#include <Wire.h>
const int MPU_addr = 0x68;
int16_t AcX,AcY,AcZ;
int counter;
int16_t all_axis[3][100];
int16_t axis_select;
int16_t minX, maxX, minY, maxY, minZ, maxZ;
int steps;
bool flag;
unsigned long Time;
int avx;
void setup() {
 Wire.begin();
  Wire.beginTransmission(MPU_addr);
  Wire.write(0x6B);  // PWR_MGMT_1 register
  Wire.write(0);     // set to zero (wakes up the MPU-6050)
  axis_select = 2;
  flag = false;
  Time = millis();
  minX = 32000; maxX = -32000; minY = 32000; maxY =  -32000;
  minZ = 32000; maxZ = -32000;
  Wire.endTransmission(true);
  Serial.begin(9600);

}


void loop() {
  // put your main code here, to run repeatedly:
  Wire.beginTransmission(MPU_addr);
  Wire.write(0x3B);  // starting with register 0x3B (ACCEL_XOUT_H)
  Wire.endTransmission(false);
  Wire.requestFrom(MPU_addr,14,true);
  all_axis[0][counter%100]=AcX=Wire.read()<<8|Wire.read();  // 0x3B (ACCEL_XOUT_H) & 0x3C (ACCEL_XOUT_L)
  //Serial.println(AcZ);
  all_axis[1][counter%100]=AcY=Wire.read()<<8|Wire.read();  // 0x3D (ACCEL_YOUT_H) & 0x3E (ACCEL_YOUT_L)
  all_axis[2][counter%100]=AcZ=Wire.read()<<8|Wire.read();  // 0x3F (ACCEL_ZOUT_H) & 0x40 (ACCEL_ZOUT_L)
  counter++;
  //Serial.println(counter);
  if(AcX > maxX)
    maxX = AcX;
  else if(AcX < minX)
    minX = AcX;

  if(AcY > maxY)
    maxY = AcY;
  else if(AcY < minY)
    minY = AcY;

   if(AcZ > maxZ)
    maxZ = AcZ;
  else if(AcZ < minZ)
    minZ = AcZ;

avx=(maxZ+minZ)/2;
 /* if(counter % 20 == 0){
    if(maxX - minX > maxY - minY && maxX - minX > maxZ - minZ){
      axis_select = 0;
      avx=(maxX + minX)/2;}
    else if(maxY - minY > maxX - minX && maxY - minY > maxZ - minZ){
      axis_select = 1;
      avx=(maxY+minY)/2;}
    else if(maxZ - minZ > maxY - minY && maxZ - minZ > maxX - minX){
      axis_select = 2;
      avx=(maxZ+minZ)/2;}
  }
  */
//Serial.println(axis_select);
//Serial.println("avx");
//Serial.println(avx);
  if(counter % 15 == 0 && counter > 22){
    int average1 = 0, average2 = 0;
    for(int i =counter; counter-i < 15; i=(i-1+100)%100){
      average1 += all_axis[axis_select][i];
      average2 += all_axis[axis_select][i-1];
    }
     Serial.println(average2/15);
    int diff = average2 - average1;
    if(diff < 0 && !flag && millis() - Time > 50&&average2/15>avx){
      steps++;
      Serial.println("steps---------------------------------");

      flag = true;
      Time = millis();
    } else if(diff > 0&& average2/15<avx){
      flag = false;
    }
  }

  //Serial.print16_t(AcX);
  //Serial.print16_t(',');
  //Serial.print16_t(AcY);
  //Serial.print16_t(',');
  //Serial.print16_tln(AcZ);

  delay(10);
}