PI based answering machine

[cinetron]

I'm thinking of building a PI based telephone answering machine to cut my teeth on the Raspberry PI. Thinking of using a USB based voice modem and something like vgetty . Does anyone have any advice on this such as recommendations of a voice modem that would work. Thanks

[tzj]

I wouldn"t mind a call blocker, with every known number stored on the pi and unknown numbers are then rejected, kinda like an updatable inline filter.

[walney]

cinetron said:


I'm thinking of building a PI based telephone answering machine to cut my teeth on the Raspberry PI. Thinking of using a USB based voice modem and something like vgetty . Does anyone have any advice on this such as recommendations of a voice modem that would work. Thanks


If you have a look in AT +V or #V command reference documentation for Conexant-based modems the relevant commands are listed. If you go with a hardware serial-port modem rather than a winmodem then you shouldn't have any compatibility/driver issues, since you can just drive them with AT commands (but you will need a serial port). Have a look at the docs for Multitech MT5600ZDX or MT5656ZDX – they even have some examples. You will need a serial port for the pi though. The Zoom 3095 is a USB modem that might work, but that really depends on driver compatibility (I have one, so I am going to test it with a pi …sometime )

Edit: Look at p.28-29 of http://www.multitech.com/en_US.....00098C.pdf

...and in the past I've managed pick them up for £0.99 off ebay

[gjs]

Is this project practical?  Can anyone link to any other examples of a home brew PC based answering machine?

If a modem is connected by serial port to the RPI, won't it also need a USB sound card for recording and playback?

[kasperl]

I know this can work, a friend of mine had a Linux box running a answering machine, that even had a numbered menu system for a while.

[tzj]

an example of numbering software would be awesome

[MegaGumbo]

There is an open source project called "Asterisk" that might be worth to have a look at. It will not only provide an answering machine but also allows complex telephony setups as well. There are even some commercial appliances on the market that are based on Asterisk. A howto for setting up an answering machine with that software is also available on the web.

[gjs]

Asterisk is a VoIP PBX, it's a bit over kill for an answering machine, I would say.  Also, I doubt it will support a voice modem.

[MegaGumbo]

gjs said:


Asterisk is a VoIP PBX, it's a bit over kill for an answering machine, I would say.  Also, I doubt it will support a voice modem.


Just making a suggestion. Regarding voice modem support: that seems to depend on the hardware (http://www.velocityreviews.com.....cards.html). But you're right about the complexity. For a simple answering machine, vgetty will probalby do the job quite well.

[walney]

gjs said:


Is this project practical?  Can anyone link to any other examples of a home brew PC based answering machine?

If a modem is connected by serial port to the RPI, won't it also need a USB sound card for recording and playback?



Yes, it's practical. No sound card needed to record. Using a hardware modem, the modem itself has a DSP which converts the incoming data to (usually) a PCM data stream. You just read the bytes out of the serial port and save them to file. The pi supports audio playback natively.

[ukscone]

The first computer based answering machine I ever heard was when ringing a friend at Cambridge Uni who wrote the ROMs for the Camputers Lynx (Davis Janson). The first one he built using a Tandy TRS-80 Model3 and then a couple of years later he replaced that with one based on the Camputers Lynx. It was a real heath robinson affair with robot arms and tape recorders and actually answered the phone manually but it was damn cool.

Obviously the raspi could forgo the mechanical parts as technology has progressed since the mid 80s but it'd be nice to see someone make a "manual" answering machine based on a Raspberry Pi

[cinetron]

Thanks everyone for your suggestions. I have looked at Asterisk. I thought that would be fun to install but it doesn't support a voice modem as some of you suspected. Still thinking if I can find a usb voice modem supported by ARM it should be fairly straightforward using vgetty.

