Here are the sketches for the following youtube video.
The Different sketches can be used like this:
SendCallToSpecificSerialNr: You can simply enter the serial nr. you want to call via "normal" numbers and it will calculate the cmd for you.
TCSparserUNOMitCOMP: use internal comparator of Arduino UNO on pin D6 and D7, can be used with TCS software.
AnalogINparserESP8266: Parse incoming Bus messages via Analog in without interrupt on ESP8266/ not as reliable as the interrupt ones because the AnalogIn needs to be called as much as possible.
For all sketches see the Video for Schmeatic.
Happy Intercom Hacking!
See this Repo for another aproach from another guy who is using the TCS intercom: https://github.com/Syralist/tcs-monitor