MQ-8 Hydrogen Gas Sensor H2 Detection Sensor

Informačná stránka o senzore MQ-8 Hydrogen Gas Sensor

Popis Senzor MQ-8 je modul detektora vodíka, ktorý sa používa na detekciu prítomnosti vodíka vo vzduchu.

Vlastnosti

Detekcia prítomnosti vodíka vo vzduchu

Vysoká citlivosť

Ľahká integrovateľnosť s ESPHome

Parametre

Napájacie napätie: 5V

Pracovná teplota: -10°C až 50°C

Rozsah detekcie: 100ppm až 10000ppm

Rozhranie: Analógový pin

ESPHome konfigurácia

sensor:
- platform: adc
pin: A0
name: "Koncentrácia vodíka"
update_interval: 60s
filters:
- calibrate_linear:
- 0.0 -> 0.0
- 1023.0 -> 10000.0 # Predpokladajme, že 1023 je maximálna hodnota ADC a 10000 je maximálna koncentrácia

Príkladový kód pre Arduino

#define ANALOG_PIN A0 // Analógový pin pre senzor

void setup() {
Serial.begin(9600);
}

void loop() {
int hodnotaSenzora = analogRead(ANALOG_PIN);
float koncentráciaVodíka = map(hodnotaSenzora, 0, 1023, 0, 10000); // Mapovanie hodnoty senzora na koncentráciu (predpokladajme, že 1023 je maximálna hodnota ADC a 10000 je maximálna koncentrácia)

Serial.print("Koncentrácia vodíka: ");
Serial.println(koncentráciaVodíka);

delay(1000); // Prispôsobte oneskorenie podľa potreby
}

Informačná stránka o senzore MQ-8

Popis Senzor MQ-8 je modul detektora vodíka, ktorý je schopný detekovať prítomnosť vodíka v ovzduší.

Vlastnosti

Detekcia vodíka

Integrovateľnosť s rôznymi platformami

Vysoká citlivosť

Nízka spotreba energie

Špecifikácie

Napájacie napätie: 5V

Pracovná teplota: -10°C až 50°C

Rozsah detekcie: 100ppm až 1000ppm

Rozhranie: Analogové

Príklady použitia Senzor MQ-8 sa často používa na detekciu vodíka v rôznych prostrediach, ako sú priemyselné prevádzky, skladovacie priestory a laboratóriá.

Príkladový kód pre Arduino

// Importovanie knižnice pre senzor MQ-8
#include 

// Definícia pinu
int pinA0 = A0; // Analógový pin

// Inicializácia senzora
MQ8 mq8(pinA0);
void setup() {
Serial.begin(9600); // Inicializácia komunikácie sériového portu
}

void loop() {
// Čítanie hodnôt z senzora
float ppm = mq8.read();

// Vypísanie hodnôt na sériový port
Serial.print("Hodnota vodíka (PPM): ");
Serial.println(ppm);

delay(1000); // Čakanie 1 sekundu
}

Príkladový kód pre ESPHome

# Example configuration entry

sensor:
- platform: adc
pin: A0
name: "Hydrogen Sensor"
update_interval: 30s
filters:
- lambda: return (pow(10, log10((0.12/x)*(5-x)/(5-0.12))/(-0.35)))
unit_of_measurement: "ppm"

MQ8 Senzor vodíka H2 Detekčný senzor

Vstupné napätie: DC 5V

Prúd: 150mA

Výstup DO: TTL 0 a 1 (0,1 a 5 V)

AO výstup: 0,1 – 0,3V

Kryštály: 11,0592 MHz

Prenosová rýchlosť: 9600

Vlastnosti modulu:

Vysoko kvalitný dizajn s dvojitým panelom s indikátormi napájania a pokynmi na výstup signálu TTL

Výstup TTL a výstup analógového signálu AO

Štyri otvory pre skrutky uľahčujúce polohovanie

Funkcie obnovy rýchlej odozvy

Stabilita dlhej životnosti a spoľahlivosť

Veľkosť: 35 * 23 * 27 mm / 1,37 * 0,9 * 1,06 ”

Modul snímača vodíka/H2 MQ-8

Prehľad

Tento senzorový modul má MQ-8 ako senzorový komponent a má zabudovaný ochranný odpor a nastaviteľný odpor. Plynový senzor MQ-8 je vysoko citlivý na vodík a menej citlivý na alkohol a výpary z varenia. Mohol by byť použitý v zariadeniach na detekciu úniku plynu v rodine a priemysle. Odpor citlivej zložky sa mení so zmenou koncentrácie cieľového plynu.

Vlastnosti

Nepretržitý analógový výstup

3-pinový blokovací konektor

Nízka cena a kompaktná veľkosť

Standard Working Condition

Symbol Parameter Name Technical Condition Remarks

VC Circuit voltage 5V±0.1 AC or DC

VH Heating voltage 5V±0.1 AC or DC

RL Load resistance 10Kohm

RH Heater resistance 31Kohm±5% Room temperature

PH Heating consumption Less than 800mW

Environment Condition

Symbol Parameter Name Technical Condition Remarks

TO Operating Temp. -10°C-50°C

TS Storage Temp. -20°C-70°C

RH Relative Humidity <95%

O2 Oxygen Concentration 21%(standard condition) Oxygen concentration can affect sensitivity Minimum value is 2%

Sensitivity Characteristics

Symbol Parameter Name Technical Condition Remarks

RS Sensor Resistance 10Kohm-60Kohm (1000ppm LPG) Detecting concentration Scope: 100-10000ppm H2

α (1000ppm/4000ppm H2) Concentration slope rate ≤0.6

Standard detecting Condition Temp.: 20°C±2°C VC: 5V±0.1

Humidity:65%±5% VH:5V±0.1

Preheating Time Over 24 hours

/*******************Demo for MQ-8 Gas Sensor Module V1.0*****************************

Contact: support[at]sandboxelectronics.com

Lisence: Attribution-NonCommercial-ShareAlike 3.0 Unported (CC BY-NC-SA 3.0)

Note: This piece of source code is supposed to be used as a demostration ONLY. More

sophisticated calibration is required for industrial field application.

