Ultrasonic sensor used HC-SR04

Dependencies:   mbed

Files at this revision

API Documentation at this revision

Comitter:
tknara
Date:
Sun Jan 18 13:42:41 2015 +0000
Commit message:
Ultrasonic sensor

Changed in this revision

main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
diff -r 000000000000 -r 6947b0547f9f main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Jan 18 13:42:41 2015 +0000
@@ -0,0 +1,34 @@
+#include "mbed.h"
+
+Serial pc(USBTX,USBRX);
+DigitalOut trig(p21);
+DigitalOut testled(LED1);
+DigitalIn echo(p22);
+Timer t;
+#define sonic_spead 343.595*100;// cm
+
+int main() {
+    double time;
+    while(1) {
+        testled = 0;
+        t.reset();
+        trig = 1;
+        time = 0;
+        wait_us(10);
+        trig = 0;
+        if (echo == 1) {
+            t.start();
+            while(1){
+                if(echo == 0) {
+                    testled = 1;
+                    t.stop();
+                    time = t.read();
+                    time = time / 2.0 *sonic_spead;
+                    pc.printf("%lfcm\n\r",time);
+                    t.reset();
+                    break;
+                }
+            }
+        }
+    }
+}
diff -r 000000000000 -r 6947b0547f9f mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Sun Jan 18 13:42:41 2015 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/4fc01daae5a5
\ No newline at end of file