LCD display text is very dim

Projects General Guidance
1

So, my LCD display text is very dim, and only visible from certain angles and almost not visible at all on camera. Moving around the potenciometer does very little, and can only make the text dimmer. Please help me resolve this...

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2

  • Difficult to decipher the wiring.

  • Show us a wiring schematic.

  • The contrast pot should work as is, however, you could try connecting pot between 5v and GND.

3

It looks to me like the potentiometer was connected to GND twice instead of GND and 5V:

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Am I wrong?

PS: it is better to use LCD with I2C interface which in addition to simplifying the connections already has the trimmer for the contrast.

4

Here is a picture. I used the same wiring schematic as shown in the starter kit book for priject 11 (crystal ball). I did it without implementing the tilt sensor at the top, so only the lcd screen. I tried both varients with and without connecting the pot between 5v and GND and both to GND.

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5

I can only use the regular LCD as for now sadly... Also both going to GND can wor, as well as GND and 5V. I actually get more control over th pot with both going to GND.

6

Those devices have a variable voltage pin that adjusts things. Look on the back of the module for something you can stick a screwdriver in. Normally X head "pot" (blue/white). Likely just set at random when the device was manufactured

Play around with the (screwdriver) "setting" until things are as you want them.

7

I doubt it, never seen/used in sich way. What voltage value you'll bring to the pin if the pot is connected to GND only, except 0V? You must connect it to 5V and GND to get a variable value to give the contrast input control.

8

Sorry but what devices? I cant seem to find what youre saying to play around with.

9

  • BTW, both 10k pot outer terminals going to GND does work.

  • Try 220R on the backlight.

10

Sounds like you are thinking of a LCD display with an I2C backpack, which has the contrast adjustment pot on board. In this case, @koltam09 does not have the I2C board and is using a pot on a breadboard.

I have seen posts (such as this ) advocating not using the connection to 5V on the pot, and apparently it will function properly.

To the OP, have you checked the value of the resistor going to the backlight? Can't tell from the photo how bright that is.

11

Im using a 220R on the backlight am I not? I checked the table and it says its the 220R.

12

Its a 220ohm resistor. Th LCD backlight is petty bright but the text is very dim.

13

Red Red Black = 22 ohm

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14

I dont have the 4 band type, I have the 5 band type only.

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15
  • 220R 5 band.

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  • In the Arduino IDE, use Ctrl T or CMD T to format your code then copy the complete sketch.
    Use the < CODE / > icon from the ‘posting menu’ to attach the copied sketch.
16

Yes thats the one Im using. Here is the code:

#include <LiquidCrystal.h>

// Pins: RS, E, D4, D5, D6, D7
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  lcd.begin(16, 2);
  lcd.print("Hello world!");
}

void loop() {
}
17
  • Are you using a 10k potentiometer ?
18

Yes I am.

19

  • Change out your Arduino +5v (red) and GND (black) wires for new wires.

  • Measure the voltage between the display’s Vss and Vdd terminals.

20
  1. Can I use any other wires, like the orange ones for example Ive used?
  2. How do I measure that? I dont think I gt the tool for that in my starter kit.