Why connect a connector to Vcc

Using Arduino General Electronics
#1

Hi,

Could somebody tell me why on connector JP1 in this schematic pin 1 is connected to VCC?

schematic

Is it required? Good practice? Or some other reason?

Thanks

#2

Maybe like the Vin pin on an Uno, it's a means of providing a source of the input voltage as provided at the jack, back to the outside world?

#3

You might want to use it to power a sensor, as the rest of the pins on that connector go to the analogue pins (or GND).

#4

Thanks

#5

You absolutely want it to provide the analog reference voltage, so your sensor can be ratiometric.

#6