[VoIP] Asterisk and Payphones

Sun Aug 5 10:38:39 CDT 2007

Jayson,

The problem of the phone's hanging up preventing coin disposal is easily 
solved.  The coin control adapter you envision can have control over 
supervision towards the FXS or ATA.  If so, even if the telephone goes 
on hook the coin control adapter can keep the FXS or ATA off hook until 
it receives the coin disposal tone and executes it.

Steph

Jayson Smith wrote:
> Hi,
> Actually, I'd originally come up with a different approach for handling coin
> collect and return. The approach I'd thought of, as well as others, I think,
> was using the bluebox/greenbox tones to signal a box which sat between
> Asterisk and a coin phone. The problem with this approach is that if the
> coin phone hangs up, Asterisk is never going to get to send the appropriate
> tone down the line, so the coin(s) will just sit there in the holding
> chamber or whatever the technical term is, until another call is made.
>      Would this circuit work with an ATA, or just with an FXS card from the
> Asterisk box, or either way? The way I'm seeing this, the computer has a
> connection into a box. The box has two phone connections. One goes to a
> source of phone service, be it an FXS port, an ATA, or whatever. The other
> goes into a coin phone.
>      Assuming this project gets completed, or at least in a workable state,
> I might have to think about seriously looking for coin phones. I've always
> been afraid, if I actually bought one on eBay, that the seller would ask all
> sorts of questions like, "What do you want this for? You want to have a
> payphone in your home? Don't you know that under federal law number
> 1234-56789-x3-qrj49, paragraph 29, subparagraph 4C, subsection 21J, it is
> illegal to have a working payphone in your home, with the minimum penalty
> being fifty years sitting in one room and listening to the same telephone
> recording again and again and again?" Ok that got a bit crazy, but until
> now, the only type of payphone which would have even been useful to me as a
> working payphone would be a COCOT. I assume those phones you see on eBay,
> converted for home use, no coins needed, any coins deposited go straight
> into the coin box, have had all their coin guts ripped out so as not to be
> convertible into a working payphone again?
>      On another subject, does anybody have a full set of ACTS recordings, or
> were you figuring on having Allison record some things, or what?
> Jayson
>
> ----- Original Message ----- 
> From: "Lee Spenadel" <lee at spenadel.com>
> To: "'Voice Over IP Tandem for Analog Switches'" <voip at ckts.info>
> Sent: Tuesday, July 31, 2007 8:29 AM
> Subject: Re: [VoIP] Asterisk and Payphones
>
>
>   
>> Mark,
>>
>> My BSP for the 1D/2D Coin Telephone Set shows:
>>
>> Operate Current: 41 mA
>> Non-Operate Current 30 mA
>> Operate Time of 450  +/- 50 ms
>>
>> Lee
>>
>> -----Original Message-----
>> From: voip-bounces at ckts.info [mailto:voip-bounces at ckts.info] On Behalf Of
>> Mark Rudholm
>> Sent: Tuesday, July 31, 2007 1:16 AM
>> To: Voice Over IP Tandem for Analog Switches
>> Subject: Re: [VoIP] Asterisk and Payphones
>>
>> Well, I'm glad to hear there is significant interest in this.
>>
>> For the moment, I'm working on coin-relay control.  My first
>> draft of the schematic is available here:
>> http://rudholm.com/coin-control.pdf (use "File, Rotate" to
>> fix the orientation in Acrobat Reader).
>>
>> My idea is just to take two TTL lines from the computer, either
>> from the parallel port or from a USB to parallel adapter
>> (like the Elexol USBMOD4), one for return vs. collect and
>> the other as a strobe to trigger the relay.  If I use the
>> parallel port, I'll need to add a +5VDC power supply to my
>> interface box to power a TTL buffer since parallel ports
>> can't source or sink enough current to safely drive those
>> solid-state relays.  The Elexol interfaces can source enough
>> current to operate them however, and also since USB ports
>> have a nice 500mA +5VDC supply line, I could throw in a
>> buffer as well.
>>
>> I'll build the circuit described in that schematic on a
>> proto board as soon as my Mouser order for the parts arrives.
>> Once I get it working right and get the relay timing right,
>> then I'll start thinking about the TTL control lines.
>>
>> Speaking of which, if someone could look up in their Coin
>> Crafts or Coin Services Manual Volume I what the coin relay
>> timing is, I need that information.  I'm guessing it's
>> about 500ms but would like verification.
>>
>> Once the hardware is done, it shouldn't be too hard to
>> do a simple return or collect from Asterisk based on whether
>> the call supervised or not.
>>
>> Mark Spencer pointed out to me that DTMF detection is
>> actually not done in zaptel but in a simple goertzel analysis
>> in dsp.c, which makes sense for DTMF decoding.  He suggested
>> I just add a new column and row for 1700 and 2200Hz coin
>> tone.  I figure I'll start hacking the code once I get the
>> hardware working.  I would ultimately like to be able to
>> fully emulate ACTS.
>>
>> I would eventually like to add the Stuck Coin, Coin
>> Presence, and initial rate deposit tests to the system.
>>
>> Support for coin first phones would be nice, but I need
>> to get my hands on the Coin Services Manual to even start
>> thinking about how I'd support all these functions.
>>
>> Three-slot support would be interesting.  I understand the
>> coin bells are tuned so it shouldn't be too hard to
>> add the two tones to the goertzel analysis (one for the
>> nickel/dime bell, and one for the quarter gong).
>>
>> My ultimate goal would be to publish a patch set for the
>> relevant files in asterisk and a schematic and Mouser
>> part number list.  The circuit is too simple to really
>> justify custom printed circuit board artwork (it someone
>> wanted to do that, that'd be fine with me, though).
>>
>> -Mark
>>
>> Greg Blakely wrote:
>>     
>>> I don't know if you'd be able to include a 3-slot patch in the project,
>>>       
>> but
>>     
>>> my payphone is a pre-pay 3-slot Automatic Electric.  It has the "ding"
>>>       
>> bell
>>     
>>> for nickels and dimes, but using a "gong" for a quarter.
>>>       
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