I am creating a circuit with several sim00l connected to different UARTs each with its own external power. But I'm curious if having other objects like cooler-fan connected to other GND of the rpi would not affect the functionality of my sim800l regarding what is known as ' floating ground or FG'. Here is what I plan to implement https://ibb.co/KXxCXFf. In the same way I would like to know if my common ground connection between sim800l and rip4 would work De Thank you.
Connect several sim800l with external power supply to the uart of ip4 and floating ground
you must have a common ground, unless you use opto-isolators ... your configuration looks ok ... how is the RPi powered?– jsotolaApr 29, 2022 at 15:10
Thanks, I am powering the rpi with an external power supply (5V and 3.0 A).– oscar gutierrez VargasApr 29, 2022 at 15:48
Well friends if the circuit worked, is more I edited it by changing the lipo battery power supply for power regulated with lm2596 and a 4700uf capacitor for each sim800l module. Thanks