in the UK) for a trial - they are regular DECT phones with Skype capabilities. You plug the base station into the phone line as normal and also into a PC running Skype, via a USB connector. The phone has an extra 'Skype' button and the LCD display can (allegedly - I haven't even opened the box yet) show you which of your Skype contacts are online. More info here: Dualphone

      --
      --What's this sig thing all about then? Should I have one?
    5. Re:I use my cordless with VOIP, too by IANAAC · · Score: 1
      Just don't try calling 911 on that.

      Uh-huh. You must not keep up on VoIP. Vonage, as well as a few other VoIP providers, do provide this for a fee, much like cell phone companies do.

      Those providers that still don't provide this in the US will be required to within 120 days.

      And if you've been following Skype at all, you know that they will probably wiggle out of that requirement by saying they're not really a telephone replacement. They've already done this in Norway. Norway's trying to do the same thing the US is. Regardless, look at what Skype offers and what pretty much any other VoIP company offers their customers. I don't think they're really up for the competition. Skye's great, but it's just voice chat when you compare it to what most VoIP companies offer.

    6. Re:I use my cordless with VOIP, too by renehollan · · Score: 1
      As others have pointed out, 911 on Vonage "works fine". Well, as long as your physical location does not change.

      E911 is still too much in its infancy for me to trust it with my life, as reassuring as it is to have it. I want backup.

      That means keeping a POTS line that I hardly ever use. There's a hardwired single line phone on each floor of our house on that line (that does not require power to get dialtone -- an increasingly rare thing in these days of phones with integrated digital answering machines).

      I use a two line cordless system, with line 2 on the POTS circuit as well, and line 1 on the VoIP link. The cordless base station is not on a UPS (yet), though it eventually will. I also plan to have the VoIP analog port switch over to the POTS line if ever the data link is lost.

      While I could go "plain vanilla" on the POTS line, I do retain a basic "call anywhere in the U.S. and Canada for $0.10 a minute" plan on it for $4 a month -- just because VoIP might go out doesn't mean that I won't want to make LD calls (and Verizon charges $0.75 a minute for calls from Washington state to Canada without an LD plan). And, with the eventual analog failover, a phone user might not even know that VoIP has "gonee out" and not curtail their LD use. (Hmm, I wonder if the dialtone is programmable on a Sipura 3000 to be able to tell when it fails over...).

      --
      You could've hired me.
  4. Pioneer USB chordless phone (Japan) by blankoboy · · Score: 5, Informative

    Noble effort indeed but here in Japan we Pioneer has a USB Chordless phone that I can use with Skype. Great quality! http://tinyurl.com/9ahkw/ http://tinyurl.com/ckveb/ Are these available in North America/EU? Not sure.

    1. Re:Pioneer USB chordless phone (Japan) by DrunkenTerror · · Score: 1

      Konichiwa!

    2. Re:Pioneer USB chordless phone (Japan) by Anonymous Coward · · Score: 0

      Mod parent down for totally unnecessary use of tinyurl. first link, second link

    3. Re:Pioneer USB chordless phone (Japan) by B747SP · · Score: 1
      We here in Australia has a USB cordless (and chordless!) phone that sounds similar to what you describe. From the link: "This is not a SIP phone - it is a USB audio device with keyboard & custom drivers for Skype"

      It's not DECT, its not SIP, but hey, if it works.

      --
      I find your ideas intriguing and I wish to subscribe to your newsletter.
    4. Re:Pioneer USB chordless phone (Japan) by Anonymous Coward · · Score: 0

      konnichi ha, actually.

    5. Re:Pioneer USB chordless phone (Japan) by nilky · · Score: 1

      I don't want to have anything to do with an instrument that won't play three notes at a time...

      --
      "Dishonesty is one of the ugliest possible human characteristics. Being dishonest and proud about is about the only poss
    6. Re:Pioneer USB chordless phone (Japan) by NemosomeN · · Score: 1

      Are you retarded? "wa ()" when used as a particle is written "ha ()", but "konnichiwa ()" is a word. No particle.

      --
      I hate grammar Nazi's.
  5. Okay, so not 300 feet but ... by 0x000000 · · Score: 3, Informative

    I have a bluetooth headset, i just paired it with my iBook, and now i can walk anywhere within approx. 50 feet and hear my music, or talk in Skype.

    Next up, get Bluetooth 2.0 which has a further reach.

    --
    cat /dev/null > .signature
    1. Re:Okay, so not 300 feet but ... by 0x000000 · · Score: 2, Informative

      What the hell was i thinking? 300 feet? I am from freaking europe and i don't even read the submission properly, let alone the article?

      Someone punish me. 300 meters it is. I get 50 feet with my Bluetooth though, so that still holds.

