lowobservable.coax/interface2/firmware/include/NewCoax.h

// Copyright (c) 2019, Andrew Kay
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

#pragma once

#define ERROR_TX_RECEIVER_ACTIVE -1

#define ERROR_RX_RECEIVER_ACTIVE -5
#define ERROR_RX_TIMEOUT -2
#define ERROR_RX_OVERFLOW -3

class NewCoaxReceiver;
class NewCoaxDataBus;

class NewCoaxTransmitter
{
public:
    NewCoaxTransmitter(NewCoaxDataBus &dataBus, NewCoaxReceiver &receiver) :
        _dataBus(dataBus), _receiver(receiver) { };

    void begin();
    int transmit(uint16_t *buffer, size_t bufferCount);

private:
    NewCoaxDataBus &_dataBus;
    NewCoaxReceiver &_receiver;

    void reset();
    void write(uint16_t word);
};

enum NewCoaxReceiverState { Disabled, Idle, Receiving, Received };

class NewCoaxReceiver
{
public:
    NewCoaxReceiver(NewCoaxDataBus &dataBus) : _dataBus(dataBus) { };

    void begin();
    void enable();
    void disable();
    int receive(uint16_t *buffer, size_t bufferSize, uint16_t timeout);
    void activeInterrupt();
    void dataAvailableInterrupt();
    void errorInterrupt();

private:
    NewCoaxDataBus &_dataBus;
    volatile NewCoaxReceiverState _state = Disabled;
    volatile uint16_t _error;
    volatile uint16_t *_buffer;
    volatile size_t _bufferSize;
    volatile int _bufferCount;

    void reset();
    uint16_t read();
};

class NewCoaxDataBus
{
public:
    void setMode(uint8_t mode, bool force);
    uint16_t read();
    void write(uint16_t word);

private:
    int _mode = -1;

    uint16_t encode(uint16_t word);
    uint16_t decode(uint16_t word);
};