Diff: main.cpp

Revision:

0:a35b696aeb52

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Aug 14 13:54:28 2021 +0000
@@ -0,0 +1,44 @@
+#include "mbed.h"
+#include "hcsr04.h"
+
+Serial pc(PA_2, PA_15, 115200);
+
+HCSR04  usensor(PA_8,PA_11);
+AnalogOut Distance_out(A3);
+
+unsigned int dist;
+unsigned int time_us;
+float dist_mm;
+float dist_ratio;
+float dist_ratio_last;
+float dist_ratio_fil;
+const float height_max = 300; //unit: mm
+const float height_min = 50; //unit: mm
+
+int main()
+{
+    while(1) {
+        usensor.start();
+        dist=usensor.get_dist_cm();
+        time_us=usensor.get_pulse_us();
+        dist_mm = 346.0f*time_us/2000.0f;
+        
+//        pc.printf("cm:%d\n",dist );
+//        pc.printf("us:%d\n",time_us );
+        pc.printf("%.3f\n\r",dist_mm );
+
+        dist_ratio = (dist_mm - height_min)/(height_max - height_min);
+        if (dist_ratio > 2.0f) {dist_ratio = dist_ratio_last;}
+        dist_ratio_fil = (1.0f-0.03f)*dist_ratio_fil + 0.03f*dist_ratio;
+        
+        if (dist_ratio < 1.0f && dist_ratio > 0.0f) {
+            Distance_out = dist_ratio;
+        } else if (dist_ratio > 1.0f) {
+            Distance_out = 1.0f;
+        } else {
+            Distance_out = 0.0f;
+        }
+        dist_ratio_last = dist_ratio;
+//        pc.printf("%3.3f,%3.3f\n\r", dist_ratio, dist_ratio_fil );
+    }
+}
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