====== Internet connectino Watchdog ======
this is about creating a raspberry pi based appliance that monitors your internet conenction and if it goes down, automatically debugs it and restarts stuff like modem / router etc. as necessary. the device should also be reachable via an on-demand gsm link that can be initated by sms to login to the device and debug the link manually 

so far, this is just a collection of snippets of information and links, i'll write it up into a nice article one day, but not today ;) 

===== software installation =====
  apt update && apt install wvdial gammu gammu-smsd picocom 

===== SMS =====
  * Software: [[https://wammu.eu/docs/manual/|Gammu]]
  * Hardware: TP-Link MA260
  * on the tp-link stick the last serial device seems to be the one that can be used for sms (''gammu identify'' only gets information from that device). <code>gammu-detect | grep -B1 TP-LINK | grep ttyUSB | tail -n 1</code> to get the device name for the config
  * ''/etc/gammu-smsdrc.template''<code># Configuration file for Gammu SMS Daemon

# Gammu library configuration, see gammurc(5)
[gammu]
port = %PORT%
connection = at
#logformat = textall

# SMSD configuration, see gammu-smsdrc(5)
[smsd]
service = null
logfile = syslog
# Increase for debugging information
debuglevel = 0
RunOnReceive = /opt/process-sms.sh
</code>
  * ''/root/.gammurc''<code>[gammu]
device = %PORT%
connection = at
</code>
  * ''/opt/updateModemPort.sh'' <code bash updateModemPort.sh>
#!/bin/bash
port=$(gammu-detect | grep -B1 TP-LINK | grep ttyUSB | tail -n 1 | awk -F = '{print $2}' | tr -d " ")
sed -e "s|%PORT%|${port}|" /etc/gammu-smsdrc.template > /etc/gammu-smsdrc
sed -e "s|%PORT%|${port}|" /root/.gammurc.template > /root/.gammurc
</code>
  * installation: <code>apt install gammu gammu-smsd</code>
  * <code bash process-sms.sh>#!/bin/bash
for i in `seq $SMS_MESSAGES` ; do
    numvar="SMS_${i}_NUMBER"
    textvar="SMS_${i}_TEXT";
    echo "${!numvar}:${!textvar}" >> /tmp/messages
    if [ "${!textvar}" == "connect" ]; then
      echo "connect!" >> /tmp/messages
    fi
done
</code>
===== GSM Link =====
  * Hardware: See above
  * Software: wvdial 
  * config: ''/etc/wvdial.conf.template'' <code>[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Init3 = AT+CGDCONT=1,"IP","internet"
Modem Type = Analog Modem
Baud = 960000
New PPPD = yes
Modem = %PORT%      
ISDN = 0
Phone = *99#
Password = { }
Username = { }
</code>
===== Relay Card =====
  * Hardware: Conrad electronics, part number 967720 (Relaiskarte 8Fach Seriell)
  * Software: [[http://www.thomas-dohl.de/?Projekte___Relaiskarte]]

===== serial console to router =====
  * via dual prolific basead usb to serial converter, one link goes to the relay card, the other to the serial terminal of the pfsense router. 
  * usb link is extended down to the basement via cat7 link, I simply cut a usb extension cord into two and attached RJ45 plugs to both ends with identical pin layout. works like a charm :) 
  * software: ''picocom''