Hi,
I am making a counter that adds 124 every second and displays the updated number on an LCD. However, at some point it starts to show negative numbers. What would be the cause of this?
#include <LiquidCrystal.h>
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
// constants won't change. Used here to set a pin number:
const int ledPin = 13;// the number of the LED pin
// Variables will change:
int ledState = LOW; // ledState used to set the LED
// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long previousMillis = 0; // will store last time LED was updated
// constants won't change:
const long interval = 1000; // interval at which to blink (milliseconds)
int money = 0;
void setup() {
// set the digital pin as output:
pinMode(ledPin, OUTPUT);
Serial.begin(9600);
lcd.begin(16, 2);
lcd.print("$");
}
void loop() {
// here is where you'd put code that needs to be running all the time.
// check to see if it's time to blink the LED; that is, if the difference
// between the current time and last time you blinked the LED is bigger than
// the interval at which you want to blink the LED.
unsigned long currentMillis = millis();
lcd.setCursor(2, 0);
lcd.print(0);
if (currentMillis - previousMillis >= interval) {
// save the last time you blinked the LED
previousMillis = currentMillis;
// if the LED is off turn it on and vice-versa:
if (ledState == LOW) {
ledState = HIGH;
} else {
ledState = LOW;
}
money = money + 124;
//Serial.println('
- ' ' + money);
lcd.setCursor(2, 0);
lcd.print(money);}
delay(1000);
// set the LED with the ledState of the variable:
digitalWrite(ledPin, ledState);
}