I made a prototype of multisensor circuit with temperature, humidity, PIR, etc using a ESP8266.
My idea is to put each of this module in each house room. To achieve this and I want to put the entire PCB in the back side of the plastic plate used to cover empty switches holes on wall switch plate (the 3 black plastic items in the photo below)
Each of switch hole cover is about 20x40mm and the available depth in the back of switch plate is about 40/45mm. To avoid batteries I want to power the circuit using the AC 230V main power.
Can you suggest me the best way to power the circuit with the main requirement to keep PCB as small as possible?
- using switching PSU?
- using capacitor impedance?