MorganS:
I don't understand the relationship of this schematic to the Ublox you described in the first post.
ublox connector J1
Pin1 is TX pin
Pin2 is RX pin
Pin3 is (+) pin
Pin6 is (-) pin
MorganS:
If you use a ground symbol then that's assumed to be system ground. All grounds connect to that. In particular, all of the pins labelled GND on the ATMEGA328 must all be connected to the SAME ground. You should not attempt to operate the chip with one ground floating.
This is a schematic using fritzing. In breadboard view this ATmega328 is a real Arduino board, no floating GND pins
Check npn-real.jpg and focus on yellow wire. Why this can cause a problem
