@sundberg84 Which microscope are you using, looking 8:07 into your video?

Maybe off-topic, but those that don't know about Finite State Machines could have a look at these links for a start...
https://en.wikipedia.org/wiki/Event-driven_finite-state_machine
https://gamedevelopment.tutsplus.com/tutorials/finite-state-machines-theory-and-implementation--gamedev-11867

@ybirch Hi did you see the post I posted?
https://forum.mysensors.org/topic/9313/water-pressure-sensors/30
cost efficient, use a salvaged refrigerator compressor and purchase a long aqaurium airpump hose and a pressure transducer - might be fairly cheap

@neverdie I can only agree - to buy ans use a 3D printer is really good and some fun too

@mfalkvidd Thanks for the link to the post, I think I should upgrade and use aluminium foil as you done to make a GND shield around the PIR sensor

@executivul
Good point, But I have looked at the power/current budget.
I have 4 pcs relay, JQC-3FF 5V DC, spec: https://www.futurlec.com/Relays/JQC-3FF-05.shtml uses 0,36W each x 4 pcs = total 1,44W.
Usage of Wemos D1 Mini Pro is unknown, at least there is no spec...https://wiki.wemos.cc/products:d1:d1_mini_pro#documentation let says it uses 1 W
HLK01 is rated to provide 3W
Should be all ok

@gohan thanks I didn't think of the RF transmission from Wemos should impact PIR sensor, I only have thought of the power ripple. how far distance should affect PIR? I think mine is approx 2 cm apart

@gohan
No, I have a fairly large electrolyte cap on power supply on the controller PCB, to stabilize the PIR/Wemod/si7021 power source.

Actually when the bathroom door is open, and someone walk by the bathroom, the PIR will detect this and switch ON the light. I could consider to update 3D print to add a "wall" to block PIR.
The idea is that this PIR potentially can be used to connect to burglaralarm (but again I need to verify that I dont get false PIR reading due to sunlight)

@dbemowsk Thank you
For now as it's in early stage, I use the left switch to switch on (when I goto shower)on manually the fan, mirror heat, fan, and light and nightlight for 10min.
the right switch is only to start the fan for 5 min
I have not yet added humidity to start extraction fan automatically, but yes I will add this to the ESPEASY, rules

Bathroom controller. It consist of a relaybox with a HLK 5v power source, it's hidden in the closet. Then I have realy to light, nightlight, mirrorheat, and extraction fan
And then the controller it self it's a Wemos D1 Mini Pro, Si7021 Temp/Hum, sensor and a PIR HC-SR501

3D file is created with Freecad, STL files are available here:
https://www.thingiverse.com/thing:2890456