Diff: HCSR04.h

Revision:

0:a3bc6812cccb

Child:

1:6f9e41e319ad

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HCSR04.h	Wed Jun 03 16:56:09 2020 +0000
@@ -0,0 +1,83 @@
+//-------------------------------------
+// Short Example how to use this class:
+//-------------------------------------
+/*
+#include "mbed.h"
+#include "HCSR04.h"
+
+Serial pc(USBTX, USBRX, 115200);
+HCSR04 sensor(D9, D8);
+
+int main(void)
+{    
+    pc.printf("\nHCSR04 - Interrupt\n");
+    sensor.startSensor(2);
+    while(1)
+    {
+        if(sensor.checkUpdate())
+        {
+            pc.printf("Distance: %.2f \n", sensor.getDistance());
+        }
+    }
+    return 0;
+}
+*/
+#ifndef HCSR04_H
+#define HCSR04_H
+
+#include "mbed.h"
+
+
+class HCSR04
+{
+private:
+    // Trigger PIN - to write LOW and HIGH
+    DigitalOut trigger;
+    // ECHO PIN - to start Function after rising/falling flank
+    InterruptIn echo;
+    // Ticker object to periodicly start the measurement
+    Ticker execute;
+    // Timeout to write LOW to Trigger pin after 10 microseconds
+    Timeout go_low;
+    // Timer to measure the time between the sonic burst goes out and in again
+    Timer get_time;
+    // Variables for the update status and the the distance in microseconds 
+    volatile float distance_us;
+    volatile bool update;
+    
+    // Called by TICKER object to periodicly write HIGH to TRIGGER PIN
+    void sendHigh(void);
+    // Called by TIMEOUT Object to set TRIPPER PIN LOW again
+    void sendLow(void);
+    // Called by interrupt - rising flank on ECHO PIN
+    void startTimer(void);
+    // Called by interrupt - falling flank on ECHO PIN
+    void stopTimer(void);
+
+public:
+    // Constructor
+    HCSR04(PinName _trigger, PinName _echo):trigger(_trigger), echo(_echo)
+    {
+        // Attach member functions to InterruptIn for changing state on ECHO PIN [HIGH,LOW]
+        echo.rise(callback(this, &HCSR04::startTimer));
+        echo.fall(callback(this, &HCSR04::stopTimer));
+        
+        // Default Values
+        trigger.write(0);
+        update = false;
+        
+    }
+    
+    // Function to return the distance, should be called if "checkUpdate()" returns true
+    float getDistance(void);
+    // Check for an updatet status for the measurement
+    bool checkUpdate(void);
+    // Function to start sending HIGH in periodic intervalls to TRIGGER PIN via a TICKER Object
+    void startSensor(int freq);
+    // Function to stop sending HIGH to TRIGGER PIN
+    void stopSensor(void);
+    
+
+};
+
+#endif
\ No newline at end of file