Sandbox Electronics 2014-02-03

************************************************************************************/

/************************Hardware Related Macros************************************/

#define MQ_PIN (0) //define which analog input channel you are going to use

#define RL_VALUE (10) //define the load resistance on the board, in kilo ohms

#define RO_CLEAN_AIR_FACTOR (9.21) //RO_CLEAR_AIR_FACTOR=(Sensor resistance in clean air)/RO,

//which is derived from the chart in datasheet

/***********************Software Related Macros************************************/

#define CALIBARAION_SAMPLE_TIMES (50) //define how many samples you are going to take in the calibration phase

#define CALIBRATION_SAMPLE_INTERVAL (500) //define the time interal(in milisecond) between each samples in the

//cablibration phase

#define READ_SAMPLE_INTERVAL (50) //define how many samples you are going to take in normal operation

#define READ_SAMPLE_TIMES (5) //define the time interal(in milisecond) between each samples in

//normal operation

/**********************Application Related Macros**********************************/

#define GAS_H2 (0)

/*****************************Globals***********************************************/

float H2Curve[3] = {2.3, 0.93,-1.44}; //two points are taken from the curve in datasheet.

//with these two points, a line is formed which is “approximately equivalent”

//to the original curve.

//data format:{ x, y, slope}; point1: (lg200, lg8.5), point2: (lg10000, lg0.03)

float Ro = 10; //Ro is initialized to 10 kilo ohms

void setup()

{

Serial.begin(9600); //UART setup, baudrate = 9600bps

Serial.print(“Calibrating…
”);

Ro = MQCalibration(MQ_PIN); //Calibrating the sensor. Please make sure the sensor is in clean air

//when you perform the calibration

Serial.print(“Calibration is done… ”); Serial.print(“Ro=”); Serial.print(Ro); Serial.print(“kohm”); Serial.print(“ ”);

}

void loop()

{

Serial.print(“H2:”);
Serial.print(MQGetGasPercentage(MQRead(MQ_PIN)/Ro,GAS_H2) );
Serial.print( “ppm” );
Serial.print(“
”);

delay(200);

}

/****************** MQResistanceCalculation ****************************************

Input: raw_adc – raw value read from adc, which represents the voltage

Output: the calculated sensor resistance

Remarks: The sensor and the load resistor forms a voltage divider. Given the voltage

across the load resistor and its resistance, the resistance of the sensor

could be derived.

************************************************************************************/

float MQResistanceCalculation(int raw_adc)

{

return ( ((float)RL_VALUE*(1023-raw_adc)/raw_adc));

}

/***************************** MQCalibration ****************************************

Input: mq_pin – analog channel

Output: Ro of the sensor

Remarks: This function assumes that the sensor is in clean air. It use

MQResistanceCalculation to calculates the sensor resistance in clean air

and then divides it with RO_CLEAN_AIR_FACTOR. RO_CLEAN_AIR_FACTOR is about

10, which differs slightly between different sensors.

************************************************************************************/

float MQCalibration(int mq_pin)

{

int i;

float val=0;

for (i=0;i<CALIBARAION_SAMPLE_TIMES;i++) { //take multiple samples

val += MQResistanceCalculation(analogRead(mq_pin));

delay(CALIBRATION_SAMPLE_INTERVAL);

}

val = val/CALIBARAION_SAMPLE_TIMES; //calculate the average value

val = val/RO_CLEAN_AIR_FACTOR; //divided by RO_CLEAN_AIR_FACTOR yields the Ro

//according to the chart in the datasheet

return val;

}

/***************************** MQRead *********************************************

Input: mq_pin – analog channel

Output: Rs of the sensor

Remarks: This function use MQResistanceCalculation to caculate the sensor resistenc (Rs).

The Rs changes as the sensor is in the different consentration of the target

gas. The sample times and the time interval between samples could be configured

by changing the definition of the macros.

************************************************************************************/

float MQRead(int mq_pin)

{

int i;

float rs=0;

for (i=0;i<READ_SAMPLE_TIMES;i++) {

rs += MQResistanceCalculation(analogRead(mq_pin));

delay(READ_SAMPLE_INTERVAL);

}

rs = rs/READ_SAMPLE_TIMES;

return rs;

}

/***************************** MQGetGasPercentage **********************************

Input: rs_ro_ratio – Rs divided by Ro

gas_id – target gas type

Output: ppm of the target gas

Remarks: This function passes different curves to the MQGetPercentage function which

calculates the ppm (parts per million) of the target gas.

************************************************************************************/

int MQGetGasPercentage(float rs_ro_ratio, int gas_id)

{

if ( gas_id == GAS_H2) {

return MQGetPercentage(rs_ro_ratio,H2Curve);

}

return 0;

}

/***************************** MQGetPercentage **********************************

Input: rs_ro_ratio – Rs divided by Ro

pcurve – pointer to the curve of the target gas

Output: ppm of the target gas

Remarks: By using the slope and a point of the line. The x(logarithmic value of ppm)

of the line could be derived if y(rs_ro_ratio) is provided. As it is a

logarithmic coordinate, power of 10 is used to convert the result to non-logarithmic

value.

************************************************************************************/

int MQGetPercentage(float rs_ro_ratio, float *pcurve)

{

return (pow(10,( ((log(rs_ro_ratio)-pcurve[1])/pcurve[2]) + pcurve[0])));

}