#include <SoftwareSerial.h>
#include <avr/io.h>
#include <util/delay.h>

#define TX PA6
#define RX PA5

SoftwareSerial Serial(RX, TX);

int inA1 = PA0; // input 1 of the stepper
int inA2 = PA1; // input 2 of the stepper
int inB1 = PA3; // input 3 of the stepper
int inB2 = PA4; // input 4 of the stepper
int filter=0;

int stepDelay = 25; // Delay between steps in milliseconds

void setup()
{
 pinMode(inA1, OUTPUT);     
  pinMode(inA2, OUTPUT);     
  pinMode(inB1, OUTPUT);     
  pinMode(inB2, OUTPUT);   
  Serial.begin(9600);
}

void step1() {
  digitalWrite(inA1, LOW);   
  digitalWrite(inA2, HIGH);   
  digitalWrite(inB1, HIGH);   
  digitalWrite(inB2, LOW);   
  delay(stepDelay);
  
}
void step2() {
  digitalWrite(inA1, LOW);   
  digitalWrite(inA2, HIGH);   
  digitalWrite(inB1, LOW);   
  digitalWrite(inB2, HIGH);   
  delay(stepDelay);
}
void step3() {
  digitalWrite(inA1, HIGH);   
  digitalWrite(inA2, LOW);   
  digitalWrite(inB1, LOW);   
  digitalWrite(inB2, HIGH);   
  delay(stepDelay);
}
void step4() {
  digitalWrite(inA1, HIGH);   
  digitalWrite(inA2, LOW);   
  digitalWrite(inB1, HIGH);   
  digitalWrite(inB2, LOW);   
  delay(stepDelay);
}
void stopMotor() {
  digitalWrite(inA1, LOW);   
  digitalWrite(inA2, LOW);   
  digitalWrite(inB1, LOW);   
  digitalWrite(inB2, LOW);   
}

void loop()
{

if (Serial.available()>0)
{
int eps=0.5;
int low=Serial.read();
int high=Serial.read();
int value = (256*high) + low;
if (value > 511)
      value -= 1024;
int V = 2.5 - value*5.0/(20.0*512.0);
int R = 10000.0/(5.0/V-1.0);
int B = 3750.0;
int R25 =  10000.0;
int T = 1.0/(log(R/R25)/B+(1/(22.0+273.15))) - 273.15;
filter = (1-eps)*filter + eps*T;
Serial.print(filter);

if (filter==26.8)             
{
  //for (int i=0; i<=11; i++)
  //{
  step1();
  step2();
  step3();
  step4();
  //}
}
else stopMotor();
}
else stopMotor();
}