Diff: MQ2.h

Revision:

1:323f72b59e99

Parent:

0:a5033edf6975

Child:

3:ed294e830904

--- a/MQ2.h	Thu Oct 05 11:33:31 2017 +0000
+++ b/MQ2.h	Thu Oct 05 12:03:38 2017 +0000
@@ -4,15 +4,15 @@
 #include "mbed.h"
 
 #define RL_VALUE                    5                                           //define the load resistance on the board, in kilo ohms
-#define RO_DEFAULT                  10 
-#define RO_CLEAN_AIR_FACTOR         9.83f 
-#define CALIBARAION_SAMPLE_TIMES    5
-#define CALIBRATION_SAMPLE_INTERVAL 50
-#define READ_SAMPLE_INTERVAL        50
-#define READ_SAMPLE_TIMES           5
+#define RO_DEFAULT                  10                                          //Ro is initialized to 10 kilo ohms
+#define RO_CLEAN_AIR_FACTOR         9.83f                                       //RO_CLEAR_AIR_FACTOR=(Sensor resistance in clean air)/RO, which is derived from the chart in datasheet
+#define CALIBARAION_SAMPLE_TIMES    5                                           //define how many samples you are going to take in the calibration phase
+#define CALIBRATION_SAMPLE_INTERVAL 50                                          //define the time interal(in milisecond) between each samples
+#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
 
 //The curves
-static float LPGCurve[]   = {2.3f,0.21f,-0.47f};
+static float LPGCurve[]   = {2.3f,0.21f,-0.47f};                                
 static float COCurve[]    = {2.3f,0.72f,-0.34f};
 static float SmokeCurve[] = {2.3f,0.53f,-0.44f};