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Questions &/or issues related to products in the LCDs and OLEDs category should be posted in this forum.
Another oddity, tried out the scroll example and it's showing "hello world" on multiple lines as it's scrolling left and right but it looks like the code should only have it printed once at the screen origin. maybe the controller got zapped and isn't operating properly?
SerLCD Library - scrollDisplayLeft() and scrollDisplayRight()
Gaston Williams - August 29, 2018

This sketch prints "Hello World!" to the LCD and uses the
scrollDisplayLeft() and scrollDisplayRight() methods to scroll
the text.

The circuit:
SparkFun RGB OpenLCD Serial display connected through
a Sparkfun Qwiic adpater to an Ardruino with a
Qwiic shield or a Sparkfun Blackboard with Qwiic built in.

The Qwiic adapter should be attached to the display as follows:
Display / Qwiic Cable Color
GND / Black
RAW / Red
SDA / Blue
SCL / Yellow

Note: If you connect directly to a 5V Arduino instead, you *MUST* use
a level-shifter to convert the i2c voltage levels down to 3.3V for the display.

License: This example code is in the public domain.

#include <Wire.h>

#include <SerLCD.h> //Click here to get the library: http://librarymanager/All#SparkFun_SerLCD
SerLCD lcd; // Initialize the library with default I2C address 0x72

void setup() {

//Wire.setClock(400000); //Optional - set I2C SCL to High Speed Mode of 400kHz

// Print a message to the LCD.
lcd.print("hello, world!");

void loop() {
// scroll 13 positions (string length) to the left
// to move it offscreen left:
for (int positionCounter = 0; positionCounter < 13; positionCounter++) {
// scroll one position left:
// wait a bit:

// scroll 29 positions (string length + display length) to the right
// to move it offscreen right:
for (int positionCounter = 0; positionCounter < 29; positionCounter++) {
// scroll one position right:
// wait a bit:

// scroll 16 positions (display length + string length) to the left
// to move it back to center:
for (int positionCounter = 0; positionCounter < 16; positionCounter++) {
// scroll one position left:
// wait a bit:

// delay at the end of the full loop:
I'm having a similar problems for both the setFastBacklight() function and displaying the firmware. I'm using the SparkFun 20x4 SerLCD - Black on RGB 3.3V (LCD-14074) from

For the setFastBacklight() function, I see a bunch of black squares printed onto the screen, but the backlight does not change in color.

For the firmware example, nothing appears on the display.