Richard Kuo
mbed PWM output to play siren
Revision 0:ed48c1d4c02f, committed 2016-10-21
- Comitter:
- rkuo2000
- Date:
- Fri Oct 21 07:35:16 2016 +0000
- Commit message:
- mbed PWM siren
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/.gitignore Fri Oct 21 07:35:16 2016 +0000 @@ -0,0 +1,4 @@ +.build +.mbed +projectfiles +*.py*
--- /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);
+ }
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed-os.lib Fri Oct 21 07:35:16 2016 +0000 @@ -0,0 +1,1 @@ +https://github.com/ARMmbed/mbed-os/#a6f3fd1a60d5df59246d7caf3f108c4d34e1808e