MobiFlight Community Support

Hi Guys, I was wondering if it is ok to power multiple arduinos from one power unit. My main concern is the ground. Is ok for all the GND's to be linked as I also would be powering stepper motors and 7 seg LED's. I'm not worried about the amount of devices being powered just if it's ok to have GND's from different arduinos

Coco

Hi Coco,

I think it can not be mentioned often enough. GND is the common unified (basic) potential to which all other potentials refer.

Assuming you want to connect to a MEGA, which has its GND, a second MEGA or record in the system, then it is essential to connect the GND of the 2nd MEGA with the GND of the 1st MEGA, so that both MEGA one have common potential.

It is the same with other components connected to the system. Always connect to GND.

It may also be that GND is already connected via the USB bus, as it is with a HUB. An (additional) direct connection to the GND does not hurt and you are always on the safe side.

If components are to be connected to an external power supply, the GND must also be connected here. This is especially true when data is being transferred. The transmitter outputs the data with a certain voltage (amplitude). How should the receiver know how big this data is (amplitude) if it has no reference potential?

As I said, who has a multimeter, can measure whether GND is already supplied via the USB potential. However, if other components are added that are not connected to the USB bus, the GND MUST be connected.

As a thought, anyone can remember that it takes the GND, if you want to have a closed circuit, because only then all components work with the same reference potential.

You can also remember: In case of doubt, always install an additional GND cable.

Many Thanks Stephan