Ckt to answer telephone
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Posts: 46,084
Hi. Well I have my stamp hearing DTMF tones, and evrything from that
point on is great. Now, i have a question about the pre-stamp part:
Can anyone point me to a resource that will show how an answering
machine works? I understand that the voltage on the line changes
when the phone "rings", and so on and so forth... I want to be able
to call my stamp, have the stamp answer (ideally after some number of
rings, but instantly is ok).
I'm about to go find an old answering machine to disect, but in the
meantime I was hoping someone here might have some experience with
phone stuff.
TIA!
chris
point on is great. Now, i have a question about the pre-stamp part:
Can anyone point me to a resource that will show how an answering
machine works? I understand that the voltage on the line changes
when the phone "rings", and so on and so forth... I want to be able
to call my stamp, have the stamp answer (ideally after some number of
rings, but instantly is ok).
I'm about to go find an old answering machine to disect, but in the
meantime I was hoping someone here might have some experience with
phone stuff.
TIA!
chris
Comments
Original Message
From: "iamlevis2" <iamlevis2@y...>
To: <basicstamps@yahoogroups.com>
Sent: May 14, 2003 10:12 AM
Subject: [noparse][[/noparse]basicstamps] Ckt to answer telephone
> Hi. Well I have my stamp hearing DTMF tones, and evrything from that
> point on is great. Now, i have a question about the pre-stamp part:
>
> Can anyone point me to a resource that will show how an answering
> machine works? I understand that the voltage on the line changes
> when the phone "rings", and so on and so forth... I want to be able
> to call my stamp, have the stamp answer (ideally after some number of
> rings, but instantly is ok).
>
> I'm about to go find an old answering machine to disect, but in the
> meantime I was hoping someone here might have some experience with
> phone stuff.
>
> TIA!
> chris
>
>
> To UNSUBSCRIBE, just send mail to:
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>
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>
>
[noparse][[/noparse]Non-text portions of this message have been removed]
You set it up to 'auto-answer', and raise a line
on the BS2 when it has connected. I believe you
can send DTMF tones down the line (with 'dial'
commands). Now the only issue is: how do you
connect the stamp line so it 'hears' the DTMF
coming back from you?
--- In basicstamps@yahoogroups.com, "iamlevis2" <iamlevis2@y...>
wrote:
> Hi. Well I have my stamp hearing DTMF tones, and evrything from
that
> point on is great. Now, i have a question about the pre-stamp part:
>
> Can anyone point me to a resource that will show how an answering
> machine works? I understand that the voltage on the line changes
> when the phone "rings", and so on and so forth... I want to be
able
> to call my stamp, have the stamp answer (ideally after some number
of
> rings, but instantly is ok).
>
> I'm about to go find an old answering machine to disect, but in the
> meantime I was hoping someone here might have some experience with
> phone stuff.
>
> TIA!
> chris
you are supposed to do it via a DAA (Data Access Arrangement) - a device to
protect the phone line from your device. I don't know if you still get them
from the phone company or not.
However, if you are going to connect to the phone line, you need to be
careful. When the phone line is idle ("on hook"), the phone line voltage
will be around 48 volts DC. You can't draw any amount of current from it in
this state - I think the load is supposed to be around 10 megohms or so.
When the phone rings, there will be an AC voltage - around 90 volts or so,
as I recall - I forget the frequency, but is relatively low - 100 hz or
thereabouts.
In order to detect a ring, you need to use a full wave bridge rectifier,
isolated from the line via a capacitor. You can filter it, and use a
voltage divider to drop the DC voltage down to 5 volts for the PIC input pin.
To answer the phone, you need to put a load across the line - I've used
600-900 ohms before.
I expect if you do a Google search, you will find a lot of info about this.
At 05:12 PM 5/14/2003 +0000, you wrote:
>Hi. Well I have my stamp hearing DTMF tones, and evrything from that
>point on is great. Now, i have a question about the pre-stamp part:
>
>Can anyone point me to a resource that will show how an answering
>machine works? I understand that the voltage on the line changes
>when the phone "rings", and so on and so forth... I want to be able
>to call my stamp, have the stamp answer (ideally after some number of
>rings, but instantly is ok).
>
>I'm about to go find an old answering machine to disect, but in the
>meantime I was hoping someone here might have some experience with
>phone stuff.
>
>TIA!
>chris
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Larry Bradley
Orleans (Ottawa), Ontario, CANADA
[noparse][[/noparse]Non-text portions of this message have been removed]
phone line and use a phototransistor tied to the Stamp pin to sense when the
bulb is lit. The neon bulb will flash when the phone rings (although it may
blip every once and a while when the phone is picked up or hung up).
