Serlcd setFastBacklight command not working on v2.3 board

I was trying out the FastBacklight example but it isn’t changing my SerLCD V2.3 boards backlight. the normal setBacklight command works fine. any idea how I can get this command working? maybe a firmware update?

Also looks like the show firmware example with the lcd.command(‘,’) isn’t returning the firmware value. it’s actually not displaying anything. I tried a reset of the board by connecting the RX to ground but still nothing.

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.begin();

lcd.begin(Wire);

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

// Print a message to the LCD.

lcd.print(“hello, world!”);

delay(1000);

}

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:

lcd.scrollDisplayLeft();

// wait a bit:

delay(150);

}

// 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:

lcd.scrollDisplayRight();

// wait a bit:

delay(150);

}

// 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:

lcd.scrollDisplayLeft();

// wait a bit:

delay(150);

}

// delay at the end of the full loop:

delay(1000);

}

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 https://www.sparkfun.com/products/14074.

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.

I think that the issue may be that the firmware is too old for the current code. Has anyone tried upgrading the firmware to the newest version?

Sounds like your LCD shipped with the V1.0 firmware. Follow the firmware update directions in the troubleshooting section of our hookup guide and that should get you going.

https://learn.sparkfun.com/tutorials/av … leshooting