MQ-2 Cảm biến phát hiện khí ga, khói, khí dễ cháy.

Module Applications:
can be used for home and factory gas leakage monitoring devices, suitable for the detection of gas, butane, propane, methane, smog;
module Features:
1, using high-quality dual-panel design, with power indicator and TTL signal output instructions;
2, with DO switching signal (TTL) output and analog output AO;
3, TTL output valid signal is low. (When the output low signal light can be directly connected microcontroller or relay modules)
4, analog output voltage with the higher concentration the higher the voltage.
5, liquefied petroleum gas, natural gas, city gas, smoke have better sensitivity.
6, there are four screw holes for easy positioning;
7. Product dimensions: 32 (L) * 20 (W) * 22 (H)
8, has a long life and reliable stability
9, rapid response recovery characteristics

Electrical performance: Input voltage: DC5V Power (current): 150mA DO output: TTL digital 0 and 1 (0.1 and 5V)

AO Output: 0.1-0.3V (relatively clean), the highest concentration voltage around 4V

Special note: Sensors Power, the need to preheat for about 20S, measured data becomes stable, heat sensor is a normal phenomenon, because the inside with an electric wire, if not normal hot.

Wiring way: 1, VCC: positive power supply (5V) 2, GND: power supply is negative3, DO: TTL switching signal output 4, AO: Analog output

Test program:

Function: This version supporting test procedures

Using a Chip: AT89S52

Crystal: 11.0592MHZ

Baud Rate: 9600

Compiler Environment: Keil

[Statement] This procedure is used only for study and reference, please indicate the copyright and author information!

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Note: 1, when the measured concentration is greater than the set concentration, single-chip IO port output low

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#include // library

#define uchar unsigned char // unsigned char macro definition

#define uint unsigned int // macros unsigned integer

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I / O definitions

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sbit LED = P1 ^ 0; // definition of the microcontroller P1 port of the first one (ie P1.0) to indicate the end

sbit DOUT = P2 ^ 0; // definition of the microcontroller P2 port first one (ie P2.0) as an input sensor

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Delay function

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void delay () // delay procedure

{

uchar m, n, s;

for (m = 20; m> 0; m--)

for (n = 20; n> 0; n--)

for (s = 248; s> 0; s--);

}

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The main function

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void main ()

{

while (1) // infinite loop

{

LED = 1; // Off P1.0 mouth lights

if (DOUT == 0) // When the concentration is higher than the set value, the implementation of the Con

{

delay (); // delay interference

When if (DOUT == 0) // determine concentrations higher than the set value, the implementation of the Con

{

LED = 0; // P1.0 port lights lit

}

}

}

}

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End

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