Hardware Reference
In-Depth Information
alternatively, you can use solderless headers, which need to be pushed all the way into
the holes to make a good connection. Although it may seem easier to use solderless
headers, they can be quite diicult to push into place and you might need a lot of
patience to do it. I ind that wiggling the headers in small groups of ive or six at a time,
while applying pressure, is the best way to add them to the LCD screen.
Mounting the LCD Screen and Wiring
Up the Breadboard
Follow these steps to set up the LCD screen. Refer to Figure 9-2 for additional guid-
ance as you work.
1.
Lay your full breadboard out lengthways in front of you so that the longest side
runs parallel to the edge of the table directly in front of you. Push your prepared
LCD screen's header pins into the holes, starting from C5 and going all the way
to C21.
2.
Next, add the potentiometer into pins F1 to F3 above the left end of the LCD
screen. You will be using the potentiometer to adjust the contrast of the LCD
screen.
3.
Place your unplugged Raspberry Pi next to the breadboard (see Figure 9-2) and
add the Raspberry Leaf (
www.doctormonk.com/2013/02/raspberry-pi-
and-breadboard-raspberry.html
)
for your Raspberry Pi board revision
over the top of the GPIO pins (you'll remember the Raspberry Leaf from
Adventure 8). You will be connecting quite a lot of jumper cables from the LCD
screen to your Raspberry Pi, and you'll ind it easier with the Raspberry Leaf in
place as a guide.
4.
In order to send data to the LCD screen, it needs to be wired as follows. Start
with pin 1 (the far left) of the LCD screen and attach the cable to the correct
destination (use the diagram in Figure 9-2 to help you):
•
Pin 1 of the LCD goes to the ground or negative blue strip of the breadboard
(black male-to-male cable on diagram).
•
Pin 2 of the LCD goes to the 3.3v or positive red strip of the breadboard
(red male-to-male cable on diagram).
•
Pin 3 (Vo) connects to the middle of the potentiometer (orange male-to-
male on diagram). Note that the potentiometer has three pins; the orange
wire should be placed in a breadboard slot above the potentiometer in the
middle.
•
Pin 4 (RS) connects to the Raspberry Pi GPIO 25 (yellow male-to-female
cable).
•
Pin 5 (RW) goes to the ground or negative of the breadboard (black male-to-
male cable).
