Sparkfun Electronics RedBoard, Manual, Page: 82 / 88

LCDs are everywhere! From advanced LCDs like your
television, to simple notification screens, this is a very
common and useful display!
Circuit 2
Arduino Code:
15
Troubleshooting:
The Screen is Blank or Completely Lit?
Fiddle with the contrast by twisting the potentiometer. If
it’s incorrectly adjusted, you won’t be able to read the
text.
Not Working At All?
Double check the code, specifically that you include the
LCD library.
Screen Is Flickering
Double check your connections to your breadboard and
Arduino.
Initially, you should see the
words “hello, world!” pop up
on your LCD. Remember you
can adjust the contrast using
the potentiometer if you can’t
make out the words clearly. If
you have any issues, make sure
your code is correct and
double-check your
connections.
This bit of code tells your Arduino IDE to include the library for a
simple LCD display. Without it, none of the commands will work,
so make sure you include it!
#include <LiquidCrystal.h>
Code to Note:
Real World Application:
Open Arduino IDE // File > Examples > SIK Guide > Circuit # 15
What you Should See:
This is the first time you’ll fire something up on your screen. You
may need to adjust the contrast to make it visible. Twist the
potentiometer until you can clearly see the text!
lcd.print(“hello, world!”);
IOREF
RES
ET
RESET
7-15V
SCL
SDA
AREF
GND
13
12
~11
~10
~9
8
7
~6
~5
4
~3
2
1
0
TX
RX
13
3.3V
5V
GND
GND
VIN
A0
A1
A2
A3
A4
A5
POWER
ANALOG IN
DIGIT
AL (PWM~)
ON
ISP
TX
RX
IOREF
RES
ET
RESET
7-15V
SCL
SDA
AREF
GND
13
12
~11
~10
~9
8
7
~6
~5
4
~3
2
1
0
TX
RX
13
3.3V
5V
GND
GND
VIN
A0
A1
A2
A3
A4
A5
POWER
ANALOG IN
DIGIT
AL (PWM~)
ON
ISP
TX
RX
LEARN. SHARE. HACK.
Page 80