      --
      cat /dev/null > .signature
    2. Re:Okay, so not 300 feet but ... by kponto · · Score: 1

      Which headset? I've been looking for something for that exact purpose and have yet to find something adequate.

      --
      This too, will end.
    3. Re:Okay, so not 300 feet but ... by jasonwea · · Score: 1

      If anyone works out how to get the answer/hangup button working with Skype on OS X, please do advise :)

  6. You've got to be kidding me... by Che+Guevarra · · Score: 4, Funny

    When the article said "old phone" I pictured one of those 12 pounders from 1976. You know, the black or beige kind that would allow you to unscrew the mouth piece and pull out the unwired (not wireless) audio receiver so you could listen to your parents conversation downstairs without them hearing you while you hid in their bedroom... Imagine my shock when I saw a cordless handheld like the one in my kitchen right now. I'm super old.

    1. Re:You've got to be kidding me... by flood6 · · Score: 1

      I had the same reaction. Check this out.

    2. Re:You've got to be kidding me... by Che+Guevarra · · Score: 2, Funny

      I first realized I was old when I remembered saying those CD drives where extravagant. I ordered my most recent Mac with a DVD burner thinking I would never need it. Now I have a Mac that can boot into YDL and Ubuntu so I think I'm staying young. Damnit, what's this VOIP stuff? Just kidding!

    3. Re:You've got to be kidding me... by Anonymous Coward · · Score: 0

      How about a cellular phone that does morse code?
      http://www.engadget.com/entry/1234000657035633/

      It would be way better if it had a telegraph machine interface though.

    4. Re:You've got to be kidding me... by Anonymous Coward · · Score: 2, Funny
      I'm super old.

      Old? I thought you were dead. Didn't the Bolivians nail you back in '64 or am I missing something?

    5. Re:You've got to be kidding me... by russellh · · Score: 2, Funny

      On the internet, nobody knows you're dead...

      --
      must... stay... awake...
  7. What is sad by Anonymous Coward · · Score: 0

    is that anyone this uber-nerdy surely would have nobody to call to talk to, and of course his parents live right upstairs.

    1. Re:What is sad by Anonymous Coward · · Score: 0

      Oh sure, the usual stereotype of a geek in mom's basement.

      Well buddy, I've got news for you, we don't even *have* a basement.

    2. Re:What is sad by kfg · · Score: 3, Funny

      anyone this uber-nerdy surely would have nobody to call to talk to. . .

      Domino's.

      KFG

    3. Re:What is sad by Anonymous Coward · · Score: 0

      So you live in the attic?

    4. Re:What is sad by Anonymous Coward · · Score: 0

      When I saw your 'tagline' I saw the acronym kfg and instantly realised that it stood for "keep f**king guessing". Congratulating myself on my brilliance I went to check I was right - but I wasn't. It's your handle. Unless your handle was written in anticipation of people inquiring - "what does kfg stand for?", leaving you with a snappy response ...

      THought I'd share!

  8. Re:What I want to know... by kfg · · Score: 0, Offtopic

    . . .what a Swede is doing in the Netherlands...

    Slumming

    KFG

  9. Awesome... well.... not very by guyfromindia · · Score: 2, Informative

    I just bought a VOIP to PSTN box on EBay for approx $50 and am using it to connect a cordless phone with skype.. Works very well.. But, I am not saying what this dude did is not worth it.. I like tinkering with stuff.. but they seldom work after I have torn them apart ;-)

    1. Re:Awesome... well.... not very by Anonymous Coward · · Score: 0

      Like Slashdot? Have KIDS?

      Can you tell what's wrong with this sentance?

    2. Re:Awesome... well.... not very by AussieVamp2 · · Score: 0

      Yeah, its hard to order kids online!

    3. Re:Awesome... well.... not very by Anonymous Coward · · Score: 1, Funny

      You spelt sentence wrong?

  10. Just in case by ian+rogers · · Score: 3, Informative
    1. Re:Just in case by Anonymous Coward · · Score: 0

      MirrorDot

      Site is already slow/down.

  11. I agree by 0x000000 · · Score: 0, Troll

    3 users? The site is already at a crawl, and i doubt that many slashdotters are online, as it is midnight in the most of the US. Maybe california or Washington.

    --
    cat /dev/null > .signature
  12. Asterisk by Anonymous Coward · · Score: 0

    Something that I've been thinking about for a while is how to get my Asterisk server to also handle Skype calls. Anyone got any thoughts on this? The main issue for me is that I can't use a PCI card for FXO or FXS as my Asterisk server runs on a laptop and I use a Sipura 3000 for PSDN access.

    1. Re:Asterisk by DaCool42 · · Score: 1

      You don't. Skype is a proprietary protocol and nobody has reverse engineered it yet. IIRC it also uses a patented compression algorithm.

