I'm currently trying to create a system to open my apartment's door (using the buzzer) using my raspberry pi, and thought that using an optocoupler would be the best solution - although I'm a complete novice.
The only optocoupler that I've been able to find locally is this one, however I'm pretty lost on whether or not this would be suitable for my project, and if so I'm not sure what kind of resistor I would need to buy to be able to use it.
The Raspberry Pi has a 3.3V source voltage, and I was using this site to try to calculate what ohm resistor I'd need, but I sadly don't see the forward voltage on the specifications of this product.
tl;dr: Is this optocoupler suitable? If so, how many ohms would the resistor I buy need to be?
Thanks for your help, and sorry for the probably trivial question.