MQ-7 module carbon dioxide gas sensitive sensor detection alarm module

Module application:
Carbon dioxide detection devices for family and environment.Suitable for detection of carbon monoxide, gas, etc.
Module characteristics:
1. Using high -quality double -faced design, with power supply and TTL signal output indication;
2. With DO switch signal (TTL) output and AO analog signal output;
3. The valid signal of the TTL output is low level.In
4. The output voltage of the analog quantity, the higher the concentration, the higher the voltage.
5. There is a good sensitivity to carbon monoxide detection.
6. There are four screw holes for easy positioning;
7. Product Dimensions: 32 (L)*20 (W)*22 (H)
8. Have long -term service life and reliable stability
9. Quick response recovery characteristics

Electricity:
Input voltage: DC5V power consumption (current): 150mA
Do output: TTL number 0 and 1 (0.1 and 5V)
AO output: 0.1-0.3V (relatively pollution-free), the highest concentration voltage is about 4V
Special reminder: After the sensor is powered on, it needs to be preheated about 20s, and the measured data is stable. The sensor fever is normal because there is electric heating wire inside, and if it is hot, it is not normal.

Test program:

Implement function: This version of the supporting test program

Use chip: AT89S52

Crystal: 11.0592MHz

Potter rate: 9600

Compile environment: keil

[Disclaimer] This program is only used for learning and reference. Please indicate copyright and author information!

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Note: 1. When the measurement concentration is greater than the set concentration, the output of the single -chip machine IO port is low

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#include // library file

#Define uchar unsigned char //

#Define UINT UNSIGNED Int //

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

I/O definition

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sbit LED = P1^0; // Define the first place (ie P1.0) of the P1 port of the single -chip machine as the indicator end

sbit double = p2^0; // Define the first place (ie P2.0) of the P2 port of the single -chip microcomputer as the input terminal of the sensor

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

Delay function

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void delay () // delay program

{{

uchar m, n, s;

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

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

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

}

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

Main function

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void main ()

{{

While (1) // Infinite cycle

{{

LED = 1; // Out off P1.0 port

if (double == 0) // When the concentration is higher than the set value, the execution condition function

{{

delay (); // Delayed anti -interference

if (double == 0) // When the concentration is higher than the set value, the execution condition function

{{

LED = 0; // Light P1.0 port

}

}

}

}

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

Finish

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