I am working on a design for a Arduino driven project that controls a 1.7A stepper motor and 2 small solenoid valves. I am using a 12v power supply (Meanwell MDR-60-12) to power the stepper motor (though a TB6600 driver) and the solenoids (controlled by 2 channel solid state relay). I have been using the USB port both to power the Arduino (which supplies 5v power to the relay module) and to monitor the system through the serial port.
I am attaching a diagram of the circuit layout to clarify how I have put all of this together.
As a move forward to finalize this design I have a few questions:
1) Do I need to create a direct common ground between the 12V power supply and an Arduino ground pin?
2) Should I power the Arduino with a dedicated power supply rather than relying on a computer USB port?
3) Should I be including capacitors or diodes at any points in the circuit for added protection?
4) Is there anything else I am missing here?
Thank you - I appreciate any and all constructive feedback!