Hello, I am planning to interface my home intercom with home assistant through a Sonoff SV, but I really need your help because I have never opened an intercom since yesterday.
My intercom is a Siedle HT 511-01, I found a PDF containing the schematic (page 10) here:
I have a Sonoff SV with the Tasmota firmware and Home Assistant running on my RaspberryPi 3
I attach also a picture of my intercom opened and of my buzzer, as soon as I know the model I will write it here, but on it it’s written 8V - 6V
My goal would be that when someone rings the bell i receive a notification and then I can open the door through HomeAssistant
Do you think it’s doable? Can I connect the buzzer to the GPIO14 of my Sonoff SV and then open the door throught the relais of the Sonoff SV?
Hello again, I measured with a Voltmeter what happens to my doorbell when it rings and it gets 11V AC. I was thinking of using a rectifier and then a then a voltage divider in order to get my 3.3V in the GPIO pin. Does it make sense?
Moreover you say that I need a relay in between the buzzer and the Sonoff (SV), does it mean that I could use a Sonoff Basic as a Relay? Or do you mean a normal relay?
Thanks in advance for your answer!
A voltmeter wont show up voltage spikes that could very well be present from this sort of mechanical doorbell.
If you use the rectifier/divider method, add some sort of voltage clamping to the GPIO as well, a 3.3V Zener diode, or better yet, a 3.3V transil diode (faster acting, flatter cut off voltage).
Or just use a 12V AC relay. Relay coil connected in parallel with the bell, voltage free contacts connected to short the GPIO to ground, with a 10k pullup resistor connecting 3.3V to the GPIO.