// **********************************************************************************
// Driver definition for HopeRF RFM69W/RFM69HW/RFM69CW/RFM69HCW, Semtech SX1231/1231H
// **********************************************************************************
// Copyright Felix Rusu (2014), felix@lowpowerlab.com
// http://lowpowerlab.com/
// **********************************************************************************
// License
// **********************************************************************************
// This program is free software; you can redistribute it 
// and/or modify it under the terms of the GNU General    
// Public License as published by the Free Software       
// Foundation; either version 2 of the License, or        
// (at your option) any later version.                    
//                                                        
// This program is distributed in the hope that it will   
// be useful, but WITHOUT ANY WARRANTY; without even the  
// implied warranty of MERCHANTABILITY or FITNESS FOR A   
// PARTICULAR PURPOSE.  See the GNU General Public        
// License for more details.                              
//                                                        
// You should have received a copy of the GNU General    
// Public License along with this program; if not, write 
// to the Free Software Foundation, Inc.,                
// 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
//                                                        
// Licence can be viewed at                               
// http://www.fsf.org/licenses/gpl.txt                    
//
// Please maintain this license information along with authorship
// and copyright notices in any redistribution of this code
// **********************************************************************************
#ifndef RFM69_h
#define RFM69_h
#include <Arduino.h>            //assumes Arduino IDE v1.0 or greater

#define DISABLE_RSSI_CHECK  0

#define RF69_MAX_DATA_LEN         61 // to take advantage of the built in AES/CRC we want to limit the frame size to the internal FIFO size (66 bytes - 3 bytes overhead)
#define RF69_SPI_CS               SS // SS is the SPI slave select pin, for instance D10 on atmega328

// INT0 on AVRs should be connected to RFM69's DIO0 (ex on Atmega328 it's D2, on Atmega644/1284 it's D2)
#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega328P__) || defined(__AVR_ATmega88) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega88__)
  #define RF69_IRQ_PIN          2
  #define RF69_IRQ_NUM          0
#elif defined(__AVR_ATmega644P__) || defined(__AVR_ATmega1284P__)
  #define RF69_IRQ_PIN          2
  #define RF69_IRQ_NUM          2
#endif

#define CSMA_LIMIT          -90 // upper RX signal sensitivity threshold in dBm for carrier sense access
#define RF69_MODE_SLEEP       0 // XTAL OFF
#define	RF69_MODE_STANDBY     1 // XTAL ON
#define RF69_MODE_SYNTH	      2 // PLL ON
#define RF69_MODE_RX          3 // RX MODE
#define RF69_MODE_TX		      4 // TX MODE

//available frequency bands
#define RF69_315MHZ     31  // non trivial values to avoid misconfiguration
#define RF69_433MHZ     43
#define RF69_868MHZ     86
#define RF69_915MHZ     91

#define null                  0
#define COURSE_TEMP_COEF    -90 // puts the temperature reading in the ballpark, user can fine tune the returned value
#define RF69_BROADCAST_ADDR 255
#define RF69_CSMA_LIMIT_MS 1000

class RFM69 {
  public:
    static volatile byte DATA[RF69_MAX_DATA_LEN];          // recv/xmit buf, including hdr & crc bytes
    static volatile byte DATALEN;
    static volatile byte SENDERID;
    static volatile byte TARGETID; //should match _address
    static volatile byte PAYLOADLEN;
    static volatile byte ACK_REQUESTED;
    static volatile byte ACK_RECEIVED; /// Should be polled immediately after sending a packet with ACK request
    static volatile int RSSI; //most accurate RSSI during reception (closest to the reception)
    static volatile byte _mode; //should be protected?
    
    RFM69(byte slaveSelectPin=RF69_SPI_CS, byte interruptPin=RF69_IRQ_PIN, bool isRFM69HW=false, byte interruptNum=RF69_IRQ_NUM) {
      _slaveSelectPin = slaveSelectPin;
      _interruptPin = interruptPin;
      _interruptNum = interruptNum;
      _mode = RF69_MODE_STANDBY;
      _promiscuousMode = false;
      _powerLevel = 31;
      _isRFM69HW = isRFM69HW;
    }

    bool initialize(byte freqBand, byte ID, byte networkID=1);
    void setAddress(byte addr);
    bool canSend();
    void send(byte toAddress, const void* buffer, byte bufferSize, bool requestACK=false);
    bool sendWithRetry(byte toAddress, const void* buffer, byte bufferSize, byte retries=2, byte retryWaitTime=40); //40ms roundtrip req for  61byte packets
    void receiveStart();
    bool receiveDone();
    bool ACKReceived(byte fromNodeID);
    bool ACKRequested();
    void sendACK(const void* buffer = "", uint8_t bufferSize=0);
    void setFrequency(uint32_t FRF);
    void encrypt(const char* key);
    void setCS(byte newSPISlaveSelect);
    int readRSSI(bool forceTrigger=false);
    void promiscuous(bool onOff=true);
    void setHighPower(bool onOFF=true); //have to call it after initialize for RFM69HW
    void setPowerLevel(byte level); //reduce/increase transmit power level
    void sleep();
    byte readTemperature(byte calFactor=0); //get CMOS temperature (8bit)
    void rcCalibration(); //calibrate the internal RC oscillator for use in wide temperature variations - see datasheet section [4.3.5. RC Timer Accuracy]

    // allow hacking registers by making these public
    byte readReg(byte addr);
    void writeReg(byte addr, byte val);
    void readAllRegs();

  protected:
    static void isr0();
    void virtual interruptHandler();
    void sendFrame(byte toAddress, const void* buffer, byte size, bool requestACK=false, bool sendACK=false);

    static RFM69* selfPointer;
    byte _slaveSelectPin;
    byte _interruptPin;
    byte _interruptNum;
    byte _address;
    bool _promiscuousMode;
    byte _powerLevel;
    bool _isRFM69HW;
    byte _SPCR;
    byte _SPSR;

    void receiveBegin();
    void setMode(byte mode);
    void setHighPowerRegs(bool onOff);
    void select();
    void unselect();
};

#endif