      --

      ----
      All of whose base are belong to the what-now?
    2. Re:Asterisk by Sjobeck · · Score: 0

      If you have asterisk, which is quite possibly the most incredible piece of software, your problems are trivial, just plug your $20 cordless phone from Target in to an FXS port on your server, & get your friends to either use a softphone or buy an ATA, which you would get them to register to your server, dreamy. Keep fighting the good fight. Peace. Love. Linux.

    3. Re:Asterisk by cbrocious · · Score: 1

      The majority of the Skype protocol has been reverse-engineered. There's a paper on it available at .

      That said, you're correct about it using a patented algorithm for its audio compression. Perhaps they'd be willing to give a Free license to said algorithm... doubtful, but possible.

      --
      Disconnect and self-destruct, one bullet at a time.
    4. Re:Asterisk by bloodbob · · Score: 1

      Umm if its patented then the specification for the compression is public so wheres the problem with reverse engineering it?

    5. Re:Asterisk by Anonymous Coward · · Score: 0, Redundant

      Skype is a proprietary protocol and nobody has reverse engineered it yet.
      You use the API Skype provides.
      Since asterisk is a PBX exchanger the way to deal with skype is simple, you run skype calls though the handy dandy api, and then feed the audio data back into asterisk, where it can then handle the rest of the call routing etc etal.

      Feel lucky they don't have a -1 'wrong' moderation ;)

    6. Re:Asterisk by DaCool42 · · Score: 1

      I wasn't aware of this paper. Looks like someone is gunning for the prize

      --

      ----
      All of whose base are belong to the what-now?
    7. Re:Asterisk by Anonymous Coward · · Score: 1, Insightful
      Skype is a proprietary protocol and nobody has reverse engineered it yet.

      You use the API Skype provides.
      Since asterisk is a PBX exchanger the way to deal with skype is simple, you run skype calls though the handy dandy api, and then feed the audio data back into asterisk, where it can then handle the rest of the call routing etc etal.

      Feel lucky they don't have a -1 'wrong' moderation ;)

      You seem to have entirely misunderstood the post you are replying to. The fact that the proprietary Skype program happens to have an API for dealing with the Skype protocol does not mean that the protocol has been reverse-engineered so that any arbitrary program such as Asterisk can interoperate with it (without necessarily needing Skype itself installed). It is certainly true that you could just use the Skype APIs from Asterisk, but that would still require you to have Skype installed. Thus, the statement that "Skype is a proprietary protocol and nobody has reverse engineered it yet." is still correct.
    8. Re:Asterisk by wronskyMan · · Score: 1

      That's the whole point of patenting it - if you reverse engineer it and indepenently implement it, they can still sue you since the patent covers all uses of the idea (unlike copyrights which generally cover a particular implementation in software). The patent allows them to prevent anyone from using it while not having to worry about secrecy; for example, lock companies have been doing this for years with their high-security locks, patenting the shape of the keyway to prevent others from making key blanks to be used to copy keys.

      --
      --- You shall know the truth, and the truth shall make you mad- Neal (not Cowboy) Boortz
    9. Re:Asterisk by bluGill · · Score: 1

      Get a cheap low power computer with a PCI slot. Some old P2 machine, or better yet a low power mini-itx board. You now have a place for a FXO/FXS card, and can have your laptop connect to that as needed. (Depending on your situation you may want to take the server off of your laptop entirely.

  13. Perhaps one more modification by apathyonline · · Score: 2, Interesting

    Thats really neat! perhaps he can make one more modification to it. Make it so he can use it with any wifi router and then he can make calls from anywhere in the city where there is free wifi! It's almost be like a cell phone, only free.

    --

    Tired of Apathy? http://apathyonline.net
    1. Re:Perhaps one more modification by Anonymous Coward · · Score: 0

      That's like asking someone who barely knows enough to install a car stereo system to build a self steering car.

      BTW: Slashdot requires you to wait 2 minutes between each successful posting of a comment to allow everyone a fair chance at posting a comment.

      It's been 4 minutes since you last successfully posted a comment

    2. Re:Perhaps one more modification by Anonymous Coward · · Score: 0

      First get some knowlegde before posting such shit, dude.

      DECT != WLAN even as they are using the same frequency range, 2.4 GHz.

      If you want this, just get an PDA with WLAN and Bluetooth, pair your favourite Bluetooth headset with the PDA, install your favourite VoIP software on that PDA and use it. That's all what you need.

  14. Re:Shouldn't a real story go here? by Anonymous Coward · · Score: 0

    Yeah, except that he wired it up to MSN. Which probably explains why his site's down.

  15. By Any Other Name by Quirk · · Score: 1
    'Using the highly scientific method Trial and Error'

    While reading K. Popper my then wife asked me what I was studying. I replied that I was studying the hypothetical-deductive method, being a smart assed lawyer she replied: "You mean trail and error." I'm not sure, even now, that in its bare essentials they aren't one in the same.

