I live in Brazil, old house, mostly 110vac on all outlets and appliances.I don't want to mess with wiring around the house right now but I want to make my doorbell smarter.
The plan is to receive a notification on my phone when someone rings the bell. The doorbell is pretty simple. I get two wires one is interrupted by a switch when you close the switch the doorbell uses mechanical system to make the noise. It runs on 110vac no 5v dc or 3.3v dc. What would be the easiest way to make this usable with an arduino or esp32?
I have a 5v power supply to power the board.
I could use two esp32 and make it totatlly wireless but again I don't have power supply at the switch side and those cables have to go through solid concrete walls and I really dont wanna mess with that right now.
I believe there are several solutions.
I will mention 2 of them.
In parallel with the bell, you place a 110V/5V source, and connect this source to a pin on the ESP32. Keep reading this pin. When it is HIGH you send the message to your cell phone.
In parallel with the bell, you use an opto-coupler properly connected with resistors to reduce the opto-coupler LED lighting current to +0- 15 mA.
Connect the other side of the opto coupler to the ESP32. Keep reading this pin. When it is HIGH you send the message to your cell phone.
I moved your topic to an appropriate forum category @acleitao.
In the future, please take some time to pick the forum category that best suits the subject of your topic. There is an "About the _____ category" topic at the top of each category that explains its purpose.
You can use a current transformer, that you run the dorbell wire thru. Lets sat 0.1A/0,1A (you must match it with the current the bell draw). The current transformer has a resistor, as as burden. The voltage over the burden resistor is sent thru a 0.1uF capacitor, to the middle of a voltage divider. The voltage divider is set with +5V and gnd. Calculate the voltage divider so the AC voltage from the current transformer will swing on a 2.5VDC bias voltage. So, the voltage will never go under 0V, or over 5V, as this can damage the analog input of the MCU you are connecting to. So, when the bell rings, AC voltage is sent to your MCU and you read a analog value, that set of your logic inside your MCU, to send you a notification.
The notification: You could: 1. Send sms, with a gsm module like simcom 7000G, or 2. Send push warning thru the internet.
Note: There are several cheap alternatives out there, allready made, like the "Ring" system with camera.
Yes, quite easy. You DO NOT want to sense 110 VAC, but sense the CURRENT when the push button completes the circuit and rings the bell.
You do that by making a small transformer by wrapping many turns of insulated wire around ONE if the wires going to the bell. Use a single diode and capacitor to create a DC voltage when the bell rings. Watch for that pulsing DC voltage to appear with an Adruino digital pin.
Measure the DC voltage with you meter to verify all is working and the generated voltage is not too high for your Arduino pin. Fewer turns of wire if too high.
I would go along with that just thinking of the bell push having 110v on it outdoors in the rain seems very unlikely as does using the thin flex found on door bells . The OP needs to check this out .
