HardwareI2C_FTDI.h

#pragma once
/*
  HardwareI2C_FTDI.h 
  Copyright (c) 2025 Phil Schatzmann. All right reserved.
 
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
 
  This library 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
  Lesser General Public License for more details.
 
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifdef USE_FTDI
#include <inttypes.h>
#include <ftdi.h>
// Undefine DEPRECATED macro from libftdi1 to avoid conflict with Arduino API
#ifdef DEPRECATED
#undef DEPRECATED
#endif
 
#include "api/Common.h"
#include "api/HardwareI2C.h"
#include "api/Stream.h"
 
namespace arduino {
 
class HardwareI2C_FTDI : public HardwareI2C {
 public:
  HardwareI2C_FTDI(int channel = 0);
 
  ~HardwareI2C_FTDI();
 
  bool begin(int vendor_id = 0x0403, int product_id = 0x6010, 
            const char* description = nullptr, const char* serial = nullptr);
 
  void begin() override { begin(0x0403, 0x6010); }
 
  void begin(uint8_t address) override;
 
  void end() override;
 
  void setClock(uint32_t freq) override;
 
  void beginTransmission(uint8_t address) override;
 
  size_t write(uint8_t data) override;
 
  size_t write(const uint8_t* data, size_t len) override;
 
  uint8_t endTransmission(bool stopBit = true) override;
  
  uint8_t endTransmission(void) override;
 
  size_t requestFrom(uint8_t address, size_t quantity, bool stopBit = true) override;
  size_t requestFrom(uint8_t address, size_t quantity) override;
 
  int available() override;
 
  int peek() override;
 
  int read() override;
 
  void flush() override;
 
  void onReceive(void(*function)(int)) override;
 
  void onRequest(void(*function)(void)) override;
 
  operator bool() { return is_open && ftdi_context != nullptr; }
 
 protected:
  struct ftdi_context* ftdi_context = nullptr;
  int ftdi_channel = 0;  // 0 for Channel A, 1 for Channel B
  bool is_open = false;
  
  // I2C state
  uint8_t current_slave_address = 0;
  uint32_t i2c_clock_frequency = 100000;  // Default 100kHz
  
  // Transmission buffer
  uint8_t tx_buffer[32];  // Buffer for outgoing data
  size_t tx_buffer_length = 0;
  
  // Receive buffer
  uint8_t rx_buffer[32];  // Buffer for incoming data
  size_t rx_buffer_length = 0;
  size_t rx_buffer_index = 0;
  
  // MPSSE I2C command constants
  static const uint8_t I2C_DATA_SHIFT_OUT = 0x11;
  static const uint8_t I2C_DATA_SHIFT_IN = 0x24;
  static const uint8_t I2C_DATA_SHIFT_OUT_IN = 0x31;
  static const uint8_t I2C_SET_DATA_BITS_LOW_BYTE = 0x80;
  static const uint8_t I2C_SET_DATA_BITS_HIGH_BYTE = 0x82;
  static const uint8_t I2C_GET_DATA_BITS_LOW_BYTE = 0x81;
  static const uint8_t I2C_GET_DATA_BITS_HIGH_BYTE = 0x83;
 
  // Pin assignments for I2C on ADBUS
  static const uint8_t SCL_BIT = 0;   // ADBUS0
  static const uint8_t SDA_OUT_BIT = 1; // ADBUS1
  static const uint8_t SDA_IN_BIT = 2;  // ADBUS2
 
  bool configureMPSSE();
 
  bool setClockFrequency(uint32_t frequency);
 
  bool sendStart();
 
  bool sendStop();
 
  bool sendRepeatedStart();
 
  bool sendByteCheckAck(uint8_t data);
 
  uint8_t receiveByteSendAck(bool send_ack);
 
  int sendData(const uint8_t* data, size_t length);
 
  int receiveData(uint8_t* data, size_t length);
 
  bool setLineStates(bool sda_state, bool scl_state);
};
 
}  // namespace arduino
 
#endif  // USE_FTDI