    --
    "Academicians are more likely to share each other's toothbrush than each other's nomenclature."
    Cohen
  16. Article Text by Anonymous Coward · · Score: 5, Informative

    Cost $0.
    Material used: one wireless phone, and one 3.5mm to 3.5mm plug (cut in half).
    Tools used: screwdriver, knife, soldering iron.

    So, the problem. You have a computer, your friend has a computer, you both have a broadband connection, and you make use of Skype or like the voice chat in MSN or something like this - And - you're sick and tired to sit by the computer all the time when you talk. And you might even sit with one of these ridiculous headset (hmm, yes I also have one) on your head just because the echo cancellation feature isn't that great in reality.

    So, the solution. A year ago or so I tried to connect a professional headset from Plantronics to my computer just because they're so damn good and fit perfect. Well, I did get it to work after having a couple of boxes in-between the computer and the headset, but I was still tied to the computer. Now, I've seen some other devices around that basically give you an handset to connect to the USB port and then you can use that. Well, you're still tied to the computer huh? No fun. Then I read in a local magazine (Veronica magazine here in the Netherlands) about Siemens making a DECT USB adapter so that you can connect your DECT phone to the computer - and I though Wow! that's what I need. Well, 119 for another toy that I'll use like not that often? I don't think so. But hey, I have an old Siemens Gigaset 3010 phone laying around that my children play with ('cause the 2 key was a bit broken), I wonder if I can use that one? So I did.

    The victim

    So, how did I do it? Not that simple at first, but very much simpler at the end. I started with opening the base station (Duh!) to see what chipsets were in it. I was hoping for like an RF part a couple of lines on the circuit board and then a telephone circuit. Tji fick jag! No of course not. As any standard electronics they make use of a whole bunch of circuits, so I started looking up on the internet what they did and again - nothing to be found. Then I decided to make use of the highly scientific method Trial and Error and hoping for a bit of good luck.

    By having the phone off hook I carefully inserted my little screwdriver here and there until a heard a click in the handset. And when I found that click I injected a signal from my MP3 player - and it worked! Then reverse, by blowing in the handsets microphone I used the regular headphone for my MP3 player to see where I could 'hear' the phone. By grounding on wire and using the other as a probe I quickly found the spot next to the first spot.

    Note the red (sound to the phone) and green (sound from the phone) circles on the board.

    Then taking an 3.5mm to 3.5mm plug cut in half connecting L+R and then attaching it or respective place (for in and out) making use of the downside of the RF part as ground plane I ended up with this.

    As you can see I've used an unshielded cable, but it works perfect anyway!

    So how did it work? Outstanding!!! Incoming sound in the handset is perfect. Outgoing sound is a bit on the loud side but that's easy to adjust on the computer. It really feels like you're talking on the phone and I have a 300m radius from the house that I can use. While chatting on MSN! Perfect!!!

    So, what are my tips to you? Do you want to try it, but you don't have an Gigaset 3010? The tips I can give you is the following:

    *

    Look at the picture above and you'll see two big capacitors (silver can with a black line on it) and a voltage controller (black small box with five legs) in the lower right corner. Avoid this area! If you connect your headphones or MP3 player here you will most likely fry them. In any other base station you should find a similar area close to the power input (red on mine).
    *

    Be prepared that if you connect anything in the wrong place, even when trying to figure out where the signals are, you can damage the phone, MP3 player or whatever you connect. That is a -might-, and my experience is that it usually turns out fine

    1. Re:Article Text by Che+Guevarra · · Score: 1

      print.

      {et out my xBox and =noknock it all out and not look ati its purpre -t-fcknITout!]

  17. Or just buy the chat-cord! by Sri+Ramkrishna · · Score: 4, Informative

    If you don't want to do all that, get yourself a chat-cord (http://www.chatcord.com/ and just connect your soundcard to your phone using regular pots line. No need to do any modifications. If you buy it through fwd (fwd.pulver.com) it'll only cost you 19.99 (plus 10 bucks shipping unfortunatly)

    I've been using this product and it rocks. My wife and I were just talking to our relatives and if you're phone has a sattelite the two of you can talk at the same time!

    It comes with free software (on XP) that will allow you to dial a number from the phone as well. Not possible yet in linux, but if you know how to decode the DTMF signals, one could easily write something to do the calling for you through the SKYPE API.

    The quality has been great, and you can also use it for free world dialup or whatever. The only disadvantage is that it's not like a real phone, it won't ring if someone calls you. You have to rely on perhaps your computer ringing through the speakers.

    sri

    1. Re:Or just buy the chat-cord! by po8 · · Score: 2, Informative

      The only disadvantage is that it's not like a real phone, it won't ring if someone calls you.

