Alcohol sensor beep

Projects Programming
1

I've been trying to figure out how to make my Arduino nano use a buzzer to beep when the sensor value reaches 1023 but I haven't been able to get it set up. Any help would be appreciated. Here's my code:

// Include the library code:
#include <LiquidCrystal.h>

// Initialize the library with the numbers of the 
// UNO interface pins. 
// Syntax: LiquidCrystal(rs, enable, d4, d5, d6, d7) 
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

#define buzzer 13
//#define MQ3pin 0

float sensorValue;  //variable to store sensor value

void setup() {
  lcd.begin(20, 4);
    pinMode(13, OUTPUT);
	//lcd.print("MQ3 warming up!");
	//delay(20000); // allow the MQ3 to warm up
	//if (sensorValue = 1023) {tone( buzzer, 3000);}
  //if {digitalWrite(ledPin, {tone( buzzer, 3000);});};
  //else { };
}

void loop() {
	sensorValue = analogRead(0); // read analog input pin 0
  if (analogRead > 1022)
  lcd.setCursor (0,0);
  lcd.print ("250-510: no alc");
  lcd.setCursor (0,1);
  lcd.print ("511-1022 Mod alc");
  lcd.setCursor (0,2);
  lcd.print ("flash 1023: high alc");

  lcd.setCursor (0,3);
	lcd.print("Alc level: ");
	lcd.print(sensorValue);

	delay(2000); // wait 2s for next reading
  lcd.clear();
}
2 
 if (analogRead > 1022)
  lcd.setCursor (0,0);
  lcd.print ("250-510: no alc");
  lcd.setCursor (0,1);
  lcd.print ("511-1022 Mod alc");
  lcd.setCursor (0,2);
  lcd.print ("flash 1023: high alc");

  lcd.setCursor (0,3);
	lcd.print("Alc level: ");
	lcd.print(sensorValue);

	delay(2000); // wait 2s for next reading
  lcd.clear();

Oops, on several fronts.

  • if(analogRead) should be if(sensorValue), as that's where the result of the analogRead() was stored.
  • your if case must begin and end with {}. as it is, only the lcd.setCursor() statement is conditional.
    try that. You may find lowering your threshold to, for example, 1020, is beneficial as well.
3

Did you want to acknowledge a value below 250? As it is, it will seem like your device doesn't work.

4

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.