Diff: hcsr04.cpp

Revision:

0:568f3374c9a7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hcsr04.cpp	Tue Mar 26 12:54:18 2019 +0000
@@ -0,0 +1,117 @@
+/* Copyright (c) 2013 Prabhu Desai
+ * pdtechworld@gmail.com
+ *
+ * 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.
+ */
+
+
+#include "hcsr04.h"
+
+HCSR04::HCSR04(PinName TrigPin,PinName EchoPin):
+    trigger(TrigPin), echo(EchoPin)
+{
+    pulsetime.stop();
+    pulsetime.reset();
+    echo.rise(this,&HCSR04::isr_rise);
+    echo.fall(this,&HCSR04::isr_fall);
+    trigger=0;
+}
+
+HCSR04::~HCSR04()
+{
+}
+
+void HCSR04::isr_rise(void)
+{
+    pulsetime.start();
+}
+void HCSR04::start(void)
+{
+    trigger=1;
+    wait_us(10);
+    trigger=0;
+}
+
+void HCSR04::isr_fall(void)
+{
+    pulsetime.stop();
+    pulsedur = pulsetime.read_us();
+    distance= (pulsedur*343)/20000;
+    pulsetime.reset();
+}
+
+void HCSR04::rise (void (*fptr)(void))
+{
+    echo.rise(fptr);
+}
+void HCSR04::fall (void (*fptr)(void))
+{
+    echo.fall(fptr);
+}
+
+unsigned int HCSR04::get_dist_cm()
+{
+    return distance;
+}
+unsigned int HCSR04::get_pulse_us()
+{
+    return pulsedur;
+}
+
+float HCSR04::filter(int* measure, int n) {
+	int temp;
+	for(int i=0; i<n-1; i++) {
+		for(int k=0; k<n-1-i; k++) {
+			if(measure[k] > measure[k+1]) {
+				temp = measure[k];
+				measure[k] = measure[k+1];
+				measure[k+1] = temp;
+	        }
+	     }
+	 }
+	if(n%2==0) {
+	    int pos_1 = (int)n/2.0 + .5;
+	    int pos_2 = (int)n/2.0 - .5;
+		value = (measure[pos_1]+measure[pos_2])/2;
+	} else {
+		value = measure[n/2];
+	}
+
+	return value;
+}
+
+/*******************************************************
+   Here is a sample code usage
+********************************************************* 
+#include "hcsr04.h"
+HCSR04  usensor(p25,p6);
+int main()
+{
+    unsigned char count=0;
+    while(1) {
+        usensor.start();
+        wait_ms(500); 
+        dist=usensor.get_dist_cm();
+        lcd.cls();
+        lcd.locate(0,0);
+        lcd.printf("cm:%ld",dist );
+ 
+        count++;
+        lcd.locate(0,1);
+        lcd.printf("Distance =%d",count);
+        
+    }
+*/