Uno + LCD Keypad Shield - no char display

Other Hardware Displays
1

Hi all,

I'm sure I'm doing something newbie stupid here, but....

I have an arduino uno connected directly to an LCD keypad shield (D1robot), and have uploaded a few different sketches to test it. No matter which sketch I upload, the LCD backlight stays lit but with no characters on the display. Turning the potentiometer does nothing.

Thinking I might have a dud, I tried a different lcd keypad shield (robotdyn), and it does the same. I tried a different arduino uno, and it does the same with both LCD shields.

I have tried the original example sketches, with the original pin configuration, and with the updated pin configuration (8, 9, 4, 5, 6, 7), and neither works. I've also tried some sketches designed specifically for the LCD keypad shield, no joy.

I've also tried with just usb power, and with a separate 12v 2a power supply.

Can anyone help troubleshoot this with me?

Thanks,

Lee

2

One down. Turns out the potentiometer was about 10 turns too low. Oops

The other one still isn't working though. Troubleshooting that one next

3

#include <LiquidCrystal.h>

LiquidCrystal lcd(7, 8, 9, 10, 11 , 12);

void setup() {
lcd.begin(16, 2);
lcd.setCursor(0,1);
lcd.write("PhanNominal: ");
}

void loop() { }

This worked for me. Try it, it may work. Im a nubee too.

4

Thanks for the code, but it's not working for me. I'm starting to think the LCD shield is damaged.

I have a working arduino with a working LCD keypad shield. If I swap out the working LCD keypad shield for this one, all I get is blocks on the top row - no characters.

This keypad shield was previously working, but I needed to remove the pin headers to allow it to fit in the case for a project. I'm thinking I may have damaged something when desoldering the headers. I've checked all adjacent pins, and there are no shorts that I can find. So, either I rogered something, or there was a jumper between two pins that I inadvertently removed.

If anyone has a suggestion, I'd love to hear it. If not, it'll go in the recycle :frowning:

Lee