Programming 16x2 liquidcrystal screen with I2C bagpack

Other Hardware Displays
1

I am trying to get my ESP-32D to show my data on the screen for a 16x2 I2C bagpack but it is just shwoing blocks. any advice ?

pert 2

I moved your topic to a more appropriate forum category @miguelito134462.

The Nano Family > Nano ESP32 category you chose is only used for discussions directly related to the Arduino Nano ESP32 board.

In the future, when creating a topic please take the time to pick the forum category that best suits the subject of your question. There is an "About the _____ category" topic at the top of each category that explains its purpose.

Thanks in advance for your cooperation.

3

adjust the contrast

4

Assuming you have good parts, you can run the backpack at 5 V but pull up the I2C pins with about 3K resistors to 3.3 V, not 5 V.

The reason is that most of the displays I have used will not run well at 3.3 V, or if they do, they are marginal. Also, as @time_document_3108 suggests, adjust the contrast.

This works because the I2C pins are open collector (open drain). They do not drive the lines high. The pull-up resistors provide the high level.

5

Please show us the code you're using (including what LiquidCrystal_I2C library and version you're using) and a diagram (and/or a photo) of the connections.

Your problem could range from bad connections, to a bad I2C address, a wrong library, missing or badly connected pull-up resistors, or just a bad contrast setting. Hard to say without more information.

6

This would likely go much better if you showed your code? Things like what I2C address you are using?

Ron

7

Has power, but not initialized with the I2C library.

#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
    lcd.init(); // I2C LCD initialization
}
void loop(){}