LCD displaying incorrect Count - Serial is correct

Projects Programming
1

I have a basic counting project i'm working on. It's been 5 years since I last worked with an Arduino...
When the sensor detects an object, it activates a relay to move the object and displays a count, then pauses & waits for next object. I'm still waiting for my parts to arrive to test fully, but using a simulator I have a discrepancy between the actual count (Serial) and the displayed count by 1.
eg: counted 1 / displays 0, counted 2 / displays 1... etc...

video demo: https://drive.google.com/file/d/18zAv300GGIrNI5NvT6xuWbkUnzbKej4D/view?usp=sharing

My Code:

#include <LiquidCrystal.h>
#include <EEPROM.h>

LiquidCrystal lcd(13,12,11,10,9,8);
const long Limit = 10;
int count=0;
int ttlcount=0;
int relay = 3;
int sensor = 5;
const long HoldTime = 1500;
const long Wait1 = 600;
const long Wait2 = 800;

void setup() {

Serial.begin(9600);
lcd.begin(16,2);
pinMode(sensor, INPUT);
pinMode(relay, OUTPUT);
  lcd.setCursor(0, 0);
  lcd.print("     Counted:"); 
}

void loop() {  

if (digitalRead(sensor) == HIGH) {
  delay(Wait1);
  digitalWrite(relay, HIGH);
  delay(HoldTime);
    lcd.setCursor(13,0);
  lcd.print(count++);
    Serial.println(count);
    digitalWrite(relay, LOW);
  delay(Wait2);
  }

if(count > Limit){
digitalWrite(relay, LOW);
  lcd.setCursor(0,1);
    lcd.print("Empty & Reset");
    while(count > Limit);

}

}

Any Ideas?
Thanks in advanced!

2

The displayed results are correct, and differ by one, exactly as coded and expected.

  lcd.print(count++);
    Serial.println(count);
3 
  lcd.print(count);
    Serial.println(count++);
4

Thank you @LarryD!

That worked along with changing:

int count=0;

to:

int count=1;

Cheers!

5

Try this…

6

@lastchancename Yup! that worked with the posted code. Only need to change one line as opposed to 3 lines. Odd I couldn't find this solution elsewhere... I've been searching for hours and within 20-30 mins of posting on the forum. Voila!!

Thanks again!

7

@lastchancename I spoke too soon.
I did have to make some more code changes for the "Limit" function to work with the displayed counts.

if(count > Limit -1){
digitalWrite(relay, LOW);
  lcd.setCursor(0,1);
    lcd.print("Empty & Reset");
    while(count > Limit -1);
8

Final woking code in case someone else is having the same issue:

#include <LiquidCrystal.h>
#include <EEPROM.h>

LiquidCrystal lcd(13,12,11,10,9,8);
const long Limit = 5;
int count=0;
int relay = 3;
int sensor = 5;
const long HoldTime = 1800;
const long Wait1 = 600;
const long Wait2 = 800;

void setup() {

Serial.begin(9600);
lcd.begin(16,2);
pinMode(sensor, INPUT);
pinMode(relay, OUTPUT);
  lcd.setCursor(0, 0);
  lcd.print("     Counted:   ");
  lcd.setCursor(0, 2);
  lcd.print("                ");
  delay(500);
}

void loop() {  

if (digitalRead(sensor) == HIGH) {
  delay(Wait1);
  digitalWrite(relay, HIGH);
  delay(HoldTime);
    lcd.setCursor(13,0);
  lcd.print(++count);
    Serial.println(count);
    digitalWrite(relay, LOW);
  delay(Wait2);
  }

if(count > Limit -1){
digitalWrite(relay, LOW);
  lcd.setCursor(0,1);
    lcd.print("Empty & Reset");
  while(count > Limit -1);
   }
}
9

fixed the count limit issue with this:

if(count >= Limit){
digitalWrite(relay, LOW);
  lcd.setCursor(0,1);
    lcd.print("Empty & Reset");
  while(count >= Limit);
10

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