I am trying to galvanically isolate a brushless ESC from my Arduinbo Uno with a optocoupler PC817. However this doesn't seem to work. When I give the ESC the PWM signal directly from the Arduino it responds accordingly. But when I go through the optocoupler it doesn't do anything.
The thing is that I tried to control a brushed ESC via the optocoupler and then it works fine. Both ESCs work with the same PWM signal (1000 - 2000us). I didn't change anything from my setup but to connect the brushless ESC in the same way as the brushed but I get nothing.
I have the suspicion that it might be due to the resister value. I have attached a sketch of my setup.
I would highly appreciate any help! Thanks.