You could also do the same thing with an ESP8266 and a relay. What is the voltage coming out of the buzzer? If it’s between 5 and 12, you could even run the board off the buzzer as well, as these are very low power boards. It all depends on how much modification you’re willing to do with the intercom that you’ll either have to pay for or put back when you move out. Take a look at the ST_Anything project.
1 Like