Servo tries to rotate past stop on initialization

Using Arduino Motors, Mechanics, Power and CNC
1

Hey all. I am trying to create a library which cooridinates the control of sereral servos. I am having an issue where on initialization the servo goes to the stop, and then hums as if still trying to go beyond it. I know for a fact it is not a servo issue since I can upload other code I have written and they behave just fine. I am guessing it is in the way I am implementing the library, but after several hours of staring at it I am at a total loss. Here is the bare bones of my code:

Controller.h

#ifndef Controller_h
#define Controller_h

#include "Arduino.h"
#include "Servo.h"


class Controller
{
	private:
		int _rear_pin;
		Servo _rear_motor;
	public:
		Controller(int);
};
#endif

Controller.cpp

#include "Arduino.h"
#include "Servo.h"
#include "Controller.h"

Controller::Controller(int a){
	_rear_pin = a;
	
	_rear_motor.attach(_rear_pin);
	//delay(1);
}

Main Sketch

#include "Servo.h"
#include "Controller.h"

Controller go(9);

void setup(){}
void loop(){}

It is worth noting that if you uncomment the delay statement in .cpp the humming issue is resolved, with the remaining issue that no other commands (i.e. .write()) work. Any help or suggestions are appreciated.

2

You need to call write() immediately after to attach to define the correct starting position,
otherwise it defaults to something (which it sounds is the wrong thing).

You must not call delay() in a constructor, this will hang the system totally.

In fact never call anything in a constructor, just setup the variable values, and
write an init() method for initialization - constructors run before the Arduino is
correctly configured.

3

And that did it! :slight_smile:

Thanks a lot for the helpful answer. I figured I was overlooking something like that.