Hi everyone, I have a LCD HD44780 where the backlight is blinking. I havent used any code yet, just applied +5V to pins 2 and 15. GND is connected to pins 1 and 16. Could a lack of a series resistor for the LED backlight cause this? Or is it likely just a bad unit? Unfortunately I only have 1 LCD, so I can't swap it out to see if it just the unit.
Could a lack of a series resistor for the LED backlight cause this?
Yes. The current could be exceeding the 500mA capacity of the USB supply causing it's overload protection to come into play.
You are, however, following a good procedure. Get the backlight and contrast (don't forget pin 3) working before you connect the signal wires or try to run any code.