      That's because a real US POTS line uses a 90VAC ring "signal" (actually provides power for an old mechanical ringer if you have one) and there are a lot of good reasons the Chatcord folks wouldn't want to generate that. Too bad, though.

    2. Re:Or just buy the chat-cord! by Anonymous Coward · · Score: 0

      Just 'ebay' RJ11 to USB http://tinyurl.com/8rmr4

    3. Re:Or just buy the chat-cord! by Ossadagowah · · Score: 1

      The Internet Phone Wizard, available at
      http://www.actiontec.com/products/communications/i pw_usb/index.php
      , works fine for skype-based calls.

      --
      anata sekai o kakumei surush ga nai deshou? Anata no susumu michi wa yoi shite arimasu.
    4. Re:Or just buy the chat-cord! by po8 · · Score: 1

      Yep. Ability to ring the phone would be a key difference between the tiny $20 generic POTS product and the largish-looking $60 apparently-skype-only product :-) :-).

  18. Re:"+3, Troll" is my reward by noidentity · · Score: 2, Interesting

    Dissodance is not permitted!

    Why yes it is. What is also permitted is labeling of each post by the group and filtering based on the label. Perhaps you'd rather Slashdot strip everything from a post but the content, and forbid users from creating an external comment moderation system.

  19. Too complicated? by Anonymous Coward · · Score: 0

    Just wondering, but why couldn't he just splice a telephone cord and plug it into the base instead of getting into the phone itself? Not that what he did wasn't neat, but it seems like it could have been a bit easier.

    1. Re:Too complicated? by uberdave · · Score: 1

      A phone uses only one pair of wires. In order to patch into a sound card, you'll need a pair of wires for the line in, and a pair of wires for the line out.

  20. 300 meters? Bah! How about the other party? by noidentity · · Score: 1

    [...] wired it up and began talking 300 meters away from his computer on MSN.

    Waht, was he talking to his computer 300 meters away, or was he talking to someone hundreds or thousands of miles away?

    1. Re:300 meters? Bah! How about the other party? by Anonymous Coward · · Score: 0
      Phone <--- 300 metres ---> Computer <--- hundreds or thousands of miles ---> Someone else
  21. Re:What I want to know... by Anonymous Coward · · Score: 0

    i saw a man in a kilt on a streetcorner today begging for money. he held up a sign "from scotland, need money". in Canada. i swear to god

  22. Re:"+3, Troll" is my reward by jmulvey · · Score: 1

    FYI... making Slashdot a "slashdot.org" site instead of a "slashdot.com" site (which happened several years ago) is simply another example of this behavior.

  23. What's his secret? by Oriumpor · · Score: 1
    ...if you connect anything in the wrong place... you can damage the phone, MP3 player or whatever you connect. That is a -might-...


    I'd figure any number of different shorts could cause the phone to stop functioning/lose function
  24. Re:"+3, Troll" is my reward by noidentity · · Score: 1

    Neat, I hadn't ever looked at which articles I post to. I doubt it matters since most of my comments are pure junk (moderation gives me feedback on how I'm doing, which so far isn't very good). Sorry for getting under your skin, I just think it's stupid to complain that you're being suppressed by the masses. At some point you have to allow for people's own choice to choose what they read. I've read of a few instances of silent removal of comments by admins, but that this is very rare.

    When I get moderator points I almost always use them to moderate posts up, not down (I know what I think is good, but am conservative in deciding what's bad).

    Regarding the handle, I choose it a long time ago and then didn't use the account for years. I didn't see any easy way to change it without creating a new account.

  25. Re:"+3, Troll" is my reward by BJH · · Score: 1

    WTF are you talking about? /. has always been slashdot.org. The slashdot.com domain was only obtained to stop some idiot picking it up instead.

  26. He should have used DC blocking capacitors.... by Newer+Guy · · Score: 4, Informative

    He should have used DC blocking capacitors to couple audio in and out of the phone. He's lucky he didn't blow out something in either the phone or his computer.

    1. Re:He should have used DC blocking capacitors.... by multipartmixed · · Score: 1

      > He should have used DC blocking capacitors to couple audio in and out of the phone

      Care to provide a ~10-word description for the masses? [e.g. "10pf capacitor in series with signal; bonded grounds"]

      I've always used audio transformers when doing this sort of hack, but then again, my AC theory is pretty much non-existant (damned lousy highschool).

      --

      Do daemons dream of electric sleep()?
    2. Re:He should have used DC blocking capacitors.... by Anonymous Coward · · Score: 2, Informative

      A capacitor blocks DC but allows AC to pass.

      By using a pair of 1uF or larger caps in series with your signal and ground, it prevents any dc from being exchanged between the 2 devices, but it allows the ac to pass.

