Adding a SIP doorbell to Homekit with two-way audio

This example shows how to add SIP audio intercom to Homekit

Used Rasberry Pi 4 with Homebridge image installed

Intercom control is carried out via DTMF commands

• Make changes to the system settings

  24-hour time format
  date format DD/MM/YYYY
  

• Adding the ALSA Loopback Sound Device

  sudo su
  echo 'snd-aloop' >> /etc/modules
  exit
  

• Making changes to the ALSA configuration

  Create or edit the /etc/asound.conf file

  # output device
  pcm.loop_out {
    type dmix
    ipc_key 100001
    slave.pcm "hw:Loopback,0,0"
  }
  
  # input device
  pcm.loop_in {
    type dsnoop
    ipc_key 100002
    slave.pcm "hw:Loopback,1,1"
  }
  
  # plug device
  pcm.sipdoorbell_return {
    type plug
    slave.pcm 'loop_out'
    hint {
      show on
      description 'sipdoorbell return channel'
    }
  }
  
  # plug device
  pcm.sipdoorbell_main {
    type plug
    slave.pcm loop_in
    hint {
      show on
      description 'sipdoorbell main channel'
    }
  }
  

  !!! if you get homebridge error when open doorbell device on iphone/ipad/AppleTV:

  [error] cannot open audio device sipdoorbell_main (No such file or directory)
  [error] sipdoorbell_main: Input/output error
  

  or

  [error] cannot open audio device sipdoorbell_return (No such file or directory)
  [error] sipdoorbell_return: Input/output error
  

  put this code at the end /usr/share/alsa/alsa.conf instead /etc/asound.conf

• Installing baresip

  sudo apt install baresip
  

• Run baresip to create a configuration file, after launch press 'q' to exit

• Making changes to the baresip configuration file: file /home/pi/.baresip/config

  Remove the comment from the following lines and make changes

  sip_listen              0.0.0.0:5060
  
  audio_player            alsa,hw:Loopback,0,1
  audio_source            alsa,hw:Loopback,1,0
  audio_alert             alsa,hw:Loopback,0,1
  
  ausrc_srate             48000
  auplay_srate            48000
  ausrc_channels          2
  auplay_channels         2
  
  module                  httpd.so
  
  http_listen             0.0.0.0:8000
  

• Add a SIP account to the file /home/pi/.baresip/accounts

  • When using P2P SIP call

    When using P2P, the call must be in the format "100 @ <homebridge_ip_address>"

    <sip:100@127.0.0.1>;auth_pass=none;regint=0;
    

  • When using SIP registration

    <sip:extention_number@sip_server_ip>;auth_pass=account_password;
    

• Install the Homebridge Camera FFmpeg plugin

• Add a camera in the Homebridge Camera FFmpeg plugin

  Cameras

  Name: Doorbell
  Video Source: "-re -stream_loop -1 -i /opt/sipdoorbell/homekit.avi -f alsa -ac 2 -ar 48000 -i sipdoorbell_main"
  Still Image Source: "-i /opt/sipdoorbell/homekit.jpg"
  Enable audio: checked
  

  Advanced EXPERIMENTAL - WIP

  Two-way Audio Target (EXPERIMENTAL - WIP): "-f alsa -ac 2 -ar 48000 sipdoorbell_return"
  Two-way FFmpeg Debug Logging: checked
  Audio Stream: "1:a"
  Enable doorbell: checked
  

  Global Automation

  HTTP Port:8080
  

  If there is an RTSP stream from the intercom, replace "-re -stream_loop -1 -i /opt/sipdoorbell/homekit.avi" and
  "Still Image Source: "-i /opt/sipdoorbell/homekit.jpg"" with the link of the RTSP stream

• Homebridge Camera FFmpeg Plugin Configuration

  "source": "-re -stream_loop -1 -i /opt/sipdoorbell/homekit.avi -f alsa -ac 2 -ar 48000 -i sipdoorbell_main",
  "stillImageSource": "-i /opt/sipdoorbell/homekit.jpg",
  "returnAudioTarget": "-f alsa -ac 2 -ar 48000 sipdoorbell_return",
  "mapaudio": "1:a",
  "audio": true,
  "debugReturn": true
  

  If there is an RTSP stream from the intercom, replace "-re -stream_loop -1 -i /opt/sipdoorbell/homekit.avi" and
  "Still Image Source: "-i /opt/sipdoorbell/homekit.jpg"" with the link of the RTSP stream

• Install the Homebridge Http Switch plugin (if nessesary)

• Homebridge Http Switch Plugin Configuration (if nessesary)

  Command for open the door via send HTTP request to Baresip

          {
              "accessory": "HTTP-SWITCH",
              "name": "Open",
              "switchType": "stateless",
              "timeout": 3000,
              "multipleUrlExecutionStrategy": "series",
              "onUrl": [
                  "http://127.0.0.1:8000/?/sndcode 0",
                  "http://127.0.0.1:8000/?/sndcode %04"
              ]
          }
  

  Command for manual answer and hangup SIP call (for Homekit Automation etc.)

