Revision 6:cf65fc8b0de1, committed 2018-06-05

Comitter:

haarkon

Date:

Tue Jun 05 07:25:09 2018 +0000

Parent:

5:9b1e318db5f1

Child:

7:014d36c33b73

Commit message:

Soft RC Servo (without PWMOut)

Changed in this revision

--- a/RC_Servo.cpp	Thu May 31 17:26:54 2018 +0000
+++ b/RC_Servo.cpp	Tue Jun 05 07:25:09 2018 +0000
@@ -1,21 +1,40 @@
 #include "RC_Servo.h"
 
-RC_Servo::RC_Servo(PinName PWM, int _extended) : _pwm(PWM)
+RC_Servo::RC_Servo(PinName PWM, int _extended) : _RCpwm(PWM)
 {
-    _pwm.period(0.02);
+    _tickRC.attach(callback(this,&RC_Servo::generatePwm),0.02);
     if (_extended) {
-        _pMin = 400;
-        _pMax = 2400;
+        _RCpMin = 400;
+        _RCpMax = 2400;
     } else {
-        _pMin = 1000;
-        _pMax = 2000;
+        _RCpMin = 1000;
+        _RCpMax = 2000;
     }
 }
 
-int RC_Servo::setLimits (int Tmin, int Tmax) {
-    if ((Tmin > 400) && (Tmin < Tmax))  _pMin = Tmin;
+void RC_Servo::generatePwm (void)
+{
+
+    static int  output = 0;
+    static long pulseWidthTime = 0;
+
+    if (pulseWidthTime == 0) pulseWidthTime = _RCpMin;
+    _tickRC.detach();
+    output = !output;
+    _RCpwm = output;
+
+    if (output == 1)    _tickRC.attach (callback(this,&RC_Servo::generatePwm), pulseWidthTime);
+    else {
+        _tickRC.attach (callback(this,&RC_Servo::generatePwm), 20000-pulseWidthTime);
+        pulseWidthTime = RCdelay;
+    }
+}
+
+int RC_Servo::setLimits (int Tmin, int Tmax)
+{
+    if ((Tmin > 400) && (Tmin < Tmax))  _RCpMin = Tmin;
     else return Tmin;
-    if ((Tmax < 2400) && (Tmin < Tmax)) _pMax = Tmax;
+    if ((Tmax < 2400) && (Tmin < Tmax)) _RCpMax = Tmax;
     else return Tmax;
     return 0;
 }
@@ -23,7 +42,7 @@
 void RC_Servo::write (float position)
 {
     if ((position >= 0) && (position <= 1))
-        _pwm.pulsewidth_us (_pMin + (int)(position * (_pMax - _pMin)));
+        RCdelay = _RCpMin + (long)((_RCpMax - _RCpMin) * position);
 }
 
 RC_Servo& RC_Servo::operator= (float position)

--- a/RC_Servo.h	Thu May 31 17:26:54 2018 +0000
+++ b/RC_Servo.h	Tue Jun 05 07:25:09 2018 +0000
@@ -51,6 +51,11 @@
 public :
 
     /**
+     * Global Variable that define pulsewidth in microsecond
+     */
+    long RCdelay; 
+
+    /**
      * Constructor of a RC Servo (analog).
      *
      * @param PWM (PinName) : is the Mbed pin used to generate the PWM signal
@@ -80,10 +85,13 @@
     RC_Servo& operator= (float position);
 
 private :
-    int _pMin, _pMax;
+    int         _RCpMin, _RCpMax;
+    Ticker      _tickRC;
+    
+    void generatePwm (void);
 
 protected :
-    PwmOut    _pwm ;
+    DigitalOut  _RCpwm ;
 
 };
 #endif //GP2A_H
\ No newline at end of file