      In this configuration, the caps are 1st order highpass filter. The smaller the cap the higher the frequncy, or basically less bass.

      moddaudio.com

    3. Re:He should have used DC blocking capacitors.... by multipartmixed · · Score: 1

      Did you mean in series with the signal, or in parallel with your signal and ground?

      Also, if electrolytics are used, and you meant in series with the signal, does the polarity of the cap matter?

      Thanks.

      --

      Do daemons dream of electric sleep()?
    4. Re:He should have used DC blocking capacitors.... by Anonymous Coward · · Score: 1, Informative

      in series

      in ---||--- out

      gnd---||--- gnd

      don't use polarized caps

  27. Re:"+3, Troll" is my reward by jmulvey · · Score: 1

    Wrong. There was a time when going to "slashdot.com" would not redirect you to "slashdot.org".

    The "slashdot.org" gives the site the feel of an innocent bystander. In fact, the site is a corporate site, run by corporate interests.

    What story would you post if Microsoft suddenly changed their domain presence from "microsoft.com" to "microsoft.org" ???

  28. Question by Helpadingoatemybaby · · Score: 1
    I've got a question -- why can't he just clip off the plug end of an old phone cord, pick the two center wires and then just plug that in to the socket on his cordless base station and use those to feed the voice signal in just as if it were coming direct from the line? Not trolling, this is a serious question. Perhaps it wouldn't work for some odd reason.

    I remember in the old days I used a tape record on a phone line somewhat like that and it was even good enough to record the 300 baud line connection. I could even play it back and reproduce the text transmitted. That was when I was a rotten kid and ... errr... experimenting.

    --

    The baby's fine -- please stop sending business cards.

    1. Re:Question by DaCool42 · · Score: 1

      He wants in and out. In order to get that on a POTS (standard phone line) connection you need a circuit (known as a "hybrid") to separate the local and caller audio (they are mixed together). Rather than go to the work of building or buying a circuit, he is using the phone base's existing circuit to do it for him.

      --

      ----
      All of whose base are belong to the what-now?
    2. Re:Question by mrgreen4242 · · Score: 1

      Hm, are you sure about that? I'm pretty certain that POTS phone lines have separate trans and receive lines. I used to work for a telecom company, and the signal coming into the telco office is separate. So unless the phone combines the signal and then it is split somewhere before it enters the telephone office there should be a line for Rx, Tx, and a ground wire.

    3. Re:Question by adamjaskie · · Score: 1

      Well, this phone here on my desk only has two wires, so I guess that answers that question.

      --
      /usr/games/fortune
  29. Re:"+3, Troll" is my reward by jmulvey · · Score: 0, Offtopic

    You responded: "Neat, I hadn't ever looked at which articles I post to.".
    My response: What hogwash. We're not that stupid. Is that what you really think someone who isn't playing "monkey business" would have said? Then you say, "I doubt it matters since most of my comments are pure junk"... as the cartoon goes... you just self-deprecated yourself out of a job.

    You responded: "Regarding the handle, I choose it a long time ago and then didn't use the account for years."
    My response: Interesting. Your account has posted at least 24 comments in the last 8 days. Unfortunately (or fortunately, for you) Slashdot doesn't let us go beyond the last 24 comments to validate your statement. How convenient.

    As an aside, you should

  30. Re:"+3, Troll" is my reward by noidentity · · Score: 0, Flamebait

    You're a fucking dumbass (and you even use your karma bonus... lame).

  31. Re:"+3, Troll" is my reward by Anonymous Coward · · Score: 0

    what's the matter? can I help you in some way? have you fallen on your head?

  32. You could just buy one :) by drelectro · · Score: 1
    See the following link for a DECT Cordless phone that has a base station with both a USB connector for Skype calls and a regular PSTN connection.

    You can browse your Skype contact list from the handset too.

    http://www.dualphone.net/

    Skype bashing aside that's still pretty neat!

    1. Re:You could just buy one :) by usheletz · · Score: 1

      acompanying software (usb driver, dialer) is windows only. specs are closed. no other os support is planned. doh!
      that's actually pretty stupid - they specifically market this product for skype users and the later is supported on 3 major platforms.

  33. Translation by DaCool42 · · Score: 4, Funny

    "Christoffer Järnåker, who knows just enough about electronics to be dangerous, has somehow managed to kludge a new-ish cordless POTS phone to be used with *insert popular MS-based proprietary VOIP software*. Using the 'oh jeez I hope I didn't fry my phone, computer, and mp3 player method' he uncovered a spot on the circuit board which didn't immediately destroy everything, soldered three wires, and somehow got on slashdot for it.

