I'm just learning MOSFETS but I think they have a 4.5V or 10V trigger threshold. I'd use a 5V module and stick a logic level converter in front of it, or you can make a logic-level converter from an N-MOS:
I think that's right.
In this case the 5V_D_Pin would be the module and the 3.3V_D_Pin would be your 3.3V PWM pin.
EL817 V Typical Forward = 1.4V
Typical LED1 V Forward 1.4 V.
EL817 Forward current IF 60 ma.
3.3V -1.4v - 1.4V = 0.5V
0.5V /1K = 0.5 mA --- >> Not enough to light the LED on the
Short circuiting LED1
3.3V -1.4v = 1.9V
1.9V /1K = 19 mA --- >> It may be enough to light the LED of the EL 817.
We can exclude anything to do with the processor and its pins, I applied 11V to the trigger connections and the outputs still produced nothing. Same LED and resistor works fine when connected to the main power supply connectors and trigger connections.
When looking at another wiring schematic I also wondered about shorting out a resistor and LED to improve signal.
I am trying to find modules that work off the shelf so I can recommend them to people using my stuff hence my endeavor to find a working one that people can just buy with confidence.