[gjs]

Please let us know if you find a voice modem that works (I will do the same).  There's lots of other interesting projects I can think of that need a modem/voice modem e.g. text-to-speech dialler, telemarketing blocker, fixed line sms modem, VoIP/POTS gateway, touch tone remote control, caller ID anouncer etc. etc.

[jon0881]

Hi,

Asterisk works with sipura gateways for fxo and fxs connectivity. One of my RPI will be running asterisk with the sipura running the line and handsets. it will do voicemail, voicemail to email, call filtering. Loads of stuff

Regards

Jon

[Docteh]

I have done the vgetty answering machine thing with two USR external modems, the modem would encode into gsm (cant recall if same .gsm as asterisk)
Works quite reliably when it works. I"m not sure why, but one of the modems liked to corrupt the data going to the computer every once in awhile so I would get messages cut off.
33.6 modem worked fine, but the 56k from when 56k just came out was doing it to me. I ended up replacing the 56k modem with an SPA3102 (sipura type device) and asterisk.
Personally i had put off buying a sipura device because i was worried that I couldn"t run it paralell with my other analog phones. Everything I had read seem to state that you have to run the line into the device, and then the other phones on the other side of the device. I wanted to use it in a corner just like regular answering machine. You can. Only a few quirks, I dont think you can tell the SPA deviced to just pick up the phone to join in a call via a voip phone.

[guiseppi]

For the Caller ID based call blocking, also known as telemarketing or junk call blocking, the program called jcblock (Junk Call Blocker) compiles and works on the Pi with a bit of code modification probably required so your modem hangs up properly. I had to add a routine to allow sending commands to the modem without expecting a timely response (+++) otherwise it would hang after a call, and set a jumper to hang up on escape before it worked at all, but ymmv. You should find the jcblock code quite easily. Read the code remarks carefully and probably change the makefile and remove the defines for unrequired features. I removed all three.
I attach my modified jcblock.c and makefile. Hope this is OK.
Like I say, the only problem I had with the code was to answer and hang up the modem reliably, so search "+++"... Some additional libs may be needed, this is all explained in the readme.

[guiseppi]

Sorry. I should have made it more clear that my attachment is not the complete code package, just the main program files. Here's the link to the sourceforge project:

http://sourceforge.net/projects/jcblock/

I have tested the modified code for just over a day now with a headless setup running a tightvnc server, my modem is a US Robotics connected via a USB -> serial connector, which uses the AT#CID=1 command to set Caller ID and hangs up when receiving the escape +++ sequence.
Took me a looong time to figure this all out, mainly down to some infuriating problems with corrupting SD card file systems. Only Raspian and Puppi builds worked reliably for me, the others would boot a few times then be fuxxored
My main reason for buying the PI was to connect to a modem as an advanced call blocker to save the energy of having a PC left on, and at last it works.

[xtalker]

This is a lot more than a answering machine but a worthy link for this thread!

http://hackaday.com/2012/08/22/building ... pberry-pi/

[Maine_guy]

cinetron said:


I'm thinking of building a PI based telephone answering machine to cut my teeth on the Raspberry PI. Thinking of using a USB based voice modem and something like vgetty . Does anyone have any advice on this such as recommendations of a voice modem that would work. Thanks


If you have a look in AT +V or #V command reference documentation for Conexant-based modems the relevant commands are listed. If you go with a hardware serial-port modem rather than a winmodem then you shouldn't have any compatibility/driver issues, since you can just drive them with AT commands (but you will need a serial port). Have a look at the docs for Multitech MT5600ZDX or MT5656ZDX – they even have some examples. You will need a serial port for the pi though. The Zoom 3095 is a USB modem that might work, but that really depends on driver compatibility (I have one, so I am going to test it with a pi …sometime )

Edit: Look at p.28-29 of http://www.multitech.com/en_US.....00098C.pdf

...and in the past I've managed pick them up for £0.99 off ebay

I can confirm that the Zoom 3095 works with Ubuntu with no drivers required. I have been using one with a desktop Linux box for over a year. With Caller ID I turn on the modem signal for non-white listed numbers, and for people on the white-list I turn off auto-answer so my regular answering machine picks up. I haven't dealt with the voice part yet or tried it with a RPi but I will soon. I also use espeak to announce the caller name for those occasions when I'm home when the phone rings.

