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Why does changing pin assignments cause 1602A to display trash?

Posted: Fri Mar 08, 2024 6:35 pm
by RoatanBill
Using the example at https://www.circuitschools.com/interfac ... thout-i2c/ I have the following line that works on a WROOM-32 module under the Arduino IDE:
LiquidCrystal lcd(19, 23, 18, 17, 16, 15);

If I change that to:
LiquidCrystal lcd(19, 23, 33, 25, 26, 27);
and also change the breadboard wiring to match, I get some legible text but lots of junk characters. I jiggled the breadboard wires thinking it is a connection issue but that has no effect.

I thought I could use any GPIO pins that didn't have any restrictions on boot, strapping, etc so why doesn't this work?

Re: Why does changing pin assignments cause 1602A to display trash?

Posted: Fri Apr 05, 2024 12:34 am
by jgustavoam
Check all connections between the LCD and the ESP32.
There may be an incorrect connection.
Measure the 5V supply on the LCD. Make sure it is suitable.

Reference to read:
https://randomnerdtutorials.com/esp32-p ... nce-gpios/