Arduino UNO LCD code to display data in loop

Question

I am new to Arduino. I want to display data read from the sensor on the LCD, first row fixed and 2nd row changing with sensor value. But I see first row for a while and then all garbage.

Here is the full code for reference:

#include <LiquidCrystal.h>
char ch;
int Contrast=155;
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

const int analogInPin1 = A0;  // Analog input pin that the potentiometer is attached to
const int analogInPin2 = A1;  // Analog input pin that the potentiometer is attached to
const int analogInPin3 = A2;  // Analog input pin that the potentiometer is attached to

int sensorValue1 = 0;        // value read from the pot
int outputValue1 = 0;        // value output to the PWM (analog out)

int sensorValue2 = 0;        // value read from the pot
int outputValue2 = 0;        // value output to the PWM (analog out)

int sensorValue3 = 0;        // value read from the pot
int outputValue3 = 0;        // value output to the PWM (analog out)

void setup() 
{
    Serial.begin(9600);

    analogWrite(6,Contrast); // setting contrast using code
    analogWrite(9,28836); // setting backlight led on

    // set up the LCD's number of columns and rows: 
    lcd.begin(16, 2);

    // Print a message to the LCD.
    lcd.setCursor(0,0);
    lcd.print(" CAR1 CAR2 CAR3 ");

    delay(200);
}

void loop() 
{
    // read the analog in value:
    sensorValue1 = analogRead(analogInPin1);
    // map it to the range of the analog out:
    outputValue1 = map(sensorValue1, 0, 1023, 0, 255);
    delay(250);
    sensorValue2 = analogRead(analogInPin2);
    // map it to the range of the analog out:
    outputValue2 = map(sensorValue2, 0, 1023, 0, 255);
    delay(250);  
    sensorValue3 = analogRead(analogInPin3);
    // map it to the range of the analog out:
    outputValue3 = map(sensorValue3, 0, 1023, 0, 255);
    delay(250);
    lcd.setCursor(0,1);

    lcd.print(outputValue1);
    lcd.print("  ");
    lcd.print(outputValue2);
    lcd.print("  ");
    lcd.print(outputValue3);
}

I guess you should also update the first line with the fixed text, within the second loop — OrElse
Please show declaration of 'lcd.print()'. It's not clear what it takes as a parameter and C does not have overloads. — Martin James
I cleared the whole lcd in loop and printed both lines. its working but now it goes blank in few seconds. What could be the problem. I have to reset arduino to see lcd data. and it again goes blank. — Kushal Shukla

Bing Bang Bing Bang · Accepted Answer · 2016-02-16T18:35:26

My guess would be lcd.print only prints strings. If there is a lcd.printf, that's the way. If not then you'll have to change the integer values to a string by using itoa() or sprintf().

Arduino UNO LCD code to display data in loop

2 Answers