LIne 4 of the 20 x 4 LCD Display

Components & Accessories Displays
1

Hi,

I’m using the 20x4 LCD connected to a SparkFun Thing (esp32) via i2c Qwiic. The display works fine if I only use the first 3 lines. If I try to use the last line - the screen goes blank.

e.g. this works

Wire.beginTransmission(DISPLAY_ADDRESS1); // transmit to LCD Screen

Wire.write(‘|’); //Put LCD into setting mode

Wire.write(‘-’); //Send clear display command

Wire.println(messageA);

Wire.println(messageB);

Wire.println(messageC);

Wire.endTransmission(); //Stop I2C transmission

this does not - blank screen

Wire.beginTransmission(DISPLAY_ADDRESS1); // transmit to LCD Screen

Wire.write(‘|’); //Put LCD into setting mode

Wire.write(‘-’); //Send clear display command

Wire.println(messageA);

Wire.println(messageB);

Wire.println(messageC);

Wire.println(messageD);

Wire.endTransmission(); //Stop I2C transmission

I have tried sending the

Wire.write(‘|’); //Put LCD into setting mode

Wire.write(0x05); //Put LCD into 4 line mode

The screen shows Lines 4 Width 20 on boot up - but still won’t display anything when I attempt to include the 4th line.

any clues would be greatly appreciated.

2

Maybe try:

Tossing a delay after changing the settings; also maybe try inputting both width and height if entering size manually

Be sure you are using SerLCD board feinitions and OpenLCD libraries https://learn.sparkfun.com/tutorials/av … -guide/all

See if using the DEC codes work instead?

Finally, it might help to try editing the setting.h file directly https://github.com/sparkfun/OpenLCD/blo … settings.h in your folder/sketch