Joseph Bradshaw / ServoOut

Library for generating servo pulses from mbed output pins

Dependents:   mbed_ES20X_Tester MadPulseCntrl ES413Integration Emaxx_Navigation ... more

Fork of SERVOGEN by Joseph Bradshaw

ServoOut Library

Assign the ServoOut object (output pin) a value in microseconds to change the servo pulse. Note that the default range is between 900 and 2100 microseconds.

Library for generating servo pulses using the Ticker class

/media/uploads/jebradshaw/mbedwsesbc_servos.jpg

/media/uploads/jebradshaw/mbed_servo_pulses.jpg

include the mbed library with this snippet

// ServoOut Class test program
// J. Bradshaw 20140925
#include "mbed.h"
#include "ServoOut.h" 
 
ServoOut servo1(p21);
ServoOut servo2(p24);
DigitalOut led1(LED1);
 
int main() {
    servo1.pulse_us = 0;        
    // spin in a main loop. flipper will interrupt it to call flip
    while(1) {
        for(float cycle=0.0;cycle<2.0*3.14159;cycle+=.003){
            //small amplitude sine wave on servo1
            servo1 = 300 * sin(cycle) + 1500;            
            //ramp up the second servo2 channel relative to cycle
            servo2 = 1000 + cycle*159; // .001/(2*PI)
            
            wait(.001); //short delay
        }
        led1 = !led1;   //toggle led1 to indicate activity
    }//while(1)
}//main

Diff: ServoGen.h

Revision:
4:7043ab96dd4a
Parent:
3:edc18509ff11
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ServoGen.h	Thu Apr 09 20:49:29 2015 +0000
@@ -0,0 +1,89 @@
+// J. Bradshaw 20150409
+/** ServoGen Class for Generating servo pulses on single output pin
+ * Copyright (c) 2014, jbradshaw (http://mbed.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+*
+* Example:
+* @code
+*#include "mbed.h"
+*#include "ServoGen.h" 
+* 
+*ServoGen servo1(p21);
+*ServoGen servo2(p24);
+*DigitalOut led1(LED1);
+* 
+*int main() {
+*    servo1.pulse_us = 0;        
+*    // spin in a main loop. flipper will interrupt it to call flip
+*    while(1) {
+*        for(float cycle=0.0;cycle<2.0*3.14159;cycle+=.003){
+*            //small amplitude sine wave on servo1
+*            servo1.pulse_us = 300 * sin(cycle) + 1500;            
+*            //ramp up the second servo2 channel relative to cycle
+*            servo2.pulse_us = 1000 + cycle*159; // .001/(2*PI)
+*            
+*            wait(.001); //short delay
+*        }
+*        led1 = !led1;   //toggle led1 to indicate activity
+*    }//while(1)
+*}//main
+*
+*@endcode
+*/
+
+#ifndef MBED_SERVOGEN_H
+#define MBED_SERVOGEN_H
+ 
+#include "mbed.h"
+
+/**
+ * SERVOGEN Class.
+ */
+
+class ServoGen {
+public:
+    /**
+     * Constructor.
+     *
+     * @param pin - servo pulse output pin
+     */         
+     ServoGen(PinName pin);
+    
+    int pulse_us;       //determines the pulse width in microseconds (default is 0 = OFF)
+    int pulseMin;       //minimum pulse width (default is 900 microseconds)
+    int pulseMax;       //maximum pulse width (default is 2100 microseconds)
+    
+    void write(int pulse);  //
+    int read(void);
+    
+        /**  Shorthand for the write and read functions */
+    ServoGen& operator= (int pulse_us);
+    ServoGen& operator= (ServoGen& rhs);
+    operator int();
+  
+private:
+    void tickFunct(void);   //Function that takes care of the servo pulse generation
+    Ticker *ticker;         //pointer to ticker object
+    DigitalOut _pin;        //make assigned pin a digital output
+    int _sCycle;            //flag to toggle for keeping track of servo cycle
+};
+ 
+#endif
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