#include <math.h>
#define PWM 11      //PB3
#define left 9      //PB1
#define right 10     //PB2
#define minPWM 90   //minimal Duty-Cycle
#define maxPWM 180  //maximal Duty-Cycle
bool direction = true;
int counter = 0;
void setup() {
  // put your setup code here, to run once:
  pinMode(PWM , OUTPUT);
  digitalWrite(PWM,0);
  pinMode(left, OUTPUT);
  pinMode(right, OUTPUT);
  setDir(direction);
  TCCR2A = 0b10100011;
  TCCR2B = 0b00000010;
  OCR2A = 0;
  Serial.begin(9600);
  Serial.println("--- Beginn ---");
  OCR2A = minPWM;
  delay(2000);
  OCR2A = 0;
  delay(2000);
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.println("slowUP");
  slowUp(random(OCR2A, maxPWM), 15);
  delay(2000);
  Serial.println("slowDown");
  slowDown(random(minPWM, OCR2A), 15);
  delay(2000);
  if (counter == 0){
    direction = false;
    setDir(direction);
  }
  counter++;
  if (counter==10) {
    direction = true;
    setDir(direction);
    counter = 0;
  }
}

void setDir(bool dir) {
  Serial.print("Direction: ");
  if(dir){
    Serial.println("<=");
  }
  else {
    Serial.println("=>");
  }
  
  slowDown(0, 5);
  digitalWrite(PWM, 0);
  delay(100);
  if (dir) {
    digitalWrite(left, 0);
    digitalWrite(right, 1);
  }
  else {
    digitalWrite(right, 0);
    digitalWrite(left, 1);
  }
  delay(2000);
  TCCR2A = 0b10100011;
  TCCR2B = 0b00000010;
  OCR2A = 0;
}

void setSpeed(int value) {
  if (value > 254) {
    value = 254;
  }
  OCR2A = value;
}

void slowUp(int value, int d) {
  if (value > 254) {
    value = 254;
  }
  if (value < minPWM) {
    value = minPWM;
  }
  Serial.print("UpValue: ");
  Serial.println(value);
  for (int i = OCR2A; i <= value + 1; i++) {
    OCR2A = i;
    delay(d);
  }
}

void slowDown(int value, int d) {
  if (value != 0) {
    if (value < minPWM) {
      value = minPWM;
    }
  }
  Serial.print("DownValue: ");
  Serial.println(value);
  for (int i = OCR2A; i != value - 1; i--) {
    if (OCR2A < value) {
      break;
    }
    OCR2A = i;
    delay(d);
  }
}