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How to Block Incoming Calls ? — Parallax Forums

How to Block Incoming Calls ?

john_sjohn_s Posts: 369
edited 2014-04-02 08:39 in General Discussion
I have a land-line phone that started being bombarded with unwanted calls from 888, 800, 855 etc numbers and I need to block them all.
I know that amazon and others do carry certain call blocking devices but I'd prefer to enjoy building one using parallax bits and pieces myself.
Let's say that I have most of the components that can be safely attached to the phone line without causing any disruption to the service.
I also have a caller ID enabled.

I envision a contraption having a LCD with a push button that you press to block the unwanted calls when still shown on my caller id display.
Next would be some automated tone generator (dtmf *?) to trick those robots that my line is out of service, and so on...

Any ideas/help?
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Comments

  • FranklinFranklin Posts: 4,747
    edited 2014-03-29 13:28
    It's called the SIT tone, https://www.youtube.com/watch?v=5gw6cR_XTYg I got one here but I don't think they still have them. http://www.sandman.com/taliban.html
  • john_sjohn_s Posts: 369
    edited 2014-03-29 16:15
    SIT tone generator/player is going to be a part of it for sure - but first I need to figure out how to "mute" loud ringing as caller ID message is sent between the first and second ring.
    So at least the first ring tone is going to be heard anyways - or not?
  • kwinnkwinn Posts: 8,697
    edited 2014-03-29 16:22
    john_s wrote: »
    SIT tone generator/player is going to be a part of it for sure - but first I need to figure out how to "mute" loud ringing as caller ID message is sent between the first and second ring.
    So at least the first ring tone is going to be heard anyways - or not?

    The device you build should sit between the incoming line and the phones so it can block the first ring, decode the caller ID, and then either pass the call through, block it, or pick up the line and play the SIT tone.
  • Beau SchwabeBeau Schwabe Posts: 6,566
    edited 2014-03-29 16:59
    Just unplug the phone

    Seriously, I would be surprised if there wasn't a Phone App that allowed you to block your own list of numbers. We did away with our land line a long time ago since essentially it's an IP phone anyway through our cable provider. A Cell is just a wireless IP phone.
  • john_sjohn_s Posts: 369
    edited 2014-03-29 19:56
    kwinn wrote: »
    The device you build should sit between the incoming line and the phones so it can block the first ring, decode the caller ID, and then either pass the call through, block it, or pick up the line and play the SIT tone.

    So is there an easy way to block the first ring before it "rings the bell"?
  • Beau SchwabeBeau Schwabe Posts: 6,566
    edited 2014-03-29 20:17
    "So is there an easy way to block the first ring before it "rings the bell"? " - If you monitor the voltage on the Phone line it will cross the Zero line >> before << the ring voltage is applied.
  • ercoerco Posts: 20,256
    edited 2014-03-29 20:36
    See http://www.thegurureview.net/aroundnet-category/ftc-awards-winners-in-robo-call-blocking-contest.html
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-03-30 07:22
    I just ask the caller if they speak English and they immediately hang up.
  • mindrobotsmindrobots Posts: 6,506
    edited 2014-03-30 07:43
    Loopy Byteloose wrote: »
    I just ask the caller if they speak English and they immediately hang up.

    Haha! That would work in the State if you flipped it around. Just learn a few key phrases in some obscure language (Klingon, anyone) and answer your phone that way - a broken English "Hello" followed by a flurry of some foreign language. What fun!!

    As for the "first ring", if your device is where the line enters your premise, can't you just have it eat the first ring if it needs time to process the CID message? You just need to make sure you don't mess up the "off hook" signalling or you won't be able to make outbound calls because the central office will never see your phone go off hook. Most of these devices I think just passively monitor the line until they see the CID message and then they decide what to do.
  • RDL2004RDL2004 Posts: 2,554
    edited 2014-03-30 09:46
    Does the National Do Not Call Registry not work anymore?

    edit: I just noticed you are not in the U.S., is there anything similar in Canada?
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2014-03-30 10:38
    RDL2004 wrote: »
    Does the National Do Not Call Registry not work anymore?

