{"product_id":"mq-3b-mq-7b-mq-2-mq-3-mq-4-mq-5-mq-6-mq-7-mq-8-mq-9-mq-135-detection-smoke-methane-liquefied-gas-sensor-module-2","title":"MQ-3B MQ-7B MQ-2 MQ-3 MQ-4 MQ-5 MQ-6 MQ-7 MQ-8 MQ-9 MQ-135  Detection Smoke methane liquefied Gas Sensor Module","description":"\u003ch1\u003eSPECIFICATIONS\u003c\/h1\u003e\u003cp\u003e\u003cspan\u003eBrand Name\u003c\/span\u003e: \u003cspan style=\"color:#333\"\u003eSZFYDOSH\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003e\u003cspan\u003eChoice\u003c\/span\u003e: \u003cspan style=\"color:#333\"\u003eyes\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003e\u003cspan\u003eMaterial\u003c\/span\u003e: \u003cspan style=\"color:#333\"\u003eMixture\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003e\u003cspan\u003eModel Number\u003c\/span\u003e: \u003cspan style=\"color:#333\"\u003eMQ\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003e\u003cspan\u003eOrigin\u003c\/span\u003e: \u003cspan style=\"color:#333\"\u003eMainland China\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003e\u003cspan\u003eOutput\u003c\/span\u003e: \u003cspan style=\"color:#333\"\u003eDigital Sensor\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003e\u003cspan\u003eTheory\u003c\/span\u003e: \u003cspan style=\"color:#333\"\u003eOther\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003e\u003cspan\u003eType\u003c\/span\u003e: \u003cspan style=\"color:#333\"\u003eGas Sensor\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003e\u003cspan\u003eUse\u003c\/span\u003e: \u003cspan style=\"color:#333\"\u003eGas Sensor\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003e\u003cspan\u003eis_customized\u003c\/span\u003e: \u003cspan style=\"color:#333\"\u003eYes\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003e\u003cspan\u003esemi_Choice\u003c\/span\u003e: \u003cspan style=\"color:#333\"\u003eyes\u003c\/span\u003e\u003c\/p\u003e\u003cdiv class=\"detailmodule_html\"\u003e\u003cdiv class=\"detail-desc-decorate-richtext\"\u003e\n\u003cp\u003e\u003cspan style=\"font-size:18px\"\u003eMQ-2 MQ-3 MQ-4 MQ-5 MQ-6 MQ-7 MQ-8 MQ-9 MQ-135 Probe Gas sensor\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eMQ-2 MQ-3 MQ-4 MQ-5 MQ-6 MQ-7 MQ-8 MQ-9 MQ-135 Detection Smoke methane liquefied Gas Sensor Module for Arduino Starter DIY Kit\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv style=\"font-family:arial, helvetica, sans-serif;font-size:13px;font-weight:normal;color:rgb(0, 0, 0);background-color:rgb(255, 255, 255);border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style=\"font-size:22px\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eThe gas-sensing material used in the MQ-2 gas sensor is tin oxide (SnO2) with a low conductivity in clean air. When there is a combustible gas in the environment in which the sensor is present, the conductivity of the sensor increases as the concentration of combustible gas in the air increases. The change in conductivity can be converted to an output signal corresponding to the gas concentration using a simple circuit. The MQ-2 gas sensor is highly sensitive to liquefied gas, propane and hydrogen, and is ideal for the detection of natural gas and other combustible vapors. This sensor can detect a variety of flammable gases, is a variety of applications for low-cost sensors.\u003c\/span\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family:arial, helvetica, sans-serif;font-size:13px;font-weight:normal;color:rgb(0, 0, 0);background-color:rgb(255, 255, 255);border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family:arial, helvetica, sans-serif;font-size:13px;font-weight:normal;color:rgb(0, 0, 0);background-color:rgb(255, 255, 255);border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eModule Application:\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eCan be used for home and factory gas leak monitoring device, suitable for liquefied gas, butane, propane, methane, smoke and other detection;\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eModule Features:\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e1, the use of high-quality double-panel design, with power indicator and TTL signal output instructions;\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e2, with DO switch signal (TTL) output and AO analog signal output;\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e3, TTL output valid signal is low. (When the output low signal lights, can be directly connected to the microcontroller or relay module)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e4, the analog output voltage with the higher the higher the voltage the higher the voltage.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e5, the liquefied petroleum gas, natural gas, city gas, smoke has a better sensitivity.