Parallax LCD library for use with Arduino 1.0 and higher
C++ Arduino
Latest commit 1732f29 Jan 16, 2015 @iamthechad Behave correctly for 4x20 LCD
Fixes #5

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Parallax LCD

The Parallax LCD library allows for writing to Parallax three wire LCDs. It is known to work with Parallax LCD's (27976, 27977, 27979).

For more information about Parallax LCDs, see


The library offers the following functions:

  • setup
  • on
  • off
  • scrollLeft
  • scrollRight
  • empty
  • cursorUnderline
  • cursorBlock
  • cursorOff
  • cursorOnChrBlink
  • cr
  • lf
  • backLightOn
  • backLightOff
  • playTone
  • setCustomCharacter
  • printCustomCharacter
  • pos
  • at


Using the library is simple. See the included example for more.

#include <SoftwareSerial.h>
#include <ParallaxLCD.h>

ParallaxLCD lcd(2,2,16); // desired pin, rows, cols

void setup () {
  delay(1000); // Wait for the LCD to start up,3,"Hello World!");


  • Clone this repository or select the "Zip" button above to download the code.
  • Place the directory into libraries within your Arduino Sketches folder. (You may have to create the libraries folder.)
  • Restart the Arduino IDE if it's running.
  • Go to File->Examples. There should now be an entry for parallax_lcd in the list. Select it to see the example.
  • Using the example as a guide, write your own code!


This library is provided under the MIT license. You can obtain a copy of this license at


Original Work done by: Douglas Farrell

Based on SparkFunSerLCD.h from: allen joslin

Tone/Custom character support added by: Martin C. Stoufer