I'm quite confused after a few search, so I'm trying to explain my little problem here.
Context : A circuit in two parts and a cable in between :
- a micro-controller, for instance a wemos d1(other devices attached to MCU, that's why the 2 parts are separated)
- a remote PIR sensor, powered by 3v
- a TIP120 to remotely control a led strip with 12v pwm
Screenshot below for a better understanding :
Currently the cable needed is 5 cores. I wonder if I could use a 4 cores instead.
(I've bought 4 cores thinking I would be sufficient :()
By replacing the TIP120 by a P-Channel MOSFET, high side switching, can I share a common ground in the cable ?
I've seen such high side switching designs, but I'm really not sure about the common ground between 12v led circuit and MCU power)
Screenshot below is a just to understand my idea, it is not correct :
Thanks a lot for reading