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MQ-7 Carbon Monoxide Gas Sensor Module for Arduino & ESP32
Rs. 170.00
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MQ-7 Carbon Monoxide Gas Sensor Module (5V Analog)
The MQ-7 gas sensor module detects 20-200 ppm carbon monoxide via analog output, ideal for air quality monitors and safety alarms with Arduino, ESP32, or Raspberry Pi.
Key Specifications
| Detection Gas | Carbon Monoxide (CO) |
|---|---|
| Detection Range | 20 – 200 ppm |
| Operating Voltage | 5 V DC |
| Heater Voltage | 5 V (high) / 1.4 V (low) cyclic |
| Preheat Time | 24 – 48 hours for full stability |
| Response Time | < 10 s |
| Output Type | Analog 0–5 V (proportional to concentration) |
What You Can Build With This
- Simple CO Alert Indicator: Use an Arduino Uno to light green, yellow, or red LEDs and sound a buzzer based on CO levels.
- Wi‑Fi CO Monitor: Connect to ESP8266 and send real‑time readings and Telegram alerts when thresholds are breached.
- Raspberry Pi Air Station: Build an MQTT‑based home dashboard with logging, fan control, and email alerts using an MCP3008 ADC.
- Pollution Science Model: Make a portable CO detector with a transistor driver and alarm for CBSE Class 12 physics or ATL Tinkering Lab.
- Smart Vehicle Cabin Safety: Develop an IoT‑enabled CO monitor for driver safety as a B.Tech final‑year project or Smart India Hackathon solution.
Compatibility
| Platform | Compatible | Connection | Library / Method |
|---|---|---|---|
| Arduino Uno R3 | Yes | Analog pin A0 | analogRead(A0) |
| Arduino Nano | Yes | Analog pin A0 | analogRead(A0) |
| Arduino Mega 2560 | Yes | Any analog pin (A0–A15) | analogRead(pin) |
| ESP8266 NodeMCU | Yes with condition | Pin A0 (via 5V to 1V voltage divider) | analogRead(A0) |
| ESP32 Dev Board | Yes with condition | Any ADC1 pin (e.g., GPIO34) with level shifter | analogRead(pin) |
| Raspberry Pi Pico | Yes with condition | ADC0 (GP26) with 3.3 V level shifter | machine.ADC(26) in MicroPython |
| Raspberry Pi 4 / 5 | Yes with condition | Via MCP3008 ADC on SPI (CE0, MOSI, MISO, SCLK) | spidev library in Python |
Wiring and Interface Notes
Connect VCC to 5 V and GND to ground; the analog output (AO) goes to your microcontroller’s ADC pin. For 3.3 V boards like ESP32 or Pico, use a pair of resistors (e.g., 10kΩ + 20kΩ) as a voltage divider to bring 5 V down to 3.3 V. Let the sensor preheat for at least 24 hours before taking measurements for stable baseline values.
Frequently Asked Questions
Why does the sensor need 24‑48 hours of preheating?
The MQ-7’s tin‑dioxide sensing layer must reach chemical equilibrium in clean air; this long burn‑in ensures accurate, drift‑free carbon monoxide readings.
Can I use the MQ-7 to detect methane or LPG?
This sensor is optimised for CO; it has limited cross‑sensitivity. For methane or LPG, choose an MQ-4 or MQ-5 sensor instead.
What you can build with this
CO2 Monitor for Meeting Rooms - Arduino Kit
Classroom CO2 Monitor Pro Kit with Arduino Uno + Sensor
Office CO2 Tracker Pro Kit with Arduino Uno + DHT22
Meeting Room Ventilation Monitor Pro Kit with Arduino Uno + DHT22
CO2 Plant Respiration Logger Kit with Arduino Uno + Sensor
CO2 Room Ventilation Alert Kit with Arduino Uno + Sensor
Indoor CO2 Dashboard Kit with Arduino Uno + DHT22
Arduino CO2 Monitor Kit: MH-Z19 Sensor, OLED & Ventilation Alert
Greenhouse CO2 Enrichment Controller Kit with Arduino Uno + Sensor
Arduino Kit for Mushroom Fruiting Automation: DHT22 & CO2
Mushroom Fruiting Body Trigger Variant 18 Kit with Arduino Uno + DHT22
Containerised MQTT Broker and Sensor Dashboard
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items