Diff: Distance_HC_SR04.h

Branch:

CLASS_IMPLEMENTATION

Revision:

5:1a69f40177b0

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Distance_HC_SR04.h	Mon Dec 21 20:54:09 2015 +0000
@@ -0,0 +1,54 @@
+#ifndef MBED_DISTANCE_HC_SR04_H
+#define MBED_DISTANCE_HC_SR04_H
+ 
+#include "mbed.h"
+ 
+#define TIMEOUT_DELAY_US    (25000)
+#define CALC_COEFF          (340.0f/(2.0f*1000.0f))
+#define TICKS_RANGE_MAX     (15000)
+#define TICKS_RANGE_MIN     (150)
+#define TRIG_PULSE_US       (50)
+
+typedef enum { IDLE, STARTED, COMPLETED, TIMEOUT, OUT_OF_RANGE_MIN, OUT_OF_RANGE_MAX, ERROR_SIG } Distance_HC_SR04_state;
+
+/** Distance_HC_SR04 class.
+ *
+ *  Library for interfacing ultrasonic distance measurement device HC-SR04.
+ *  Functionality includes detection of error in echo signal, detection of timeout and limits of reliable measurement.
+ *
+ */
+class Distance_HC_SR04 {
+
+public:
+    Distance_HC_SR04(PinName trig, PinName echo, uint32_t tout_us = TIMEOUT_DELAY_US, float coeff = CALC_COEFF,
+            uint32_t tmin_us = TICKS_RANGE_MIN, uint32_t tmax_us = TICKS_RANGE_MAX);
+    void trigger(void);
+    Distance_HC_SR04_state getState(void);
+    void reset(void);
+    uint32_t getTicks(void);
+    float getDistance(void);
+    float getCoeff(void);
+    void setCoeff(float coeff);
+    float measureDistance(void);
+    uint32_t measureTicks(void);
+
+    void _tout(void);
+    void _rising(void);
+    void _falling(void);
+
+private:
+    DigitalOut  _trig;
+    InterruptIn _echo;
+    uint32_t    _tout_us;
+    float       _coeff;
+    uint32_t    _tmin_us;
+    uint32_t    _tmax_us;
+
+    Timer       _timer;
+    Timeout     _timeout;
+
+    volatile Distance_HC_SR04_state _state;
+    uint32_t                        _ticks_us;
+};
+ 
+#endif
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