I want to connect my wireless door bell to a raspberry pi to play music when the bell activates.
sounds easy but it isn´t. I already asked the manufacturer if there is a place on the PCB where i could connect to.
they told me: the version you plug into a outlet is always under current. the led only indicates power and the speaker also is not at 0V while off.
so i was thinking i could wire the speaker and the 3.3v output with a NAND-gate to an input pin.
as soon as the speaker plays music he should get 0V as part of his audio signal. i know a simple transistor would do the trick but with a NAND gate i can monitor something else with the same circuit. i know my diagram is missing some resistors and a ground connection, but those are not the problem. i think a NAND microchip wont be able to handle the speaker signal but i have no clue what kind of transistor to use to build my own NAND gate.
all help is appreciated. especially if you can tell me a faster way to find the right transistor model than checking datasheets until i find the right one by chance. if my plan is stupid, just tell me why please. i know i only know the basic concepts of electronics so you wont make me cry;)
Thank you for your time,