            {
              "accessory": "HTTP-SWITCH",
              "name": "Answer",
              "switchType": "stateless",
              "timeout": 3000,
              "onUrl": "http://127.0.0.1:8000/?/accept"
          },
          {
              "accessory": "HTTP-SWITCH",
              "name": "Hangup",
              "switchType": "stateless",
              "timeout": 3000,
              "multipleUrlExecutionStrategy": "series",
              "onUrl": [
                  "http://127.0.0.1:8000/?/sndcode %23",
                  "http://127.0.0.1:8000/?/sndcode %04",
                  "delay(1000)",
                  "http://127.0.0.1:8000/?/hangup"
              ]
          }          
  

  In this configuration, the open lock is performed by sending the DTMF code "0". Replace "sndcode 0" with the required value

  In this configuration, the SIP call hangup is performed by sending the DTMF code "#". Replace "sndcode %23" with the required value

• Download the necessary files

  cd /opt
  sudo git clone https://github.com/spbroot/sipdoorbell.git
  sudo mv /usr/share/baresip/ring.wav /usr/share/baresip/ring.wav.backup
  sudo ln -s /opt/sipdoorbell/doorbell.wav /usr/share/baresip/ring.wav
  

• Create a script for check the incoming call to baresip and notify ffmpeg about it

  sudo mkdir /opt/sipdoorbell
  sudo nano /opt/sipdoorbell/monitor.sh
  

  #!/bin/bash
  
  homebridge_log_path='/var/lib/homebridge/homebridge.log'
  doorbell_device_name='Doorbell'
  doorbell_ring_repeat=20
  date_format='%d/%m/%Y'
  
  count=0
  while true;
  do
    if wget -qO- http://127.0.0.1:8000/?/callstat | grep -q "INCOMING"; then
      if [[ "$count" -eq "0" ]]; then
        wget -q http://127.0.0.1:8080/doorbell?$doorbell_device_name > /dev/null 2>&1
        ((count++))
      fi
      tail -100 $homebridge_log_path | awk -v device_name=$doorbell_device_name -v date=`date -d'now' +$date_format` -v time=`date -d'now-1 seconds' +%H:%M:%S` '$0~date && $0~time && $0~device_name && /Two-way/ && /time=/ && !/time=00:00:00.00/ {system("wget -q http://127.0.0.1:8000/?/accept > /dev/null 2>&1"); exit 1}'
      if [ $? -eq 1 ]; then
        sleep 1
        while wget -qO- http://127.0.0.1:8000/?/callstat | grep -q "ESTABLISHED";
        do
          tail -100 $homebridge_log_path | awk -v device_name=$doorbell_device_name -v date=`date -d'now' +$date_format` -v time1=`date -d'now-1 seconds' +%H:%M:%S` -v time2=`date -d'now-1 seconds' +%H:%M:%S` -v time3=`date -d'now-1 seconds' +%H:%M:%S` -v time4=`date -d'now-4 seconds' +%H:%M:%S` -v time5=`date -d'now-5 seconds' +%H:%M:%S` '($0~date && ($0~time1 || $0~time2 || $0~time3 || $0~time4 || $0~time5) && $0~device_name && /Two-way/ && /time=/ && !/time=00:00:00.00/) {found=1} END {if(!found) system("wget -q http://127.0.0.1:8000/?/hangup > /dev/null 2>&1")}'
          sleep 1
        done
      elif (( "$count" > $doorbell_ring_repeat )); then
        count=0
      else
        ((count++))
      fi
    else
      count=0
    fi
    sleep 1
  done
  

  The device name "Doorbell" in the Camera FFmpeg Plugin must match with variable "doorbell_device_name"

  "homebridge_log_path" path to homebridge log file

  "date_format" date format of homebridge log file

  This script should answer the call when you enable TALK button, and end the call 5 seconds after disable TALK button or closing the application

• Making the script /opt/sipdoorbell/monitor.sh executable

  sudo chmod +x /opt/sipdoorbell/monitor.sh
  

• Create baresip service

  sudo nano /etc/systemd/system/baresip.service
  

  [Unit]
  Description=baresip
  After=network.target
  
  [Service]
  User=pi
  Group=pi
  Type=simple
  KillMode=process
  ExecStart=baresip -v -d -f '/home/pi/.baresip'
  Restart=on-failure
  RestartSec=3
  
  [Install]
  WantedBy=multi-user.target
  

  Change user, group and path if it nessesary

• Launch the baresip service and add to startup

  sudo systemctl daemon-reload
  sudo systemctl start baresip.service
  sudo systemctl enable baresip.service
  

• Create Sipdoorbell service

  sudo nano /etc/systemd/system/sipdoorbell.service
  

  [Unit]
  Description=Sipdoorbell
  After=network.target
  
  [Service]
  User=pi
  Group=pi
  Type=simple
  ExecStart=/opt/sipdoorbell/monitor.sh
  KillMode=process
  Restart=on-failure
  RestartSec=3
  
  [Install]
  WantedBy=multi-user.target
  

  Change user, group and path if it nessesary

• Launch the sipdoorbell service and add to startup

  sudo systemctl daemon-reload
  sudo systemctl start sipdoorbell.service
  sudo systemctl enable sipdoorbell.service