    Its focus: those out to sell; excepted are charities, survey takers, and collections agents on zombie debt missions (lots of numbers abandoned by deadbeats out there.)
  • John AbshierJohn Abshier Posts: 1,116
    edited 2014-03-30 10:47
    The do not call registry does not work! Nor has a formal complaint to the Kansas Attorney General. Card Services, trying to lower my credit card interest rate, uses many names and phone numbers to try to get you to answer. They are the worst, but not only unwanted phone calls I get. Sadly, once I didn't answer my son's fiancee's call because I didn't recognize her phone number.

    John Abshier
  • PublisonPublison Posts: 12,366
    edited 2014-03-30 11:20
    Not sure anyone noticed, but the OP is out of Canada. Different rule may apply? ( I haven't read through the site yet).

    https://www.lnnte-dncl.gc.ca/index-eng
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-03-30 11:44
    So far it seems that the best you might do is to hire a butler for your home and a secretary for work to screen all calls. We just haven't been able to create a device that will help people avoid annoying and dodgy characters.
  • potatoheadpotatohead Posts: 10,261
    edited 2014-03-30 11:54
    Put a FAX machine on the line for a while. Just set it to auto answer and let it do it's thing. Heck, load it with some great jokes for the odd clown who decides to take the FAX. Amazingly, some will. That was my experience.

    I recommend http://xkcd.com

    These call banks are trained to blueprint their prospects. If they can call you, then you are a prospect! Doesn't matter what. They figure that out after they get a live body on the phone.

    Adding the FAX machine will see "FAX" added to the database and you need to get the heavy hitters to log that FAX machine. Once they do, you won't get calls anymore. Bonus points for when they sell or rent their lists to others.

    Or, if you can whistle something close to the start leader tones and make a "psssssssh" sound reasonably well, that works too. I used to do it on our land line regularly years ago. That was enough! It worked just fine. They only need to hear enough to think it's a FAX and you are good. I suppose a recording would work for this just as well.

    For friends and family, use a ring, hang up, wait, ring system to get them through.

    BTW: Elections coming up. List rentals will be off the charts for a while, as will the politically motivated calls. Great time for a FAX. You can get off of a ton of lists.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-03-30 12:09
    Or you could abandon the land line and just use a cell phone. Never answer the cell phone. Only call back people that SMS you with a request to call.
  • john_sjohn_s Posts: 369
    edited 2014-03-30 13:33
    erco wrote: »
    See http://www.thegurureview.net/aroundnet-category/ftc-awards-winners-in-robo-call-blocking-contest.html

    I was aware of it and did some search on the results http://nakedsecurity.sophos.com/2013/04/04/new-robocall-killer-technologies/

    Anyways, here's a product from UK that looks like they did it already few years before that contest :)

    https://www.youtube.com/watch?v=Ga9Zm_tU15o
  • john_sjohn_s Posts: 369
    edited 2014-03-30 13:48
    Publison wrote: »
    Not sure anyone noticed, but the OP is out of Canada. Different rule may apply? ( I haven't read through the site yet).

    https://www.lnnte-dncl.gc.ca/index-eng

    Yeah, I'm on the list already for 4 years and still getting the annoying calls .
    Seems like the robocalls are the worst abusers and switch their numbers at will so it does not work.
    Also, there is a "procedure" that requires you to fill the very same and lengthy form every time you report another abusive phone number.
    You cannot place more then a SINGLE unwanted ph.number per report.
    You must go through all your name. surname, ph. number, email addr etc details every time over and over again.

    So how can I silent the 1st ring to give me time to analyze first who's calling?
  • FranklinFranklin Posts: 4,747
    edited 2014-03-30 13:52
    http://lifehacker.com/5981063/block-telemarketers-and-robocalls-for-good-with-the-raspberry-pi-powered-banana-phone/all
    https://www.wrbishop.com/telecom/end-robocaller-solicitation-and-hangup-calls-with-asterisk/

    Here are two options, perhaps there is a way to use a propeller chip instead of the RasPi.
  • kwinnkwinn Posts: 8,697
    edited 2014-03-30 16:48
    john_s wrote: »
    So is there an easy way to block the first ring before it "rings the bell"?

