Ramana R
This is a library for the MQ9 gas sensor module.
Diff: MQ9.cpp
- Revision:
- 0:7712450a546d
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/MQ9.cpp Tue May 01 20:26:00 2018 +0000
@@ -0,0 +1,35 @@
+#include "MQ9.h"
+
+MQ9::MQ9 (PinName const &p) : _pin(p)
+{
+ _LPG_ppm = 0.0;
+ _CO_ppm = 0.0;
+ _Methane_ppm = 0.0;
+}
+
+int MQ9::read()
+{
+ float sensorDat = _pin.read();
+ float sensorVolt = sensorDat * 3.3 / 4095;
+
+ _LPG_ppm = 26.572*exp(1.2894*sensorVolt);
+ _CO_ppm = 10.938*exp(1.7742*sensorVolt);
+ _Methane_ppm = 3.027*exp(1.0698*sensorVolt);
+
+ return MQ9_STATUS_PASS;
+}
+
+float MQ9::getLPG_ppm()
+{
+ return _LPG_ppm;
+}
+
+float MQ9::getCO_ppm()
+{
+ return _CO_ppm;
+}
+
+float MQ9::getMethane_ppm()
+{
+ return _Methane_ppm;
+}
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