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e6, there are four screw holes to facilitate positioning;\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e7, product dimensions: 32 (L) * 20 (W) * 22 (H)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e8, with long service life and reliable stability\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e9, fast response to recovery features\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eElectrical performance:\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eInput voltage: DC5V Power consumption (current): 150mA\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eDO output: TTL digital 0 and 1 (0.1 and 5V)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eAO output: 0.1-0.3V (relatively no pollution), the maximum concentration of about 4V voltage\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eSpecial reminder: the sensor power, the need to preheat 20S or so, the measured data was stable, the sensor fever is a normal phenomenon, because the internal electric wire, if the hot is not normal.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eWiring:\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e1, VCC: then the power supply positive (5V)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e2, GND: Connect the power supply negative\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e3, DO: TTL switch signal output\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e4, AO: analog signal output\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003etest program:\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eImplementation of the function: This version of supporting test procedures\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eUse the chip: AT89S52\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eCrystal: 11.0592MHZ\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eBaud rate: 9600\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eCompiler environment: Keil\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e【Statement】 This procedure is only used for learning and reference, please specify the copyright and author information!\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e************************************************** ******************* \/\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e\/ ************************************************* *******************\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eDescription: 1, when the measured concentration is greater than the set concentration, the microcontroller IO output low\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e************************************************** ******************* \/\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e# Include \/\/ library file\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e#define uchar unsigned char \/\/ macro defines unsigned character\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e#define uint unsigned int \/\/ macro defines unsigned integer\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e\/ ************************************************* *******************\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eI \/ O definition\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e************************************************** ******************* \/\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eSbit LED = P1 ^ 0; \/ \/ define the first bit of P1 port P1 (P1.0) as the indicator\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eSbit DOUT = P2 ^ 0; \/ \/ define the first bit of the microcontroller P2 port (ie P2.0) for the sensor input\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e\/ ************************************************* *******************\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eDelay function\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e************************************************** ******************* \/\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eVoid delay () \/\/ delay program\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e{\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eUchar m, n, s;\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eFor (m = 20; m\u0026gt; 0; m--)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eFor (n = 20; n\u0026gt; 0; n--)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eFor (s = 248; s\u0026gt; 0; s--);\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e}\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e\/ ************************************************* *******************\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eMain function\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e************************************************** ******************* \/\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eVoid main ()\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e{\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eWhile (1) \/\/ infinite loop\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e{\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eLED = 1; \/\/ off P1.0 port light\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eIf (DOUT == 0) \/\/ When the concentration is higher than the set value, execute the condition function\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e{\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eDelay (); \/ \/ delay anti-interference\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eIf (DOUT == 0) \/\/ When the concentration is higher than the set value, execute the condition