Servo motor using wiring Pi problems

Question

I am looking for solution for something wrong happen in my programme i have configuration for control RC motor over RasPi using Wiring Pi here is code

#include<stdio.h>
#include<netinet/in.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netdb.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>

// header files for wiring to servo WIringPi
#include <wiringPi.h>
#include <softPwm.h>

#define PIN 0

//main programme that inittiate all socket for server
int main()
{
int i;
        //declaration for Wiring COnfiguration
        if(wiringPiSetup()==-1)
        {
                printf("Setup to servo fail");
                exit(0);
        }
        else
        {
                printf("Servo setup Done \n");
        }

        pinMode(0,OUTPUT);
        digitalWrite(0,LOW);

        printf("started \n");
        softPwmCreate(0,0,200);

 for (;;)
{
        printf("start a loop");
        for (i = 0 ; i <=180  ; ++i)
        {
                softPwmWrite (PIN, i) ;
                printf("\n Loop : %d ",i );
                delay (100) ;
        }
        delay (300) ;

        for (i = 180 ; i >= 0 ; --i)
        {
                softPwmWrite (PIN, i) ;
                printf("\n Loop : %d",i);       
                delay (100) ;
        }
delay (10) ;
}
}

i dont know what is wrong with this code

When It takes angle as 5 it start moving and moves total 180 degree when input integer i = 25

so its like

i=5 then 0 degree and i=25 then 180 degree

If anyone can help what is wrong?

Answer 1

I have run the program whilst monitoring the pulses with my piscope.

When softPwmWrite is called with a parameter i then pulses of 100*i µs are generated.

This means your servo is responding to pulses in the range 500 µs (i=5) to 2500 µs (i=25).

Sending pulses outside that range will be damaging the servo (some servos will strip their gears).

I suggest you constrain the calls to softPwmWrite to be between 5 and 25.