Measure Distance

Dependencies:   mbed

Files at this revision

API Documentation at this revision

Comitter:
tadhgjones
Date:
Wed Dec 16 10:38:23 2020 +0000
Parent:
7:71da0dbf4400
Commit message:
EE3023

Changed in this revision

Speaker.h Show annotated file Show diff for this revision Revisions of this file
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 71da0dbf4400 -r f3ab61374cd0 Speaker.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Speaker.h	Wed Dec 16 10:38:23 2020 +0000
@@ -0,0 +1,52 @@
+class Speaker
+{
+public:
+    Speaker(PinName pin) : _pin(pin) {
+// _pin(pin) means pass pin to the Speaker Constructor
+// precompute 32 sample points on one sine wave cycle
+// used for continuous sine wave output later
+        for(int k=0; k<32; k++) {
+            Analog_out_data[k] = int (65536.0 * ((1.0 + sin((float(k)/32.0*6.28318530717959)))/2.0));
+            // scale the sine wave to 16-bits - as needed for AnalogOut write_u16 arg
+        }
+
+    }
+// class method to play a note based on AnalogOut class
+    void PlayNote(float frequency, float duration, float volume) {
+        // scale samples using current volume level arg
+        for(int k=0; k<32; k++) {
+            Analog_scaled_data[k] = Analog_out_data[k] * volume;
+        }
+        // reset to start of sample array
+        i=0;
+        // turn on timer interrupts to start sine wave output
+        Sample_Period.attach(this, &Speaker::Sample_timer_interrupt, 1.0/(frequency*32.0));
+        // play note for specified time
+        wait(duration);
+        // turns off timer interrupts
+        Sample_Period.detach();
+        // sets output to mid range - analog zero
+        this->_pin.write_u16(32768);
+
+    }
+private:
+// sets up specified pin for analog using AnalogOut class
+    AnalogOut _pin;
+    // set up a timer to be used for sample rate interrupts
+    Ticker Sample_Period;
+
+    //variables used by interrupt routine and PlayNote
+    volatile int i;
+    short unsigned Analog_out_data[32];
+    short unsigned Analog_scaled_data[32];
+
+// Interrupt routine
+// used to output next analog sample whenever a timer interrupt occurs
+    void Sample_timer_interrupt(void) {
+        // send next analog sample out to D to A
+        this->_pin.write_u16(Analog_scaled_data[i]);
+        // increment pointer and wrap around back to 0 at 32
+        i = (i+1) & 0x01F;
+    }
+};
+
diff -r 71da0dbf4400 -r f3ab61374cd0 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Dec 16 10:38:23 2020 +0000
@@ -0,0 +1,23 @@
+#include "mbed.h"
+#include "hcsr04.h"
+#include  "Speaker.h"
+
+HCSR04  usensor(p25,p6);
+Serial pc(USBTX, USBRX);
+Speaker mySpeaker(p18);
+
+unsigned int dist;
+int main()
+{
+ 
+    while(1) {
+        usensor.start();
+        wait_ms(50); 
+        dist=usensor.get_dist_cm();
+        
+        mySpeaker.PlayNote(329.63, 0.5, 1.0);
+        
+        pc.printf("cm:%ld\n",dist );
+ 
+    }
+}
\ No newline at end of file
diff -r 71da0dbf4400 -r f3ab61374cd0 mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Wed Dec 16 10:38:23 2020 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/078e4b97a13e