ece 4180 lab 3

Dependencies:   mbed wave_player mbed-rtos 4DGL-uLCD-SE SDFileSystem X_NUCLEO_53L0A1 HC_SR04_Ultrasonic_Library

Revision:
2:4845e2dae429
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/part2.h	Wed Feb 19 18:48:09 2020 +0000
@@ -0,0 +1,71 @@
+#include "mbed.h"
+#include "ultrasonic.h"
+ 
+Serial pc(USBTX, USBRX);
+
+void dist(int distance)
+{
+    //put code here to execute when the distance has changed
+    pc.printf("Distance %d mm\r\n", distance);
+}
+ 
+ultrasonic mu(p6, p7, .1, 1, &dist);    //Set the trigger pin to p6 and the echo pin to p7
+                                        //have updates every .1 seconds and a timeout after 1
+                                        //second, and call dist when the distance changes
+ 
+int run_part2()
+{
+    mu.startUpdates();//start measuring the distance
+    while(1)
+    {
+        //Do something else here
+        mu.checkDistance();     //call checkDistance() as much as possible, as this is where
+                                //the class checks if dist needs to be called.
+    }
+}
+
+//Theremin style demo using HC-SR04 Sonar and a speaker
+// moving a hand away/towards sonar changes audio frequency
+ 
+DigitalOut audio(p26); //output to speaker amp or audio jack
+DigitalOut led(LED1); 
+DigitalOut led2(LED2);
+ 
+Timeout cycle;
+ 
+volatile int half_cycle_time = 1;
+ 
+//two calls to this interrupt routine generates a square wave
+void toggle_interrupt()
+{
+    if (half_cycle_time>22000) audio=0; //mute if nothing in range
+    else audio = !audio; //toggle to make half a square wave
+    led = !led;
+    cycle.detach();
+    //update time for interrupt activation -change frequency of square wave
+    cycle.attach_us(&toggle_interrupt, half_cycle_time);
+}
+void newdist(int distance)
+{
+    //update frequency based on new sonar data
+    led2 = !led2;
+    half_cycle_time = distance<<3;
+}
+//HC-SR04 Sonar module
+ultrasonic mu2(p6, p7, .07, 1, &newdist);    
+//Set the trigger pin to p6 and the echo pin to p7
+//have updates every .07 seconds and a timeout after 1
+//second, and call newdist when the distance changes
+int run_part2_EC()
+{
+    audio = 0;
+    led = 0;
+    cycle.attach(&toggle_interrupt, half_cycle_time);
+    mu2.startUpdates();//start measuring the distance with the sonar
+    while(1) {
+        //Do something else here
+        mu2.checkDistance();     
+        //call checkDistance() as much as possible, as this is where
+        //the class checks if dist needs to be called.
+    }
+}
\ No newline at end of file