Diff: main.cpp

Revision:

0:ed48c1d4c02f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Oct 21 07:35:16 2016 +0000
@@ -0,0 +1,60 @@
+//NuMaker-PFM-NUC472 PWM0 output Siren to a speaker
+#include "mbed.h"
+
+#define Ambulance_Siren_Low   650
+#define Ambulance_Siren_High  900
+#define Ambulance_Siren_L_period 400 // 0.4 sec
+#define Ambulance_Siren_H_period 600 // 0.6 sec
+
+#define PoliceCar_Siren_Low   650
+#define PoliceCar_Siren_High 1450
+#define PoliceCar_Siren_L_duration 230 // 0.23 sec
+#define PoliceCar_Siren_H_duration 100 // 0.1  sec
+
+PwmOut pwm0(PF_9); // PWM0 pin 
+
+void Ambulance_Siren(uint32_t siren_no)
+{
+    int i;
+    for (i=0; i<siren_no; i++) {
+        pwm0.period_us(1000000/Ambulance_Siren_Low);
+        pwm0.pulsewidth_us(1000000/Ambulance_Siren_Low/2); // set duty cycle to 50%        
+        Thread::wait(Ambulance_Siren_L_period);
+        pwm0.period_us(1000000/Ambulance_Siren_High);
+        pwm0.pulsewidth_us(1000000/Ambulance_Siren_High/2); // set duty cycle to 50% 
+        Thread::wait(Ambulance_Siren_H_period);
+    }
+    pwm0.pulsewidth_us(0);
+}
+
+void PoliceCar_Siren(uint32_t siren_no)
+{
+    int i, j;
+    int siren_freq;
+    
+    for (i=0; i<siren_no; i++) {
+        siren_freq = PoliceCar_Siren_Low;
+        for (j=0; j<(PoliceCar_Siren_L_duration); j++) {
+            pwm0.period_us(1000000/siren_freq);
+            pwm0.pulsewidth_us(1000000/siren_freq/2); // set duty cycle to 50%
+            Thread::wait(1);
+            siren_freq = siren_freq + (PoliceCar_Siren_High - PoliceCar_Siren_Low)/230; 
+        }       
+        siren_freq = PoliceCar_Siren_High;
+        for (j=0; j<PoliceCar_Siren_L_duration; j++) {
+            pwm0.period_us(1000000/siren_freq);
+            pwm0.pulsewidth_us(1000000/siren_freq/2); // set duty cycle to 50%
+            Thread::wait(1);
+            siren_freq = siren_freq - (PoliceCar_Siren_High - PoliceCar_Siren_Low)/100; 
+        }           
+    }
+    pwm0.pulsewidth_us(0);
+}
+
+int main()
+{
+      while(1) {
+        Ambulance_Siren(5);   
+        PoliceCar_Siren(5);
+        }
+}