I have a current project i am working on and wanted some advice on power.
as of right now i have the following
Uno R3
EthernetShield
rs232 max
PFC8574 I2C board
12 key keypad
magstripe reader
LCD compatible VFD 20x2 display (some will debate the combatibility)
i am using the 5v from adrino to power the rs232max, PFC8574,magstripe reader, UNO, and VFD
the vfp and magstrip reader could be up to 12 inches away from the UNO
right now everything works could but i will be developing a pcb for the connectors and to make things simple to hook up.
the main question i have should i continue with just using that 5v or should i send the 9v from the UNO over to my interface pcbs and regualte it down to the 5v or will it not make a difference
i will try to do a rough drawing to show interconnections