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:
0:67dd4036010a
Child:
1:7d669a801bb0
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SERVOGEN.h	Fri Sep 26 19:22:18 2014 +0000
@@ -0,0 +1,32 @@
+// Uses attach_us to generate servo pulse on single output pin
+// J. Bradshaw 20140925
+#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)
+  
+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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