Diff: pwm_in.cpp

Revision:

13:41d102a53caf

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pwm_in.cpp	Sun Oct 30 02:06:03 2016 +0000
@@ -0,0 +1,56 @@
+#include "pwm_in.h"
+#include "mbed.h"
+
+float map(float x, float in_min, float in_max, float out_min, float out_max)
+{
+    return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
+}
+
+float constrain(float in, float min, float max)
+{
+    if(in > max) return max;
+    if(in < min) return min;
+    return in;
+}
+
+PWM_IN::PWM_IN(PinName pin, int usec_min, int usec_max)
+{
+    int_in = new InterruptIn(pin);
+    dig_in = new DigitalIn(pin);
+    int_in->rise(this, &PWM_IN::handle_rise);
+    int_in->fall(this, &PWM_IN::handle_fall);
+    this->usec_min = usec_min;
+    this->usec_max = usec_max;
+}
+
+
+bool PWM_IN::get_enabled()
+{
+    return enabled;
+}
+
+void PWM_IN::handle_rise()
+{
+    enabled = true;
+    timer.stop();
+    timer.reset();
+    timer.start();
+    was_on = true;
+}
+
+void PWM_IN::handle_fall()
+{
+    was_on = false;
+    usecs = timer.read_us();
+    timer.stop();
+    timer.reset();
+    timer.start();
+}
+
+float PWM_IN::get_throttle()
+{
+    if(timer.read_us() > 40000) enabled = false;
+    if(!enabled) return -1;
+    return constrain(map((float)usecs, usec_min, usec_max, 0, 1), 0, 1);
+}
+