Reddit servo + motor driver v1.0

/*
   April 3, 2019
   Reddit motor + servo driver
   Board = Uno

   This sketch sets a DC motor to spin at a single speed, and moves a servo back and forth between two settings.
   The DC motor speed is assumed to be set by PWM also.

*/

int dc_motor_pin = 3; // The PWM input to the DC motor controller is connected here.

int dc_motor_speed = 128; // This is the speed setting for the DC motor, that can range from zero to 255.
// This assumes that you are using a DC motor controller that allows setting the motor speed with a PWM value.

int servo_pin = 5; // The servo control pin is connected here.

int servo_interval_time = 100; // This is the time interval that the servo will change at, in milliseconds.
int servo_change_value = 5; // This is the amount that the servo will change, at each change interval.

int servo_current_value = 32; // This is the starting point for the servo. It must be a number between the minimum and maximum value.

int servo_minimum_value = 32; // This is the low end of where you want the servo to stop at. Zero is the lowest value you can put here.
int servo_maximum_value = 200; // This is the high end of where you want the servo to stop at. 255 is the highest value you can put here.

int servo_direction = 1; // This variable will flip back and forth between 1 and -1.
// Setting it to 1 will make the servo begin by turning upwards, and setting it to -1 will make the servo begin by turning downwards.



void setup() {
  analogWrite(dc_motor_pin, dc_motor_speed); // This sets the DC motor on at a fixed speed.
}



void loop() {
  change_servo_value(servo_change_value, servo_direction);
  check_current_servo_value();
  analogWrite(servo_pin, servo_current_value);
  delay(servo_interval_time);
}


void change_servo_value(int changeValue, int servoDirection) {
  // This changes the servo value up or down, depending on if servoDirection is 1 or -1.
  servo_current_value = servo_current_value + (changeValue * servoDirection);
}


void check_current_servo_value() {
  // This prevents the servo from turning past the minimum and maximum values,
  // and changes the direction when it hits either of the end values.
  if (servo_current_value < servo_minimum_value) {
    servo_current_value = servo_minimum_value;
    flip_servo_direction();
  }
  if (servo_current_value > servo_maximum_value) {
    servo_current_value = servo_maximum_value;
    flip_servo_direction();
  }
}

void flip_servo_direction() {
  // Because the direction control value is 1 or -1, you can change it to the "other" value just by multiplying it by -1.
  servo_direction = servo_direction * -1;
}