Original Message
> Hi. Well I have my stamp hearing DTMF tones, and evrything from that
> point on is great. Now, i have a question about the pre-stamp part:
>
> Can anyone point me to a resource that will show how an answering
> machine works? I understand that the voltage on the line changes
> when the phone "rings", and so on and so forth... I want to be able
> to call my stamp, have the stamp answer (ideally after some number of
> rings, but instantly is ok).
>
> I'm about to go find an old answering machine to disect, but in the
> meantime I was hoping someone here might have some experience with
> phone stuff.
generator, i've confirmed that the stamp now knows when i push a
button, and what button was pushed (thanks to the help of the list).
this is all gonna get stuffed into a little box. no pc, just power
and phone. so:
1) phone rings
2) stamp counts rings
3) when (eg) rings=3, whatever stuff has to be done will take
the "virtual-phone" off-hook
4) the stamp listens to the tones i push, and does stuff
... something something.
--- In basicstamps@yahoogroups.com, "Allan Lane" <allan.lane@h...>
wrote:
> Yes, a standard Modem does this.
> You set it up to 'auto-answer', and raise a line
> on the BS2 when it has connected. I believe you
> can send DTMF tones down the line (with 'dial'
> commands). Now the only issue is: how do you
> connect the stamp line so it 'hears' the DTMF
> coming back from you?
>
> --- In basicstamps@yahoogroups.com, "iamlevis2" <iamlevis2@y...>
> wrote:
> > Hi. Well I have my stamp hearing DTMF tones, and evrything from
> that
> > point on is great. Now, i have a question about the pre-stamp
part:
> >
> > Can anyone point me to a resource that will show how an answering
> > machine works? I understand that the voltage on the line changes
> > when the phone "rings", and so on and so forth... I want to be
> able
> > to call my stamp, have the stamp answer (ideally after some
number
> of
> > rings, but instantly is ok).
> >
> > I'm about to go find an old answering machine to disect, but in
the
> > meantime I was hoping someone here might have some experience
with
> > phone stuff.
> >
> > TIA!
> > chris
http://www.microengineeringlabs.com/downloads/LABXTSCH.PDF
is everything you ever wanted to do with a telephone line and has examples in
PicBasic Pro which are compatible with Stamp BS2
http://www.microengineeringlabs.com/downloads/XTDOCS.ZIP
Original Message
From: "iamlevis2" <iamlevis2@y...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, May 14, 2003 7:32 PM
Subject: [noparse][[/noparse]basicstamps] Re: Ckt to answer telephone
> Well, i have the bs2 hooked up to a dtmf decoder. with a tone
> generator, i've confirmed that the stamp now knows when i push a
> button, and what button was pushed (thanks to the help of the list).
>
> this is all gonna get stuffed into a little box. no pc, just power
> and phone. so:
> 1) phone rings
> 2) stamp counts rings
> 3) when (eg) rings=3, whatever stuff has to be done will take
> the "virtual-phone" off-hook
> 4) the stamp listens to the tones i push, and does stuff
>
> ... something something.
>
>
> --- In basicstamps@yahoogroups.com, "Allan Lane" <allan.lane@h...>
> wrote:
> > Yes, a standard Modem does this.
> > You set it up to 'auto-answer', and raise a line
> > on the BS2 when it has connected. I believe you
> > can send DTMF tones down the line (with 'dial'
> > commands). Now the only issue is: how do you
> > connect the stamp line so it 'hears' the DTMF
> > coming back from you?
> >
> > --- In basicstamps@yahoogroups.com, "iamlevis2" <iamlevis2@y...>
> > wrote:
> > > Hi. Well I have my stamp hearing DTMF tones, and evrything from
> > that
> > > point on is great. Now, i have a question about the pre-stamp
> part:
> > >
> > > Can anyone point me to a resource that will show how an answering
> > > machine works? I understand that the voltage on the line changes
> > > when the phone "rings", and so on and so forth... I want to be
> > able
> > > to call my stamp, have the stamp answer (ideally after some
> number
> > of
> > > rings, but instantly is ok).
> > >
> > > I'm about to go find an old answering machine to disect, but in
> the
> > > meantime I was hoping someone here might have some experience
> with
> > > phone stuff.
> > >
> > > TIA!
> > > chris
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
company has various requirements regarding what
you may attach to their lines -- which a Modem
already has built in.
Note that the Parallax modem board is on sale at
$99.00, and has all the components you need for
direct connection to the phone line already
put together.
The Phone article recommended in the post shows how you
can then couple your BS2 pin directly to the phone lines,
once the Modem has taken them off-hook, so you can
listen to the DTMF tones with the BS2. It looks like
capacitive coupling, with 0.1 uF 250Volt caps and
250 KOhm resistors is what you need.
I really think the phone line interface, and meeting
the phone company's requirements, is the hardest part
of this project, which the Modem Kit would solve
out of the box.
