  *  Features:
  *    load/save VWC boundry value at EEPROM address 0 ( size = 2* int )
  *    Press button to start/stop calibrate mode. 
- *    Calibrating with LED on
+ *    Calibrating with LED blinking
  *  
  *  Connection: 
  *    Button : D2, default high


  for(int i=0;i<VWC_CNT;i++){
    val[i] = analogRead(pin_vwc[i]); //connect sensor to Analog 0
    if( mode == 1 ){
      if(val[i]> bound[i].v_top) bound[i].v_top = val[i];
      if(val[i]< bound[i].v_down ) bound[i].v_down = val[i];
    }
  
    vwc[i] = 1.0-((float(val[i])-bound[i].v_down)/(bound[i].v_top-bound[i].v_down));

  Serial.print(val[i]); Serial.print(",");
  Serial.print(vwc[i]*100); Serial.print(",");
  Serial.print(bound[i].v_down); Serial.print(",");
  Serial.print(bound[i].v_top); Serial.print(" ");
  if(i != VWC_CNT-1 ) Serial.print(",");
  }
  Serial.println("");
    
}
int calibrate_complete_check(){
  int change_cnt =0;
  for(int i=0;i<VWC_CNT*2;i++){
    if(bound_change[i]==1){
      change_cnt++;
    }
  }
  if(change_cnt==6) return 1;
  else return 0;
}


void mode_check_and_run(){
  int btn_state;
  //detect if btn click
