jim hamblen
Demo of LED lighting effects using PWM and wait for time delays. Pins are setup for LPC1768 platform’s LEDs. For complete information, see http://developer.mbed.org/users/4180_1/notebook/led-lighting-effects-for-modelers/
Diff: main.cpp
- Revision:
- 0:a903b3cf5317
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Fri Nov 28 17:59:16 2014 +0000
@@ -0,0 +1,36 @@
+#include "mbed.h"
+//LED Railroad Crossing Lighting Effect
+PwmOut myled(LED1);
+PwmOut myled2(LED4);
+//Use a PWM output to enable dimming
+//1.0 is full on, 0.0 off, 0.5 50% on
+
+//function to simulate incandescent bulb warm up
+//and cool down cycles
+void incandescent_bulb(PwmOut led, float on_time = 0.1,
+float warm_time = 0.2)
+{
+ //LED warm up effect using PWM
+ for(int i=0; i<10; i++) {
+ led = i/10.0;
+ wait(warm_time/10.0);
+ }
+ //LED at full brightness level
+ led = 1.0;
+ wait(on_time);
+ //LED cool down effect using PWM
+ for(int i=9; i>0; i--) {
+ led = i/10.0;
+ wait(warm_time/10.0);
+ }
+ //LED off
+ led = 0.0;
+}
+
+int main()
+{
+ while(1) {
+ incandescent_bulb(myled);
+ incandescent_bulb(myled2);
+ }
+}