/*--------------------------------------------------------------------------------------------------
 Abfrage und Setting: 
  Setting PulseProUmdrehung (Anzahl der Zahnradzähne):
  > CAN-ID = 630; message = FF 10 (Datenbyte 0 muss FF sein, Datenbyte 1 enthält die Pulsanzahl) 

  Abfrage des Settings PulseProUmdrehung:
  > CAN-ID = 630; message = FF 00

Sende-IDs:
> 0x631 = rpm
> 0x632 = Wert PulseProUmdrehung (Anzahl der Zahnradzähne) Setting

 ---------------------------------------------------------------------------------------------------*/
#include <Canbus.h>
#include <mcp2515.h>
#include <defaults.h>
#include <mcp2515_defs.h>
#include <global.h>
#include <EEPROM.h>

 volatile uint8_t pulse; //gezählte Pulse
 volatile uint16_t  Capt1, Capt2,// timeStamp1, timeStamp2, //VARIABLES TO HOLD TIMESTAMPS
                    rpm,                //Wert Drehzahl in rpm
                    ID = 631,           // CAN ID
                    zeit_low,           // Timer1-Anteil
                    zeit_high,          // T1 Ueberlauf-Anteil
                    ueberlauf=0,        // Zähler Überlauf
                    ueberlauf_count=0;        // Anzahl Überläufe bei einer Umdrehung
                    //mess_dauer,         // minimale Wartezeit

 volatile uint32_t zeit_diff, timeStamp1, timeStamp2;
 
 int PulseProUmdrehung;// = 24;

 #define ledPin 3 //PD3 steuert LED an
 #define icpPin 8 // PB0 ICP D8 Interrupt input


 /*--------------------------------------------------------------------------------------------------
 INIT FUNCTION
 ---------------------------------------------------------------------------------------------------*/
void Init (void)
{
  pinMode(ledPin, OUTPUT);
  pinMode(icpPin,INPUT);
  digitalWrite(icpPin,HIGH); //pull up
  Serial.begin(115200);
  Serial.println("Bereit");
  PulseProUmdrehung = EEPROM.read(0);
  Serial.print("PulseProUmdrehung ");
  Serial.println(PulseProUmdrehung);
}

void CAN_500 (void)
{
  PulseProUmdrehung = EEPROM.read(0);

  if(Canbus.init(CANSPEED_500))  //Initialise MCP2515 CAN controller at the specified speed
  {
    Serial.println("CAN Init ok 500 kBit/s");
  }
  else
  {
    Serial.println("Can't init CAN");
}}

void CAN_250 (void)
{
  if(Canbus.init(CANSPEED_250))  //Initialise MCP2515 CAN controller at the specified speed
  {
    Serial.println("CAN Init ok 250 kBit/s");
  }
  else
  {
    Serial.println("Can't init CAN");
}}
 
 /*--------------------------------------------------------------------------------------------------
 INTIALIZING TIMER
 ---------------------------------------------------------------------------------------------------*/
 void InitTimer1(void)
 {
 TCNT1=0; //SETTING INTIAL TIMER VALUE
 TCCR1B|=(1<<ICES1); //SETTING FIRST CAPTURE ON RISING EDGE 
 TIMSK1|=(1<<ICIE1)|(0<<TOIE1); //ENABLING INPUT CAPTURE AND OVERFLOW INTERRUPTS
 }
 /*--------------------------------------------------------------------------------------------------
 STARTING TIMER
 ---------------------------------------------------------------------------------------------------*/
 void StartTimer1(void)
 {
 TCCR1B|=(1<<CS12); //STARTING TIMER WITH PRESCALER 256
 }
 /*--------------------------------------------------------------------------------------------------
 CAPTURE ISR
 ---------------------------------------------------------------------------------------------------*/
unsigned long timeStampAkt, timeStampLast;//, zeit_diff;
 
 ISR(TIMER1_CAPT_vect)
 {
   if (pulse == 0)
   {
      timeStampLast = ICR1;
   }
   pulse++; //INCREMENTING FLAG
   if (pulse == PulseProUmdrehung)
   {
      timeStampAkt = ICR1;
      timeStampAkt = (ueberlauf_count<<16) + ICR1; // aus ICP und Überlaufz. einen 32 Bit Zähler basteln
      rpm = 3750000 / (timeStampAkt-timeStampLast); // Magic Number 3750000 = 60000/0.016
      ueberlauf_count=0;
      pulse = 0;
   }
} 