    --

    ----
    All of whose base are belong to the what-now?
  34. Re:"+3, Troll" is my reward by Anonymous Coward · · Score: 0

    you've been drinking

  35. Hold on by ramzak2k · · Score: 3, Insightful

    Isnt the article just about providing for a head phone and mic wire from an existing phone?

    It doesnt allow you to punch numbers and call to skype directly.

    Nice hack but the story title is misleading.

    --

    Siggy Say, Siggy Do
  36. Re:"+3, Troll" is my reward by bnitsua · · Score: 1

    you obviously parsed his username incorrectly... it's "noid entity," a reference to the old Domino's Mascot.
    god, you really ARE a dumbass.

  37. First Words... by Zonnald · · Score: 2, Funny

    Finally got it working and said....
    "Mr. Watson come here"

    1. Re:First Words... by ch-chuck · · Score: 1

      Using MSN, it could happen.

      --
      try { do() || do_not(); } catch (JediException err) { yoda(err); }
  38. Why hack it? by Gentlewhisper · · Score: 3, Informative

    Siemens already has a USB attachment that lets you use VoIP (skype) from your Cordless Phone.

    M34 USB

    I'm using it now, and it works really well. One thing about using the hack in the article is your phone won't ring when you get a VoIP call... with the adapter it works just like a normal phone.

    1. Re:Why hack it? by Eunuchswear · · Score: 3, Informative
      From the article:
      Then I read in a local magazine (Veronica magazine here in the Netherlands) about Siemens making a DECT USB adapter so that you can connect your DECT phone to the computer - and I though Wow! that's what I need. Well, €119 for another toy that I'll use like not that often? I don't think so.
      Does that answer your question?
      --
      Watch this Heartland Institute video
  39. Re:What I want to know... by Sjobeck · · Score: 0

    that is terribly funny. thx Peace. Love. Linux.

  40. Re:What I want to know... by Sjobeck · · Score: 0

    like Mike Meyers, one of the funniest people to ever walk the planet, always says (SNL), "if it's not Scottish, it's crap."

    Peace. Love. Linux.

  41. I did just about the same thing by pair-a-noyd · · Score: 4, Interesting

    with a Rolm phone 240. I have quite a few of them so what the hell. Matter of fact, I have a full 12 node Rolm CBX II 9000. And I don't have a POTS line to my name.. Long story..

    Anyway, I took the Rolm phone and on the main board in the base unit I soldered two cables to the connection for the handset and speaker. So the handset runs straight into the soundcard of a machine that does Sykpe.

    When the phone is on hook, the magnet in the handset cause a reed relay to pass audio from the soundcard to the speakerphone speaker in the base unit so you can hear it ring and hear normal sound events through it. When you lift the handset the sound re-routes to the handset and you use it like a normal phone.

    You can't dial from it, none of the buttons or lights work, but the sound quality is excellent and you can rest it on your shoulder because it's a full sized handset, unlike the dinky cell phones of today.

    To use it, you would SWEAR you are talking on a standard POTS phone. My friends are amazed and befuddled by it, so I have been building them for all my friends.

    Next project is to go buy a cheapo cordless, my local grocery has them on the imported crap isle for $14 for a 2.4ghz.. It's probably crap but it's cheap enough to experiment on. I have a $300 Vtech 2 line cordless that I don't want to experiment on, I'll save it for when I get an adapter..

    1. Re:I did just about the same thing by MasTRE · · Score: 1

      > I did just about the same thing with a Rolm phone 240. I have quite a few of them so what the hell. Matter of fact, I have a full 12 node Rolm CBX II 9000.

      Well, aren't you special? :p

      --
      Must-not-watch TV!
  42. Did this before... by cyberpatrol_735 · · Score: 1

    Just turn on voice chat.. stick a phone up to the speakers or wire it, either way, grab a cordless and start talking.. it works. It doesn't take a genious to figure this stuff out.

  43. Re:Translation of the translation by Rick.C · · Score: 2, Funny
    ... "it's better to be be lucky than to be good."

    That's not a theory, you know. That's a friggin' AXIOM.

    --
    You were 80% angel, 10% demon. The rest was hard to explain. - Over The Rhine
    "Math in a song is good."-Linford
  44. Re:"+3, Troll" is my reward by Kalak · · Score: 1

    If MS started as Bill Gate's blog, then I could see ms.org.

    --
    I am, and always will be, an idiot. Karma: Coma (mostly effected by .hack)
  45. Uh? Why go to all this trouble? by windex · · Score: 1

    It actually is possible to extract audio off of a phone line directly, anyway. That's why I don't understand how this is so impressive.

    You just build a special rj11 cable, and done.

    I used the same trick to build a speakerphone into my stereo with a microphone. I didn't even have a normal handset in the loop, just an on/off switch.

    1. Re:Uh? Why go to all this trouble? by MasTRE · · Score: 1

      > It actually is possible to extract audio off of a phone line directly, anyway. That's why I don't understand how this is so impressive.