function\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e{\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eLED = 0; \/\/ light P1.0 port light\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e}\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e}\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e}\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e}\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e\/ ************************************************* *******************\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003eEnd\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"border:0px;margin:0px;margin-bottom:0px;margin-top:0px;margin-left:0px;margin-right:0px;padding:0px;padding-bottom:0px;padding-top:0px;padding-left:0px;padding-right:0px;box-sizing:content-box\"\u003e\u003cspan style='font-size:18px;font-family:\"Times New Roman\"'\u003e************************************************** ****************** \/\u003c\/span\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/ae01.alicdn.com\/kf\/S925878fcfa4540168576de6bdb33b0100.png\" slate-data-type=\"image\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style='font-size:20px;font-family:\"Times New Roman\"'\u003e\u003cstrong\u003e\u003cu\u003eProduct Introduction\u003c\/u\u003e\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style='font-family:\"Times New Roman\"'\u003eThe gas sensitive material used by MQ-7B carbon monoxide gas sensor is tin dioxide (Sn02) with low conductivity in clean air. The high and low temperature cycle detection method is adopted to detect carbon monoxide at low temperature (1.5V heating). The conductivity of the sensor increases with the increase of carbon monoxide gas concentration in the air. The high temperature (5.0V heating) cleans the stray gas adsorbed at low temperature. A simple circuit can be used to convert the change in conductivity into an output signal corresponding to the concentration of the gas.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style='font-family:\"Times New Roman\"'\u003eThe MQ-7B Carbon Monoxide gas sensor is highly sensitive to carbon monoxide and can detect a variety of carbon monoxide containing gases, making it a low-cost sensor suitable for a variety of applications.\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cp\u003e\u003cbr\u003e\u003cspan style='font-size:20px;font-family:\"Times New Roman\"'\u003e\u003cstrong\u003e\u003cu\u003eProduct Introduction\u003c\/u\u003e\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style='font-family:\"Times New Roman\"'\u003eThe gas-sensitive material used by the MQ-3B alcohol gas sensor is tin dioxide (SnO2), which has a low conductivity in clean air. When alcohol vapor exists in the environment of the alcohol sensor, the conductivity of the gas sensor increases with the increase of the alcohol gas concentration in the air. A simple circuit is used to convert the change in conductivity into an output signal corresponding to the concentration of the gas.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style='font-family:\"Times New Roman\"'\u003eMQ-3B semiconductor alcohol sensor has high sensitivity to alcohol and can resist the interference of gasoline, smoke and water vapor. The gas sensor can detect a variety of alcohol atmospheres, making it a low-cost sensor suitable for a variety of applications\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/ae01.alicdn.com\/kf\/S2e037f2953fe453b9c4e63396813873bm.jpg\" slate-data-type=\"image\"\u003e\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/div\u003e\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e","brand":"Yoeruyo","offers":[{"title":"MQ-8","offer_id":55441054269739,"sku":"14:496#MQ-8","price":7.7,"currency_code":"USD","in_stock":true},{"title":"MQ-9","offer_id":55441054302507,"sku":"14:365458#MQ-9","price":8.46,"currency_code":"USD","in_stock":true},{"title":"MQ-135","offer_id":55441054335275,"sku":"14:100013777#MQ-135","price":8.1,"currency_code":"USD","in_stock":true},{"title":"MQ-3B","offer_id":55441054368043,"sku":"14:200005536#MQ-3B","price":12.51,"currency_code":"USD","in_stock":true},{"title":"MQ-5","offer_id":55441054400811,"sku":"14:175#MQ-5","price":7.7,"currency_code":"USD","in_stock":true},{"title":"MQ-4","offer_id":55441054433579,"sku":"14:173#MQ-4","price":7.7,"currency_code":"USD","in_stock":true},{"title":"MQ-6","offer_id":55441054466347,"sku":"14:193#MQ-6","price":7.7,"currency_code":"USD","in_stock":true},{"title":"MQ-7","offer_id":55441054499115,"sku":"14:366#MQ-7","price":8.46,"currency_code":"USD","in_stock":true},{"title":"MQ-2","offer_id":55441054531883,"sku":"14:10#MQ-2","price":7.7,"currency_code":"USD","in_stock":true},{"title":"MQ-3","offer_id":55441054564651,"sku":"14:29#MQ-3","price":8.46,"currency_code":"USD","in_stock":true},{"title":"MQ-7B","offer_id":55441054597419,"sku":"14:200006154#MQ-7B","price":11.93,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1000\/5744\/8747\/files\/Sd41bd9ac026a4bad8421c234d7a3a7dec_2291fa42-a8eb-4bd1-84e9-ae993f7912ea.webp?v=1788748710","url":"https:\/\/yoeruyo.com\/products\/mq-3b-mq-7b-mq-2-mq-3-mq-4-mq-5-mq-6-mq-7-mq-8-mq-9-mq-135-detection-smoke-methane-liquefied-gas-sensor-module-2","provider":"Yoeruyo","version":"1.0","type":"link"}