कला
सुन्दरता र कल्याण
हस्तकला
संस्कृति र इतिहास
मनोरञ्जन
वातावरण
खाना र पेय
रिभर्स इन्जिनियरिङ
विज्ञान
खेलकुद
प्रविधि
पहिर्न मिल्ने
Building a Carbon Monoxide Detector
Ed

सिर्जनाकर्ता

Ed

13. जुलाई 2026FI
६०
०
०
०
०

Building a Carbon Monoxide Detector

Build a circuit that senses carbon monoxide (CO) — the invisible, odourless gas from any incomplete combustion — and raises an alarm when it rises. An MQ-7 sensor gives the Arduino a reading that climbs with CO; the code compares it to a clean-air baseline and triggers a buzzer and red LED. A great way to learn gas sensing — but read the safety note: this is a demonstration, NOT a certified life-safety CO alarm.

मध्यम
1-2 hours

निर्देशनहरू

1

Wire the sensor, buzzer and LED

On the breadboard: MQ-7 VCC to Arduino 5V, GND to GND, and its analog output (AOUT) to Arduino A0. Active buzzer + to pin 8, - to GND. Red LED anode to pin 7 through a 330 Ω resistor, cathode to GND.

यस चरणका सामग्री:

Arduino Uno R3Arduino Uno R31 टुक्रा
Carbon Monoxide Sensor - MQ-7Carbon Monoxide Sensor - MQ-71 टुक्रा
सक्रिय बजर मोड्युलसक्रिय बजर मोड्युल1 टुक्रा
LED - Basic 5mmLED - Basic 5mm1 टुक्रा
Resistor 330 Ohm 1/6 Watt PTH - 20 packResistor 330 Ohm 1/6 Watt PTH - 20 pack1 टुक्रा
BreadboardBreadboard1 टुक्रा
Jumper Wires (Male-to-Male)Jumper Wires (Male-to-Male)1 प्याक
2

Connect and open the IDE

Plug the Arduino into your computer with the USB cable, open the Arduino IDE, and select Arduino Uno and its serial port.

यस चरणका सामग्री:

USB-B CableUSB-B Cable1 टुक्रा

चाहिने औजार:

Arduino IDE भएको कम्प्युटरArduino IDE भएको कम्प्युटर
3

Upload the detector sketch

Paste this sketch and upload. It warms the sensor for two minutes, records a clean-air baseline, then sounds the buzzer and lights the LED whenever the reading climbs above that baseline.

co_detector.inoarduino
// Carbon monoxide INDICATOR using an MQ-7 sensor.
// NOT a certified life-safety alarm - see the blueprint's safety note.
// MQ-7 analog output on A0; buzzer on pin 8; red warning LED on pin 7.

const int MQ7_PIN = A0;
const int BUZZER_PIN = 8;
const int LED_PIN = 7;

int cleanAirValue = 0;          // baseline, measured at startup
const int ALARM_MARGIN = 150;   // how far above baseline triggers the alarm

void setup() {
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  Serial.begin(9600);

  Serial.println("Warming up the MQ-7 (2 min) in clean air...");
  delay(120000);                // 2-minute warm-up
  cleanAirValue = analogRead(MQ7_PIN);
  Serial.print("Clean-air baseline: ");
  Serial.println(cleanAirValue);
}

void loop() {
  int reading = analogRead(MQ7_PIN);
  Serial.println(reading);

  if (reading > cleanAirValue + ALARM_MARGIN) {
    digitalWrite(LED_PIN, HIGH);      // CO above baseline -> alarm
    digitalWrite(BUZZER_PIN, HIGH);
  } else {
    digitalWrite(LED_PIN, LOW);
    digitalWrite(BUZZER_PIN, LOW);
  }
  delay(500);
}
4

Warm up, baseline and test

Power it in fresh air and let the 2-minute warm-up set the clean-air baseline (a brand-new MQ-7 also needs a longer 24–48 h burn-in before its readings settle). Then hold a small CO source nearby in a ventilated room — the smoke from a just-blown-out match works — and the buzzer and LED should trigger. Change ALARM_MARGIN to make it more or less sensitive.

5

Important safety limits

This is a LEARNING project and, at best, a supplementary indicator — it is NOT a certified life-safety device. A hobby MQ-7 gives a relative reading, not a calibrated ppm; it drifts over time and needs regular re-baselining, and it also responds to smoke and other gases. Carbon monoxide is invisible, odourless and can be fatal: for real protection always use a UL- or EN-certified CO alarm. Never rely on this circuit to keep anyone safe.

सामग्री

8

आवश्यक उपकरणहरू

2
अनुमानित जम्मा
बनाउनेले किनेको कुरा। मूल्य नदेखिएका सामग्री तपाईंले जहाँबाट किन्नुहुन्छ त्यहीँबाट पाइन्छ।
$56.26

सम्बन्धित ब्लुप्रिन्ट

यी ब्लुप्रिन्टहरूले ज्ञान साझा गर्छन् — प्रविधि, सामग्री वा सिद्धान्त

Building an Ultrasonic Parking Sensor

Building an Ultrasonic Parking Sensor

Ed द्वाराFI

डिजिटल

४०
०
०
०
०
०
Blinking LED — Your First Arduino Project
BLUEPRINT NFT

Blinking LED — Your First Arduino Project

Admiral OOM द्वाराNO

डिजिटल

५१५
२
१
७
०
०

CC0 सार्वजनिक डोमेन

यो ब्लुप्रिन्ट CC0 अन्तर्गत जारी गरिएको छ। तपाईं अनुमति नसोधी प्रतिलिपि, परिमार्जन, वितरण र प्रयोग गर्न सक्नुहुन्छ।

ब्लुप्रिन्ट मार्फत उत्पादनहरू किनेर सिर्जनाकर्तालाई सहयोग गर्नुहोस् सिर्जनाकर्ता कमिसन विक्रेताले तोकेको, वा यो ब्लुप्रिन्टको नयाँ संस्करण बनाउनुहोस् र आम्दानी बाँड्न आफ्नो ब्लुप्रिन्टमा जडानको रूपमा समावेश गर्नुहोस्।

छलफल

(0)

लग इन छलफलमा सामेल हुन

टिप्पणीहरू लोड गर्दै...