chi mi spiega questo codice please

Stavo cercando di capire come funziona la libreria del BRACCIO ROBOTICO della TINKERKIT (partner di arduino).
Perchè voglio capire come funziona il sotfstar, ma non l'ho capita mi date una mano please!!

if(soft_start_level!=SOFT_START_DISABLED)
    		_softStart(soft_start_level);
	return 1;
}

/*
Software implementation of the PWM for the SOFT_START_CONTROL_PIN,HIGH
@param high_time: the time in the logic level high
@param low_time: the time in the logic level low
*/
void _Braccio::_softwarePWM(int high_time, int low_time){
	digitalWrite(SOFT_START_CONTROL_PIN,HIGH);
	delayMicroseconds(high_time);
	digitalWrite(SOFT_START_CONTROL_PIN,LOW);
	delayMicroseconds(low_time); 
}

/*
* This function, used only with the Braccio Shield V4 and greater,
* turn ON the Braccio softly and save it from brokes.
* The SOFT_START_CONTROL_PIN is used as a software PWM
* @param soft_start_level: the minimum value is -70, default value is 0 (SOFT_START_DEFAULT)
*/
void _Braccio::_softStart(int soft_start_level){      
	long int tmp=millis();
	while(millis()-tmp < LOW_LIMIT_TIMEOUT)
		_softwarePWM(80+soft_start_level, 450 - soft_start_level);   //the sum should be 530usec	

	while(millis()-tmp < HIGH_LIMIT_TIMEOUT)
		_softwarePWM(75 + soft_start_level, 430 - soft_start_level); //the sum should be 505usec

	digitalWrite(SOFT_START_CONTROL_PIN,HIGH);
}