This program uses SeeedArch to control the two servo motors of a small sailboat. One is general servo (rudder), and the other one is the multi-turn servo.

Dependencies:   Servo mbed

Revision:
0:6049dd45a7aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Nov 20 00:50:55 2013 +0000
@@ -0,0 +1,122 @@
+#include "mbed.h"
+#include "Servo.h"
+
+//DigitalOut led1(LED1);
+//DigitalOut led2(LED2);
+//DigitalOut led3(LED3);
+//DigitalOut led4(LED4);
+
+/*
+The arch cookbook in mbed.org website
+    http://mbed.org/users/viswesr/notebook/arch-cookbook/
+*/
+PwmOut servo(P1_24);    //seeedarch pin for the multiturn servo
+Servo rudder(P1_25);    //seeedarch pin for the rudder servo
+
+Serial bbb(P1_18,P1_17);//seeedarch pin for the UART communication tx, rx
+
+
+AnalogIn ain(P0_11);//seeedarch analog in pin
+
+void servo_initial(void);
+void multiturn_servo(int type, int circle);
+
+int main() 
+{
+    int circle=5;
+    
+    //servo_initial();
+    bbb.baud(115200);
+    while(~bbb.writeable());
+    bbb.putc('s');
+    while(1)
+    {
+         if(bbb.readable()) {
+            bbb.putc(bbb.getc()+1);
+        }    
+
+    }
+  
+    while(1)
+    {
+        //Multiturn servo
+        multiturn_servo(2,1);//20+10 degree
+        multiturn_servo(0,10);
+        multiturn_servo(2,1);//20+20 degree
+        multiturn_servo(0,10);
+        multiturn_servo(2,1);//50
+        multiturn_servo(0,10);
+        multiturn_servo(2,1);//60
+        multiturn_servo(0,10);
+        multiturn_servo(2,1);//70
+        multiturn_servo(0,10);
+        multiturn_servo(2,1);//80
+        multiturn_servo(0,10); 
+        
+        
+        //multiturn_servo(1,1);
+        multiturn_servo(1,2);
+        multiturn_servo(0,10);
+        multiturn_servo(1,2);
+        multiturn_servo(0,10);
+        multiturn_servo(1,2);
+        multiturn_servo(0,10);
+        multiturn_servo(1,2);
+        multiturn_servo(0,10);
+        multiturn_servo(1,4);
+        multiturn_servo(0,10);
+        multiturn_servo(1,5);
+        multiturn_servo(0,10);
+        wait(2);
+        
+        //Rudder servo
+        rudder.write(0.0);
+        wait(0.01);
+        wait(2);
+        rudder.write(0.5);
+        wait(0.01);
+        wait(2);
+        rudder.write(1.0);
+        wait(0.01);
+        wait(2);
+     }      
+}
+
+void servo_initial()
+{
+        servo.period_ms(22);          //multiturn servo requires a 22ms period
+        //Initial the position to far end
+        multiturn_servo(1,10);
+        multiturn_servo(0,20);
+}
+
+/*
+    Control the multiturn servo to turn or stop it
+    To turn the servo clockwise use pulsewidth 1.7 ms
+    To turn the servo counter clockwise use pulsewidth 2.0 ms
+    To stop the servo use the pulsewidth 10 ms
+*/
+void multiturn_servo(int type, int circle)
+{
+    float pulse_width=0.0;
+    int i;
+    
+    switch(type)
+    {
+        case 0:
+            pulse_width=10.0;//stop
+            break;
+        case 1:
+            pulse_width=1.6;//counter clockwise
+            break;
+        case 2:
+            pulse_width=2.0;//clockwise
+            break;
+    }
+    for(i=0;i<circle;i++)
+    {
+        servo.pulsewidth_ms(pulse_width); // servo position determined by a pulsewidth between 1-2ms
+        wait(0.25);
+    }   
+
+}
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