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

RoatanBill
Posts: 3
Joined: Tue Jan 30, 2024 2:55 pm

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

Postby RoatanBill » Fri Mar 08, 2024 6:35 pm

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?

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jgustavoam
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Location: Belo Horizonte , Brazil
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Re: Why does changing pin assignments cause 1602A to display trash?

Postby jgustavoam » Fri Apr 05, 2024 12:34 am

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/
Retired IBM Brasil
Electronic hobbyist since 1976.

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