Diff: SlowPWM.cpp

Revision:

0:76861123625b

Child:

1:386d04fe1e37

diff -r 000000000000 -r 76861123625b SlowPWM.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SlowPWM.cpp	Tue Jun 18 10:52:51 2019 +0000
@@ -0,0 +1,59 @@
+#include "slowPWM.h"
+ 
+slowPWM::slowPWM(const PinName pin ):DigitalOut(pin)
+{
+    _repeatTime=1;
+    _timeOn=0.5f;
+}
+ 
+slowPWM::slowPWM( float period, float highTime, const PinName pin ):DigitalOut(pin)
+{
+    setPeriod(period);
+    setHighTime(highTime);
+    start();
+}
+ 
+void slowPWM::setPeriod(float period)
+{
+    _repeatTime = period;
+    if (_repeatTime <= 0)   // check it's not 0 or negative
+        _repeatTime = 1;
+    setHighTime(_timeOn);  // perform sanity check on high time
+}
+ 
+void slowPWM::setHighTime(float highTime)
+{
+    _timeOn = highTime;
+    if (_timeOn >= _repeatTime)  // check it's not more than the cycle time.
+        _timeOn = _repeatTime/2; // set to 50% if invalid 
+}
+ 
+void slowPWM::setDutyCycle(float cycle) {
+        if ((cycle >=0) && (cycle <=1)) {
+        _timeOn = _repeatTime*cycle; 
+        } else
+        _timeOn = _repeatTime/2; // set to 50% if invalid 
+}
+ 
+void slowPWM::stop()
+{
+    cycleTimer.detach();
+}
+ 
+// start things.
+void slowPWM::start()
+{
+    cycleTimer.attach(callback(this,&slowPWM::onCycleStart),_repeatTime);
+    onCycleStart();
+}
+ 
+void slowPWM::onTurnOff(void)
+{
+    write(0);
+}
+ 
+void slowPWM::onCycleStart(void)
+{
+    offTimer.attach(callback(this,&slowPWM::onTurnOff),_timeOn);
+    write(1);
+}