    Yes. Use a relay to switch the house phones between the incoming line and the microcontroller.
    The normal position of the relay would isolate the phones from the incoming line.
    The micro monitors both the phones and the incoming line.
    If a phone goes off hook the micro energizes the relay to connect the phone to the line for an outgoing call.
    When a ring tone is detected the micro waits for and decodes the caller ID.
    If this is a call that you want to receive the micro energizes the relay and passes on subsequent rings.
  • kwinnkwinn Posts: 8,697
    edited 2014-03-30 17:01
    Franklin wrote: »
    http://lifehacker.com/5981063/block-telemarketers-and-robocalls-for-good-with-the-raspberry-pi-powered-banana-phone/all
    https://www.wrbishop.com/telecom/end-robocaller-solicitation-and-hangup-calls-with-asterisk/

    Here are two options, perhaps there is a way to use a propeller chip instead of the RasPi.

    The propeller chip could do this. There is a modem object for decoding the caller ID, eeprom and/or sd objects for storing numbers to be blocked and/or allowed through, and tone generation objects for producing the SID tones. Wish the propeller had been around way back when I did this with a Z80.
  • kwinnkwinn Posts: 8,697
    edited 2014-03-30 17:08
    AFAIK the rules are pretty much the same, and our DO NOT CALL list works about as well as the US one.......that is not so much at all. In fact based on what I hear from others it sounds more like a DO CALL list. I solved my problem by going to Vonage for my home phone.
  • john_sjohn_s Posts: 369
    edited 2014-03-30 17:40
    kwinn wrote: »
    Yes. Use a relay to switch the house phones between the incoming line and the microcontroller.
    The normal position of the relay would isolate the phones from the incoming line.
    ....

    Exactly as I thought - when having just a single device I need to place it next to telco entry panel to isolate ALL of my phones.
    Unless I can reduce the very 1st ringing voltage to a bare minimum (and not to raise any suspicion from their office of course) followed by caller ID recognition.

    I am not even sure if it's legal to "crowbar" a ringer ?
  • kwinnkwinn Posts: 8,697
    edited 2014-03-30 17:49
    No need to "crowbar" the ringer. A capacitor in series with a 560 or 680 ohm resistor will simulate the load of a phone being connected to the incoming line. Once the first ring and caller ID have been received the line will either be connected to an actual phone or the SID tone generator by the uP.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-03-31 03:59
    I suppose that the telephone company could provide specific service that sequences the Caller ID first and the right second. They might even make money from it.

    But my impression from a previous thread is that any other way would require you to have a filter that eliminates all first rings from your phones before it gets to the phone. Others above seem to agree.
  • trookstrooks Posts: 228
    edited 2014-03-31 04:53
    If only there was some way to use a Captain Crunch whistle on the jerks.

    I gave up the land line over a decade ago and for the most part I keep my cellphone in a homemade aluminum foil carrying case<G>.

    If the call really matters they know to leave a message and call one of my neighbors to give a prearranged signal so I will check voice mail.


    Jusa Nother GOM,

    Tim
  • Mike GMike G Posts: 2,702
    edited 2014-03-31 05:00
    Have you checked with your land line provider? My service provider has a blacklist option. Enter the annoying phone number in the black list and that about it... no more annoying calls.
  • John AbshierJohn Abshier Posts: 1,116
    edited 2014-03-31 07:38
    Blacklist will not work. Phone spammers change their number regularly.

    John Abshier
  • john_sjohn_s Posts: 369
    edited 2014-03-31 08:05
    kwinn wrote: »
    No need to "crowbar" the ringer. A capacitor in series with a 560 or 680 ohm resistor will simulate the load of a phone being connected to the incoming line. Once the first ring and caller ID have been received the line will either be connected to an actual phone or the SID tone generator by the uP.

    Correct me if I'm wrong - but placing a load and seizing the line immediately (milliseconds?) after sensing the 1st ring will cause the off-hook condition thus preventing the caller-ID to be sensed?
  • john_sjohn_s Posts: 369
    edited 2014-03-31 08:11
    Beau Schwabe (Parallax) wrote: »
    "So is there an easy way to block the first ring before it "rings the bell"? " - If you monitor the voltage on the Phone line it will cross the Zero line >> before << the ring voltage is applied.

    Thanks Beau - this IS the answer that I somehow missed; now I need a "simple" circuit that does it :)
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