I have a central system in my appartment for opening/closing the door downstairs.
I want to get a notification whenever someone rings.
Opened up the device TEKNA-S GTWIN
Found a spot on the device that gives a voltage of 0.37V when the bell is pressed. (I assume this a sound signal since it is normally used to connect an extra speaker).
Connected this to GPIO4 D2, however nothing happens when the doorbell is pressed.
Could it be that the voltage is too low?
Yes. ESP8266 has 25% of supply voltage as max low level and 75% min high level. Normal supply is 3.3 so low level is max 0.8 V and min high is 2.5 V
You can instead use the analog input and read the voltage. The ESP analog input goes from 0 to 1 V. Some dev boards has resistor divider so it can work from 0 to 3.3 V. But you should be able to read 0.37 V vs 0 V on the analog input
I was actually thinking of doing that, however ESPHome tells me not to do this.
I get this error:
GPIO17 (TOUT) is an analog-only pin on the ESP8266.
binary_sensor:
@Addict Could you provide some details about where on the device you are picking up the 0.37V? I have the same intercom and want to do exactly what you were trying to achieve.