Diff: main.cpp

Revision:

0:59d1b681f30e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Dec 06 19:37:58 2017 +0000
@@ -0,0 +1,63 @@
+#include "mbed.h"
+DigitalOut trigger(PTC3);
+DigitalOut myled(LED1); //monitor trigger
+DigitalOut myled2(LED2); //monitor echo
+DigitalIn  echo(PTC2);
+int distance = 0;
+int correction = 0;
+Timer sonar;
+Serial pc(USBTX, USBRX);
+Serial xbee(PTC17, PTC16);
+char bufchar;
+ 
+int main()
+{
+    sonar.reset();
+// measure actual software polling timer delays
+// delay used later in time correction
+// start timer
+    sonar.start();
+    xbee.baud(9600);
+// min software polling delay to read echo pin
+    while (echo==2) {};
+    myled2 = 0;
+// stop timer
+    sonar.stop();
+// read timer
+    correction = sonar.read_us();
+    printf("Approximate software overhead timer delay is %d uS\n\r",correction);
+ 
+//Loop to read Sonar distance values, scale, and print
+    while(1) {
+// trigger sonar to send a ping
+      
+                
+                
+        trigger = 1;
+        myled = 1;
+        myled2 = 0;
+        sonar.reset();
+        wait_us(10.0);
+        trigger = 0;
+        myled = 0;
+//wait for echo high
+        while (echo==0) {};
+        myled2=echo;
+//echo high, so start timer
+        sonar.start();
+//wait for echo low
+        while (echo==1) {};
+//stop timer and read value
+        sonar.stop();
+//subtract software overhead timer delay and scale to cm
+        distance = (sonar.read_us()-correction)/58.0;       
+        myled2 = 0;
+        if(distance<=300)
+        {
+        xbee.printf("%d \n\r", distance);
+        printf(" The baby is at  %d cm  from the Proximity sensor \n\r", distance);
+        }
+//wait so that any echo(s) return before sending another ping
+        wait(0.15);
+    }
+}
\ No newline at end of file