sfDevFPC2534I2C.h

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/*
 *---------------------------------------------------------------------------------
 *
 * Copyright (c) 2025, SparkFun Electronics Inc.
 *
 * SPDX-License-Identifier: MIT
 *
 *---------------------------------------------------------------------------------
 */
 
#pragma once
 
// from the FPC SDK
#include "fpc_api.h"
 
#include <Arduino.h>
#include <Wire.h>
 
#include "sfDevFPC2534IComm.h"
 
// The default I2C address for the FPC2534
const uint8_t kFPC2534DefaultAddress = 0x24;
 
// Define an interface to perform the needed read actions for the I2C protocol - this is needed since
// the FPC2534 uses a custom I2C read protocol that the standard Arduino Wire library does not support.
//
class sfDevFPC2534I2C_IRead
{
  public:
    virtual void initialize(uint8_t i2cBusNumber) = 0;
    virtual uint16_t readPayload(size_t len, uint8_t *data) = 0;
    virtual uint16_t readTransferSize(uint8_t device_address) = 0;
};
 
// i2c impl for the FPC2534 communication interface
 
class sfDevFPC2534I2C : public sfDevFPC2534IComm
{
  public:
    sfDevFPC2534I2C();
    bool initialize(uint8_t address, TwoWire &wirePort, uint8_t i2cBusNumber, uint32_t interruptPin);
    bool dataAvailable();
    void clearData();
    uint16_t write(const uint8_t *data, size_t len);
    uint16_t read(uint8_t *data, size_t len);
 
  private:
    bool fifo_enqueue(uint8_t *data, size_t len);
    bool fifo_dequeue(uint8_t *data, size_t len);
 
    uint8_t _i2cAddress;
    TwoWire *_i2cPort;
    uint8_t _i2cBusNumber;
 
    // Internal data buffer items
    static constexpr size_t kDataBufferSize = 2048;
 
    uint8_t _dataBuffer[kDataBufferSize];
 
    // using a circular buffer ...
    uint16_t _dataHead;
    uint16_t _dataTail;
    uint16_t _dataCount;
};