main.cpp

00001 #include "mbed.h"
00002 #include "MQ7.h"
00003 
00004 DigitalOut led1(LED1);
00005 DigitalOut led2(LED2);
00006 DigitalOut led3(LED3);
00007 MQ7 sensor(p21, p22); // ALR, HSW
00008 
00009 int main() {
00010     
00011     while(1) {
00012         led1 = 0;
00013         led2 = 0;
00014         led3 = 0;
00015         
00016         // Purge the device for 60 sec
00017         sensor.setHeat(1.0f); // supply full 5V to module
00018         led1 = 1; // Turn on only LED1 during Purge phase
00019         for (int i = 0; i < 60; i++){
00020             wait(1); // wait 60 seconds
00021         }
00022         
00023         // Purge complete
00024         // Sense the device for 90 sec 
00025         sensor.setHeat(0.28f); // supply 1.4V to module
00026         led1 = 0; 
00027         led2 = 1; // Turn on only LED2 during Sense phase
00028         for (int i = 0; i < 90; i++){
00029             if (sensor.getAlarm() == 1)
00030                 led3 = 1; // Turn on LED3 if CO gas levels reached
00031             wait(1); 
00032         }
00033         // Sense complete, start over
00034         wait(0.5);
00035     }
00036 }