Alef Sin
A simple PWM decoder class. It is based on using 2 interrupts, one for rising and another for falling edges of the input pulse. This is a very simple approach, possibly accurate enough to decode RC receiver pulses.
Diff: pulse_decoder.cpp
- Revision:
- 0:b0ec6b86deaa
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/pulse_decoder.cpp Sun May 15 11:08:46 2016 +0000
@@ -0,0 +1,27 @@
+#include "mbed.h"
+#include "pulse_decoder.h"
+
+pulse_decoder::pulse_decoder(PinName pin)
+ : interrupt(pin), high_period(0), low_period(false)
+{
+ interrupt.rise(this, &pulse_decoder::rising_edge);
+ interrupt.fall(this, &pulse_decoder::falling_edge);
+}
+
+void pulse_decoder::rising_edge()
+{
+ high_timer.start();
+ low_timer.stop();
+
+ low_period = low_timer.read_us();
+ low_timer.reset();
+}
+
+void pulse_decoder::falling_edge()
+{
+ high_timer.stop();
+ low_timer.start();
+
+ high_period = high_timer.read_us();
+ high_timer.reset();
+}