/**************************************************************************\
* Pinoccio Library                                                         *
* https://github.com/Pinoccio/library-pinoccio                             *
* Copyright (c) 2012-2014, Pinoccio Inc. All rights reserved.              *
* ------------------------------------------------------------------------ *
*  This program is free software; you can redistribute it and/or modify it *
*  under the terms of the BSD License as described in license.txt.         *
\**************************************************************************/
// Class for communicating using the Pinoccio Backpack Bus protocol
#ifndef LIB_PINOCCIO_PBBP_H
#define LIB_PINOCCIO_PBBP_H

#include <stdint.h>
#include <Print.h>

class PBBP {
public:
  PBBP();
  void begin(uint8_t pin);
  bool enumerate(void (*callback)(uint8_t*));
  bool sendReset();
  bool sendByte(uint8_t b);
  bool sendBytes(const uint8_t *buf, uint8_t len);
  bool receiveByte(uint8_t *b);
  bool receiveBytes(uint8_t *buf, uint8_t len);

  // Sends a reset, addresses the slave and sends the given command. Any
  // subsequent data transfers should just use sendByte(s) /
  // receiveByte(s) directly
  bool sendCommand(uint8_t slave_addr, uint8_t command);

  bool readEeprom(uint8_t slave_addr, uint8_t eeprom_addr, uint8_t *buf, uint8_t len);
  bool writeEeprom(uint8_t slave_addr, uint8_t eeprom_addr, const uint8_t *buf, uint8_t len);

  void printLastError(Print &p);

  enum error {
    OK,
    STALL_TIMEOUT,
    TIMEOUT,
    NACK,
    // NACK received, but failed to receive error code
    NACK_NO_SLAVE_CODE,
    NO_ACK_OR_NACK,
    ACK_AND_NACK,
    PARITY_ERROR,
    BIT_TOO_LATE,
    // CRC error in a received unique id
    CRC_ERROR,
    // More slaves than available addresses
    TOO_MANY_SLAVES,
  };

  // Last error that occured. Only valid when the last method called
  // returned false.
  error last_error;

  // If last_error is NACK, this is the error code sent by the
  // slave
  uint8_t last_slave_error;

  static const uint8_t UNIQUE_ID_LENGTH = 8;
  static const uint8_t UNIQUE_ID_CRC_POLY = 0x2f;

protected:
  bool waitForFreeBus();
  bool waitForNextBitStart();
  bool sendBit(bool value);
  bool receiveBit(bool *value);
  bool receiveReady();
  bool receiveAck();

  uint8_t pin;

  // The start time (in micros) of the current or previous bit
  unsigned long bit_start;
  // The end time (in micros) of the previous bit
  unsigned long bit_end;

  static const uint16_t reset_time = 2500;
  static const uint16_t start_time = 125;
  static const uint16_t value_time = 650;
  static const uint16_t sample_time = 350;
  static const uint16_t idle_time = 50;
  static const uint16_t next_bit_time = 700;
  static const uint16_t max_next_bit_time = 1100;

  static const uint8_t max_stall_bits = 20;

  static const uint8_t max_slaves = 127;

  static const char *error_code_str[];
};

#endif // LIB_PINOCCIO_PBBP_H

/* vim: set filetype=cpp sw=2 sts=2 expandtab: */