#pragma once
//
//    FILE: MCP23S08.h
//  AUTHOR: Rob Tillaart
// VERSION: 0.1.1
// PURPOSE: Arduino library for SPI MCP23S08 8 channel port expander
//    DATE: 2022-01-10
//     URL: https://github.com/RobTillaart/MCP23S08


#include "Arduino.h"
#include "SPI.h"


#define MCP23S08_LIB_VERSION              (F("0.1.1"))

#define MCP23S08_OK                       0x00
#define MCP23S08_PIN_ERROR                0x81
#define MCP23S08_SPI_ERROR                0x82
#define MCP23S08_VALUE_ERROR              0x83
#define MCP23S08_PORT_ERROR               0x84
#define MCP23S08_REGISTER_ERROR           0xFF

#define MCP23S08_INVALID_READ             -100


class MCP23S08
{
public:
  MCP23S08(uint8_t select, uint8_t dataIn, uint8_t dataOut, uint8_t clock, uint8_t address = 0x00);
  MCP23S08(uint8_t select, uint8_t address = 0x00);

  bool     begin();
  bool     isConnected();  // needed ?


  //  single pin interface
  //  mode = INPUT, OUTPUT or INPUT_PULLUP (==INPUT)
  bool     pinMode(uint8_t pin, uint8_t mode);
  bool     digitalWrite(uint8_t pin, uint8_t value);
  uint8_t  digitalRead(uint8_t pin);

  bool     setPolarity(uint8_t pin, bool reversed);
  bool     getPolarity(uint8_t pin, bool &reversed);
  bool     setPullup(uint8_t pin, bool pullup);
  bool     getPullup(uint8_t pin, bool &pullup);


  //  8 pins interface
  //  port  = 0..1
  //  value = bit pattern
  bool     pinMode8(uint8_t value);
  bool     write8(uint8_t value);
  int      read8();

  bool     setPolarity8(uint8_t mask);
  bool     getPolarity8(uint8_t &mask);
  bool     setPullup8(uint8_t mask);
  bool     getPullup8(uint8_t &mask);


  //       speed in Hz
  void     setSPIspeed(uint32_t speed);
  uint32_t getSPIspeed() { return _SPIspeed; };

  //       debugging
  bool     usesHWSPI() { return _hwSPI; };
  int      lastError();

private:
  bool     writeReg(uint8_t reg, uint8_t value);
  uint8_t  readReg(uint8_t reg);

  uint8_t  _address = 0;
  uint8_t  _select  = 0;
  uint8_t  _dataOut = 0;
  uint8_t  _dataIn  = 0;
  uint8_t  _clock   = 0;
  uint8_t  _error   = MCP23S08_OK;

  bool        _hwSPI = false;
  //  1 MHz is a safe value TODO CHECK datasheet
  uint32_t    _SPIspeed = 8000000UL;   
  SPIClass    * mySPI;
  SPISettings _spi_settings;

  uint8_t  swSPI_transfer(uint8_t val);
};


// -- END OF FILE --