Diff: main.cpp

Revision:

0:68ad188ca8c4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Oct 21 12:31:41 2015 +0000
@@ -0,0 +1,41 @@
+/** 03_pwm_led
+ * This program controls the duty cycle of 
+ * a PWM output connected to LED1 (LED_RED)
+ * through the serial connection.
+ *
+ * Valid commands: '1', '5', '9'
+ * Corresponding duty cycle: 10%, 50%, 90% 
+ * Period: 2000 ms
+ *
+ * Hardware requirements:
+ *  - FRDM-KL25Z board
+ */ 
+
+#include "mbed.h"
+
+PwmOut myled(LED1);
+Serial pc(USBTX, USBRX); // tx, rx
+
+int main() {
+    myled.period_ms(20);    //Period = 20 ms
+    myled.write(1.0);       //Led off at start
+    pc.printf("\r\n03_pwm_led: this program controls the duty cycle of a \r\nPWM output connected to LED1 (LED_RED) through the serial connection.\r\n");
+    pc.printf("Period: 20 ms, Valid commands are: '1', '5', '9'\r\nThe corresponding duty cycle are: 1%, 50%, 99%\r\n");
+
+    while(1) {
+        char c = pc.getc(); //read next character
+        if(c=='1') {
+            myled = 0.99f;   //LED has negative logic!
+            pc.printf("Duty cycle = 0.01\r\n");
+        }
+        else if(c=='5') {
+            myled = 0.5f;
+            pc.printf("Duty cycle = 0.5\r\n");        
+        }
+        else if(c=='9') {
+            myled = 0.01f;   //LED has negative logic!
+            pc.printf("Duty cycle = 0.99\r\n");            
+        }        
+        wait(0.2);
+    }
+}