Hacking an RF remote using a RCWL-0516 motion sensor and an optocoupler.

[foor_bridge_rectifier]

Hi everyone !. I was trying to hack buttons of this rf remote for led strips
I opened the remote and found out the traces for the power button and soldered two wires to the pads on the remote's pcb.

I want to trigger the power button using ths motion sensor module and an optoisolator . So i connected the pins of the remote button to the collector and emitter (minding the polarity ofc). And input to the opt-out of sensor using 120ohm resistor.

The problem is that the thing works perfectly for the first time after motion detection and then the the optoisolator stays high.

I tried using an Arduino (both mega and a nano), individualy the Arduino can control the remote using optoisolator just fine but when I try to get an input from the rcwl sensor to trigger the opto , the same problem appears again (the output to isolator get stuck on high after the initial motion detection event). I checked with the serial monitor for the sensor and is is working just fine.

I really want to know what is going wrong. Any help would be hugely appreciated.

Reference -
Block diagram attached.

Add/edit-  the optocoupler(pc 817) is a simple transistor type and not a triac type. But it is behaving like a triac (by staying high even when input led shuts off)

[wvmarle]

Can that sensor handle a 9V supply?

Can that sensor produce that much current (17 mA) on its output? (2-5 mA is more than enough for most optocouplers).

OP's image:

[foor_bridge_rectifier]

The sensor supports 3.3 -24V.
Yes (mac current out = 100mA)

[foor_bridge_rectifier]

Individually both the components (opto isolator (triggering remote using blink sketch) and the sensor(monitoring output using serial monitor) work just fine . But when i try to use both at the same time (using the button sketch for example) , same problem occurs again (opto stays high (along with onboard led) indefinitely)

[foor_bridge_rectifier]

Sharing some photos of the rf remote -