Diff: PeriodicSensor.h

Revision:

0:8d34cc2ff388

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PeriodicSensor.h	Sun Mar 16 01:48:59 2014 +0000
@@ -0,0 +1,75 @@
+/* PeriodicSensor.h
+ * Tested with mbed board: FRDM-KL46Z
+ * Author: Mark Gottscho
+ * mgottscho@ucla.edu
+ */
+
+#ifndef PERIODICSENSOR_H
+#define PERIODICSENSOR_H
+
+#include "mbed.h"
+
+/**
+ * Abstract class from which most sensor classes can be derived.
+ * This class implements interrupt-driven periodic sampling
+ */
+class PeriodicSensor {
+    public:
+        /**
+         * Constructs a PeriodicSensor object. Default minimum sampling period is set to 0.05 sec.
+         */
+        PeriodicSensor();
+        
+        /**
+         * Constructs a PeriodicSensor object with a custom minimum sampling period (must be positive).
+         */
+        PeriodicSensor(float min_sampling_period);
+         
+        /**
+         * Destroys the object
+         */
+        ~PeriodicSensor();
+        
+        /**
+         * @returns true if there is new data ready to be retrieved.
+         */
+        bool isDataReady();
+        
+        /**
+         * Control the background sampling of the device via interrupts. If disabled, the device can still be sampled using the getter methods directly.
+         * @param enable if true, enables background sampling with the given sample period.
+         * @param sample_period sampling period in seconds. Must be at least 0.005 sec unless enable is false, in which case it is don't care.
+         */
+        void enableBackgroundSampling(bool enable, float sample_period);
+        
+        /**
+         * @returns true if background sampling is enabled.
+         */
+        bool isBackgroundSamplingEnabled();
+        
+        /**
+         * @returns the sample period in seconds, if background sampling is enabled. Else, non-positive return.
+         */
+        float getSamplePeriod();
+        
+        /**
+         * @returns the minimum sample period in seconds
+         */
+        float getMinSamplePeriod();
+        
+    protected:
+        volatile bool __dataReady;
+        
+    private:
+        /**
+         * This is the interrupt service routine that is called periodically when enabled.
+         */
+        virtual void __sample_data_ISR() = 0;
+        
+        Ticker __interrupt;
+        float __sample_period;
+        bool __background_sampling;
+        float __min_sample_period;
+};
+
+#endif
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