sensor MQ-2 smoke gas sensor module methane liquefied flammable gas

Weight: 7.4 grams a

Sensor MQ-2 Introduction:
MQ-2 gas sensor sensitive material used in the clean air, low conductivity tin oxide (SnO2). When there is an environment in which the combustible gas sensor, conductivity sensor with increasing concentration of combustible gases in air increases. Use simple circuit can convert the change in conductivity of the gas concentration corresponding to the output signal. MQ-2 gas sensor for high gas, propane, hydrogen sensitivity of detection of natural gas and other flammable vapors are also very satisfactory. The sensor can detect a variety of combustible gas, it is a low-cost sensor suitable for a variety of applications.

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

Electrical properties:
Input voltage: DC5V power (current): 150mA
DO output: TTL digital 0 and 1 (0.1 and 5V)
AO Output: about 0.1-0.3V (relatively clean), the highest concentration voltage 4V
Special note: When the sensor is powered, need to warm about 20S, measured data becomes stable, heat sensor is a normal phenomenon, because the internal heating wire, hot if not normal.

test program:

Function: This version of the test program supporting
Use 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!
************************************************** ******************* /
/ ************************************************* *******************
Note: 1, when the measured concentration is greater than the set density, single-chip IO port output low
************************************************** ******************* /
# Include // library files
#define uchar unsigned char // macro definition unsigned char
#define uint unsigned int // macro definition unsigned int
 
/ ************************************************* *******************
I / O definitions
************************************************** ******************* /
sbit LED = P1 ^ 0; // define microcontroller P1 port of the first one (ie P1.0) to indicate the end
sbit DOUT = P2 ^ 0; // define the microcontroller P2 port first one (ie P2.0) as an input sensor
/ ************************************************* *******************
Delay function
************************************************** ******************* /
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--);
}
/ ************************************************* *******************
The main function
************************************************** ******************* /
void main ()
{
while (1) // infinite loop
{
LED = 1; // off P1.0 port 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 the concentration higher than the set value, the implementation of the Con
{
LED = 0; // P1.0 port lights lit
}
}
}
}
/ ************************************************* *******************
End