--- In basicstamps@yahoogroups.com, "iamlevis2" <iamlevis2@y...>
wrote:
> Well, i have the bs2 hooked up to a dtmf decoder. with a tone
> generator, i've confirmed that the stamp now knows when i push a
> button, and what button was pushed (thanks to the help of the list).
>
> this is all gonna get stuffed into a little box. no pc, just power
> and phone. so:
> 1) phone rings
> 2) stamp counts rings
> 3) when (eg) rings=3, whatever stuff has to be done will take
> the "virtual-phone" off-hook
> 4) the stamp listens to the tones i push, and does stuff
>
> ... something something.
>
>
> --- In basicstamps@yahoogroups.com, "Allan Lane" <allan.lane@h...>
> wrote:
> > Yes, a standard Modem does this.
> > You set it up to 'auto-answer', and raise a line
> > on the BS2 when it has connected. I believe you
> > can send DTMF tones down the line (with 'dial'
> > commands). Now the only issue is: how do you
> > connect the stamp line so it 'hears' the DTMF
> > coming back from you?
> >
> > --- In basicstamps@yahoogroups.com, "iamlevis2" <iamlevis2@y...>
> > wrote:
> > > Hi. Well I have my stamp hearing DTMF tones, and evrything
from
> > that
> > > point on is great. Now, i have a question about the pre-stamp
> part:
> > >
> > > Can anyone point me to a resource that will show how an
answering
> > > machine works? I understand that the voltage on the line
changes
> > > when the phone "rings", and so on and so forth... I want to be
> > able
> > > to call my stamp, have the stamp answer (ideally after some
> number
> > of
> > > rings, but instantly is ok).
> > >
> > > I'm about to go find an old answering machine to disect, but in
> the
> > > meantime I was hoping someone here might have some experience
> with
> > > phone stuff.
> > >
> > > TIA!
> > > chris
to do it.
Thanks for the help.
--- In basicstamps@yahoogroups.com, "Allan Lane" <allan.lane@h...>
wrote:
> The reason I recommended a Modem is that the phone
> company has various requirements regarding what
> you may attach to their lines -- which a Modem
> already has built in.
>
> Note that the Parallax modem board is on sale at
> $99.00, and has all the components you need for
> direct connection to the phone line already
> put together.
>
> The Phone article recommended in the post shows how you
> can then couple your BS2 pin directly to the phone lines,
> once the Modem has taken them off-hook, so you can
> listen to the DTMF tones with the BS2. It looks like
> capacitive coupling, with 0.1 uF 250Volt caps and
> 250 KOhm resistors is what you need.
>
> I really think the phone line interface, and meeting
> the phone company's requirements, is the hardest part
> of this project, which the Modem Kit would solve
> out of the box.
>
> --- In basicstamps@yahoogroups.com, "iamlevis2" <iamlevis2@y...>
> wrote:
> > Well, i have the bs2 hooked up to a dtmf decoder. with a tone
> > generator, i've confirmed that the stamp now knows when i push a
> > button, and what button was pushed (thanks to the help of the
list).
> >
> > this is all gonna get stuffed into a little box. no pc, just
power
> > and phone. so:
> > 1) phone rings
> > 2) stamp counts rings
> > 3) when (eg) rings=3, whatever stuff has to be done will take
> > the "virtual-phone" off-hook
> > 4) the stamp listens to the tones i push, and does stuff
> >
> > ... something something.
> >
> >
> > --- In basicstamps@yahoogroups.com, "Allan Lane"
<allan.lane@h...>
> > wrote:
> > > Yes, a standard Modem does this.
> > > You set it up to 'auto-answer', and raise a line
> > > on the BS2 when it has connected. I believe you
> > > can send DTMF tones down the line (with 'dial'
> > > commands). Now the only issue is: how do you
> > > connect the stamp line so it 'hears' the DTMF
> > > coming back from you?
> > >
> > > --- In basicstamps@yahoogroups.com, "iamlevis2"
<iamlevis2@y...>
> > > wrote:
> > > > Hi. Well I have my stamp hearing DTMF tones, and evrything
> from
> > > that
> > > > point on is great. Now, i have a question about the pre-
stamp
> > part:
> > > >
> > > > Can anyone point me to a resource that will show how an
> answering
> > > > machine works? I understand that the voltage on the line
> changes
> > > > when the phone "rings", and so on and so forth... I want to
be
> > > able
> > > > to call my stamp, have the stamp answer (ideally after some
> > number
> > > of
> > > > rings, but instantly is ok).
> > > >
> > > > I'm about to go find an old answering machine to disect, but
in
> > the
> > > > meantime I was hoping someone here might have some experience
> > with
> > > > phone stuff.
> > > >
> > > > TIA!
> > > > chris