 /*--------------------------------------------------------------------------------------------------
 OVF ISR
 ---------------------------------------------------------------------------------------------------*/
ISR(TIMER1_OVF_vect)        
{
  ueberlauf_count++;      // Ueberlaeufe von T1 ergeben obere 16bit der Messzeit
}
 /*--------------------------------------------------------------------------------------------------
 MAIN FUNCTION
 ---------------------------------------------------------------------------------------------------*/
int main (void)  {
  
 InitTimer1(); //CALLING FUNCTION INITTIMER1 TO INITIALIZE TIMER 1
 StartTimer1(); //CALLING FUNCTION STARTTIMER1 TO START TIMER 1
 sei(); //ENABLING GLOBAL INTERRUPTS
 Init();
 if(EEPROM.read(1) == 25)
    {
      CAN_250();
    }
  else 
    {
      CAN_500();
    }
 
 while(1) {

    tCAN message;
    if (mcp2515_check_message()) 
      {
        if (mcp2515_get_message(&message)) 
        {
            if(message.id == 0x630 and message.data[0] == 0xFF)  //Die Pulsanzahl wird ins eeprom geschrieben und eingestellt
                 { 
                   message.id = 0x632; //formatted in HEX         
                   EEPROM.write(0, 0); 
                   PulseProUmdrehung = message.data[1];
                   EEPROM.write(0, PulseProUmdrehung);    
                   Serial.print("PulseProUmdrehung ");
                   Serial.println(PulseProUmdrehung);
                   message.id = 0x632; //formatted in HEX
                   message.header.rtr = 0;
                   message.header.length = 2; //formatted in DEC
                   message.data[0] = PulseProUmdrehung;
                   message.data[1] = 0;
                   mcp2515_bit_modify(CANCTRL, (1<<REQOP2)|(1<<REQOP1)|(1<<REQOP0), 0);
                   mcp2515_send_message(&message);   
                 }   
            if(message.id == 0x630 and message.data[0] == 0xFE)  //Die Pulsanzahl wird abgefragt
                 {       
                   PulseProUmdrehung = EEPROM.read(0);      
                   Serial.print("PulseProUmdrehung ");
                   Serial.println(PulseProUmdrehung);
                   message.id = 0x632; //formatted in HEX
                   message.header.rtr = 0;
                   message.header.length = 2; //formatted in DEC
                   message.data[0] = PulseProUmdrehung;
                   message.data[1] = 0;
                   mcp2515_bit_modify(CANCTRL, (1<<REQOP2)|(1<<REQOP1)|(1<<REQOP0), 0);
                   mcp2515_send_message(&message);    
                 }         
             if(message.id == 0x630 and message.data[0] == 0xBB)  //Wahl der Bitrate
                 {       
                  if (message.data[1] == 0xBA)      //Bitrate = 250 kBits/s wird eingestellt
                   {
                     CAN_250();   
                     Serial.print("Bitrate ");
                     Serial.println("250 kbit/s");
                     EEPROM.write(1, 25); 
                   }
                 if (message.data[1] == 0xBF)       //Bitrate = 500 kBits/s wird eingestellt
                   {
                     CAN_500();     
                     Serial.print("Bitrate ");
                     Serial.println("500 kbit/s");
                     EEPROM.write(1, 50); 
                   }
                 }         
          }
  }
   
         Serial.print(" RPM: ");
         Serial.println(rpm);
        
         uint8_t byte0 = rpm / 100;
         uint8_t byte1 = (rpm - (byte0 * 100));           

         message.id = 0x631; //formatted in HEX
         message.header.rtr = 0;
         message.header.length = 2; //formatted in DEC
     
         message.data[0] = rpm;
         message.data[1] = (rpm>>8);

         mcp2515_bit_modify(CANCTRL, (1<<REQOP2)|(1<<REQOP1)|(1<<REQOP0), 0);
         mcp2515_send_message(&message);   
         sei(); //ENABLING GLOBAL INTERRUPTS       
    }
    return 0;
 }