[xrayted]

Did this project ever happen? I was looking for the same thing in order to have a low power consumption, low heat load, small footprint network attached answering machine for a POT (Plain Old Telephone) - NO voip! - which could save messages to a NAS drive and be managed via browser from my pc. It seems the Pi would be compact enough the project could even be housed in an old answering machine case. (ie. I don't expect to playback from the PI but from something on my net - pc or maybe even phone or tablet.)

I've never worked with a PI or LINUX but have been pretty good with PCs since CP/M. I wasn't sure the PI would have enough horsepower for this task.

Thanks

[Tarcas]

It seems the Pi would be compact enough the project could even be housed in an old answering machine case. (ie. I don't expect to playback from the PI but from something on my net - pc or maybe even phone or tablet.)

Sorry, don't know anything about the status of this project, but the Pi could play back, if you want. Connect buttons to the GPIO and use a script to monitor them and fire off whatever functions they represent. Use a speaker like this one which will also fit in the answering machine case.

[rdibened]

For the Caller ID based call blocking, also known as telemarketing or junk call blocking, the program called jcblock (Junk Call Blocker) compiles and works on the Pi with a bit of code modification probably required so your modem hangs up properly. I had to add a routine to allow sending commands to the modem without expecting a timely response (+++) otherwise it would hang after a call, and set a jumper to hang up on escape before it worked at all, but ymmv. You should find the jcblock code quite easily. Read the code remarks carefully and probably change the makefile and remove the defines for unrequired features. I removed all three.
I attach my modified jcblock.c and makefile. Hope this is OK.
Like I say, the only problem I had with the code was to answer and hang up the modem reliably, so search "+++"... Some additional libs may be needed, this is all explained in the readme.

I am going to give your modified code a try. I have been using Jcblock for a year now on my RPI with no problems, except the option in the code that allows someone to add a number to the blacklist via the telephone didn't work because the ALSA software doesn't see the modem as a PCM device. I hope your code corrects this.

[SaberCat]

I thought I would give an update on the jcblock program (I am the author of it). Recently I posted a separate version for the ATian modem (~$14 Amazon.com), since there were a fair number of code changes. The version is called jcblockAT. It is available at SourceForge at the jcblock site. The important advantage is that the voice AT commands allow the modem to report touchtone key entries. This feature is used by the program to detect a *-key press. When that key is pressed, the program automatically places an entry in the blacklist for the call. So the user does not need to manually add an entry. The first photo at the site shows the hardware. Functionally, it takes the place of the much more complex USR5686G system shown in the second photo and provides error-free *-key operation. I have been running it for over a month now with no problems. As always, there may be issues when it is run with non-US phone systems...

[meingraham]

I ran across this article today - https://www-digitaltrends-com.cdn.amppr ... calls/amp/

Most strategies as to use a do not call registry, NomoRobo, smartphone number blocking lists, or even a Raspberry Pi. I use the first three already, but occasionally, one gets through... and they usually come in batches. The idea is to use the RPi answering machine to pick up these unrecognized numbers and play a "number out of service" (e.g., www.youtube.com/watch?v=2BVbyCZXc5s) recording instead. I can think of nothing quicker to get a telemarketer to stop calling than to reach a number that is no longer in service. And, knowing that these databases are sold, eventually, perhaps, my number would show up as disconnected in those databases altogether.

So, to have a slimmed down answering machine with this outgoing message so that when I see a call I don't want, I trigger the Pi (e.g., via an MQTT topic publish) to answer the call. Otherwise the Pi doesn't pick up. This rather than finding the recorder (as suggested in the article) and potentially having background noise.