CO2 Sensor MH-Z19 Class (uses interrupt input as PWM input)

Dependencies:   mbed

Revision:
0:3c154d34f47e
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MH_Z19.h	Thu Aug 11 00:41:23 2016 +0000
@@ -0,0 +1,50 @@
+/* mbed MH-Z19 Library
+ * Copyright (c) 2016, zeus3110
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MH_Z19_H
+#define MH_Z19_H
+
+#include "mbed.h"
+
+#define PWM_CYCLE_MS 1004
+#define CO2_MAX_PPM 5000
+
+class MH_Z19 {
+public:
+    /** Create a MH_Z19
+     *
+     * @param Port The pwm input pin (must support InterruptIn)
+     */ 
+    MH_Z19(PinName Port);
+
+    int ReadCO2PPM();
+
+protected:        
+    void rise();
+    void fall();
+    
+    InterruptIn Port;
+    Timer T;
+    int OnWidth;
+};
+
+#endif