Arduino screen with photoresistor

Question

Hi.

Im building a mailbox with a screen that changes the message wheter you have mail or not, but I need some help with my code.

This is what I have for the moment, but it doesnt seem to work like I would like it to.

#include <LiquidCrystal.h>

#include <LCDKeypad.h>

LCDKeypad lcd;

const int threshold = 100;

const int analogPin = A0;

void setup() {

int analogValue = analogRead(analogPin);

if (analogValue > threshold)

{

lcd.begin(16, 2);

lcd.print("text1");

}

else

{

lcd.begin(16, 2);

lcd.print("text2");

}

void loop() {

}

Any help is higly appriciated!

Be sure to tell me some suggestons, if I should use a photoresistor or not.

clem57 · Accepted Answer

The code in setup runs just 1 time. The code in loop can run many times, but a delay is wise to not overload the sensor with testing.

Clem

#include <LiquidCrystal.h>

#include <LCDKeypad.h>

LCDKeypad lcd;

const int threshold = 100;

const int analogPin = A0;

void setup() {

}

void loop() {

int analogValue = analogRead(analogPin);

if (analogValue > threshold)

{

lcd.begin(16, 2);

lcd.print("text1");

}

else

{

lcd.begin(16, 2);

lcd.print("text2");

}

Delay(1000); // delay 1 second

}

mcb1 · Answer

I don't have the LCDkeypad.h file so I can't verify this runs/compiles.

#include <LiquidCrystal.h>
#include <LCDKeypad.h>

LCDKeypad lcd;


const int threshold = 100;
const int analogPin = A0;
int analogValue;




void setup() {
  lcd.begin(16, 2);

  }


void loop() {
  analogValue = analogRead(analogPin);
  lcd.clear;

  if (analogValue > threshold)
  {
     
     lcd.print("text1");
  }
  else
  { 
     lcd.print("text2");
  }

delay(1000);
}

As Clem pointed out adding a delay stops it just running flat out.

There are some examples in Arduino and each library often adds some more.

You will find some in LiquidCrystal which you can adapt ...

Mark

Arduino screen with photoresistor

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