Step 1: The ATMEGA328-MCU
Required parts:
Placing the parts:
1*ATMEGA328
1*crystal 16 MHz
2*C 22 pF
1*resonator 16 MHz
or
1*crystal und 2*C 22 pF
or
1*resonator
1*ATMEGA328
(make sure to align the notch!)
The 16 MHz resonator is
soldered into these
holes.
The 16 MHz Crystal is
soldered into these two
holes. Then you also
need 2*22 pF capacitors
(C11 and C12).
Right at the start you have a tough choice to make. Do you use a 16 MHz resonator or a 16 MHz crystal with
two 22 pF capacitors as the clock for the ATMEGA328-MCU? One tip: They‘re the same. A resonator consists of a
crystal with two capacitors. You should choose whichever one is easier to find.
Make sure to line up the small semicircular notch in the short side of the ATMEGA328 with the mark on the
board.
Experienced solderers can attach the MCU directly onto the board. Beginners should use the socket (Make sure
to line up the notch in the socket as well) and later add the MCU. This is because the MCU is more sensitive to
the heat from the soldering iron. This will not affect the overall height of the board because there are still taller
components that affect the overall clearance.
We don‘t need the small solder pad labeled „X1“ so we will ignore it. It is there because some crystals need a
ground plane.