      Care to explain yourself? The consensus is that the POTS RJ11 only uses 2 wires, and the sound is mixed on them (both in and out, together). You would need some sort of circuit that separates them in order to prepare for use on computer. The phone has his circuit built in, so he spliced himself into that. I guess that's why it's impressive. But if you know a better way, please, by all means -- enlighten us.

      --
      Must-not-watch TV!
    2. Re:Uh? Why go to all this trouble? by windex · · Score: 1

      It's an audio loop -- you run a set of speakers off the 'hot' wire, and a microphone bridged to the negative lead off of an audio cable back into the 'return' wire. You get better results using an amplified source, such as a sound card or stereo with a microphone jack and seperate microphone output. You don't really need a circuit to seperate them so much as you need to match the output level of the microphone to make it audible over the line. This is exactally how old analog phones work, basically. I figured out how to wire this by ripping apart an old 70's ma bell beige telephone. When you lift the receiver, it bridges the hot wired to the speaker and the return wired to the mic, thus completing the circuit.

      If you don't want to hear yourself echo, and you're using a portable phone which provides its own power instead of depending on the line, you can simply hook the hot pin into the speaker line and the return pin into the microphone line. Then use your soundcard's mixer to lower the volume on the speaker and microphone leads, and set up a test call with someone using skype or whatever, and raise the volume levels until the call is clear.

  46. I did this too by enosys · · Score: 2, Interesting

    I also modified a cordless phone for use with online voice conversations. It's a Sanyo CLT-9171, one of the early 900 MHz spread spectrum digital ones. Using an oscilloscope it was easy to find where to connect. The phone still works for standard phone conversations, and I can even use one of the connections I added to record conversations.

    1. Re:I did this too by andrewuoft · · Score: 1

      I have a Sanyo CLT-9819, post diagrams where to hook it up!

    2. Re:I did this too by enosys · · Score: 1
      I just opened up the phone and took a photo. The connection labelled mic is the audio output (connected to computer line in) and spkr is the input (connenected to computer line or headphone out). The connection with two wires connecting to it is ground. Note how I decoupled the mic connection with a 0.1 microfarad capacitor.

      I decided to have short cables dangling out of the phone to avoid doing permanent modifications to the case. I unplug the phone when using the phone with my computer and I unplug the computer connections when using it as a phone. I've also used the "spkr" connection to record phone conversations.

  47. I just used bluetooth by Anonymous Coward · · Score: 0

    Admittedly it is not free but I bought a bluetooth USB Dongle and a bluetooth headset.

    This allows me to be upto 300 meters away and it is completely hands free.

  48. Crap. by IANAAC · · Score: 1

    Sorry 'bout the bold. "ockquote" got lost in it. :-)

  49. Pth, that's nothing by anarkhos · · Score: 1

    I once converted a cordless phone into a wireless internet connection using modems.

    --
    >80 column hard wrapped e-mail is not a sign of intelligent
    >life
  50. Re:Sweet by Anonymous Coward · · Score: 0

    Well, we wouldn't want our Yoda dolls to be cut off from the rest of the world, would we?

  51. Re:What I want to know... by Anonymous Coward · · Score: 0

    They're probably there on vacation from Sweden, where they're "refugees", and we Swedish taxpayers are footing the bill as usual.

    So, how do you like your new multi-criminal society?

  52. Give him a break. by lullabud · · Score: 1

    Come on man, there are g33ks in the country, and lot's of country houses only have one floor, no attic. Give the guy a break he's already been ostricized enough... So he lives on the same floor as his parents. Does that really make him any less g33ky? Who knows? Maybe they're a whole cult of g33ks running around in Star Wars and LARP attire 24/7, like a non-stop Ren Fest. You just have to accept people's differences.

  53. Idea - Using a Voltimeter? by syberdave · · Score: 1

    I'm thinking that a voltimeter would help with the trial and error. Like if you use it to try to find where you can connect the wires. I don't think that would damage anything either.

    Would it work? I don't have much electrical experience so I don't know.

  54. Q: How does full duplex on one circuit work? by A.+Jordan · · Score: 1

    Regarding POTS handsets, how does full duplex on one circuit work?

  55. ha! by Anonymous Coward · · Score: 0

    um... you have a bluetooth headset so you don't have to be too close to your laptop?

    I usually keep my head within a few meters of my lap personally. I guess I don't need bluetooth 2.0 unless I grow to be 7 feet tall?

  56. so what by nuggetman · · Score: 1

    in 1999 when Dialpad was the rage, we went out and bought a telephone handset. It was packaged with a cable that had RJ-11 on one end and mic/speaker miniplugs on the other. What's the big deal here?

    --
    ...and that's all there is to it.