{"product_id":"mq-7-carbon-monoxide-gas-sensor-module-for-arduino-esp32","title":"MQ-7 Carbon Monoxide Gas Sensor Module for Arduino \u0026 ESP32","description":"\u003ch1\u003eMQ-7 Carbon Monoxide Gas Sensor Module (5V Analog)\u003c\/h1\u003e\n\n\u003cp class=\"product-lede\"\u003eThe 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.\u003c\/p\u003e\n\n\u003ch2\u003eKey Specifications\u003c\/h2\u003e\n\u003ctable class=\"specs-table\"\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003cth\u003eDetection Gas\u003c\/th\u003e\n\u003ctd\u003eCarbon Monoxide (CO)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eDetection Range\u003c\/th\u003e\n\u003ctd\u003e20 – 200 ppm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eOperating Voltage\u003c\/th\u003e\n\u003ctd\u003e5 V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eHeater Voltage\u003c\/th\u003e\n\u003ctd\u003e5 V (high) \/ 1.4 V (low) cyclic\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003ePreheat Time\u003c\/th\u003e\n\u003ctd\u003e24 – 48 hours for full stability\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eResponse Time\u003c\/th\u003e\n\u003ctd\u003e\u0026lt; 10 s\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eOutput Type\u003c\/th\u003e\n\u003ctd\u003eAnalog 0–5 V (proportional to concentration)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhat You Can Build With This\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSimple CO Alert Indicator:\u003c\/strong\u003e Use an Arduino Uno to light green, yellow, or red LEDs and sound a buzzer based on CO levels.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWi‑Fi CO Monitor:\u003c\/strong\u003e Connect to ESP8266 and send real‑time readings and Telegram alerts when thresholds are breached.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRaspberry Pi Air Station:\u003c\/strong\u003e Build an MQTT‑based home dashboard with logging, fan control, and email alerts using an MCP3008 ADC.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePollution Science Model:\u003c\/strong\u003e Make a portable CO detector with a transistor driver and alarm for CBSE Class 12 physics or ATL Tinkering Lab.\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/kit-vehicle-cabin-air-monitor-kit\"\u003e\n\u003cstrong\u003eSmart Vehicle Cabin Safety:\u003c\/strong\u003e Develop an IoT‑enabled CO monitor for driver safety as a B.Tech final‑year project or Smart India Hackathon solution.\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003ctable class=\"compat-table\"\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003ePlatform\u003c\/th\u003e\n\u003cth\u003eCompatible\u003c\/th\u003e\n\u003cth\u003eConnection\u003c\/th\u003e\n\u003cth\u003eLibrary \/ Method\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eArduino Uno R3\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eAnalog pin A0\u003c\/td\u003e\n\u003ctd\u003eanalogRead(A0)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eArduino Nano\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eAnalog pin A0\u003c\/td\u003e\n\u003ctd\u003eanalogRead(A0)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eArduino Mega 2560\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eAny analog pin (A0–A15)\u003c\/td\u003e\n\u003ctd\u003eanalogRead(pin)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eESP8266 NodeMCU\u003c\/td\u003e\n\u003ctd\u003eYes with condition\u003c\/td\u003e\n\u003ctd\u003ePin A0 (via 5V to 1V voltage divider)\u003c\/td\u003e\n\u003ctd\u003eanalogRead(A0)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eESP32 Dev Board\u003c\/td\u003e\n\u003ctd\u003eYes with condition\u003c\/td\u003e\n\u003ctd\u003eAny ADC1 pin (e.g., GPIO34) with level shifter\u003c\/td\u003e\n\u003ctd\u003eanalogRead(pin)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRaspberry Pi Pico\u003c\/td\u003e\n\u003ctd\u003eYes with condition\u003c\/td\u003e\n\u003ctd\u003eADC0 (GP26) with 3.3 V level shifter\u003c\/td\u003e\n\u003ctd\u003emachine.ADC(26) in MicroPython\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRaspberry Pi 4 \/ 5\u003c\/td\u003e\n\u003ctd\u003eYes with condition\u003c\/td\u003e\n\u003ctd\u003eVia MCP3008 ADC on SPI (CE0, MOSI, MISO, SCLK)\u003c\/td\u003e\n\u003ctd\u003espidev library in Python\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWiring and Interface Notes\u003c\/h2\u003e\n\u003cp\u003eConnect 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.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cdiv class=\"faq\"\u003e\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003ch3\u003eWhy does the sensor need 24‑48 hours of preheating?\u003c\/h3\u003e\n    \u003cp\u003eThe 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.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003ch3\u003eCan I use the MQ-7 to detect methane or LPG?\u003c\/h3\u003e\n    \u003cp\u003eThis sensor is optimised for CO; it has limited cross‑sensitivity. For methane or LPG, choose an MQ-4 or MQ-5 sensor instead.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@graph\": [\n    {\n      \"@type\": \"Product\",\n      \"@id\": \"https:\/\/compoden.in\/products\/mq-7-carbon-monoxide-gas-sensor-module-for-arduino-esp32#product\",\n      \"name\": \"MQ-7 Carbon Monoxide Gas Sensor Module (5V Analog)\",\n      \"description\": \"Buy MQ-7 CO gas sensor module for Arduino \u0026 ESP32. Detects 20-200ppm carbon monoxide, analog output, 5V heater. Fast response, long life. 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