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aentingeraentinger
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Add HardwareCAN - a abstract base class for implementing CAN interfaces across Arduino cores.
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‎api/CanMsg.h

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/*
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* This file is free software; you can redistribute it and/or modify
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* it under the terms of either the GNU General Public License version 2
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* or the GNU Lesser General Public License version 2.1, both as
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* published by the Free Software Foundation.
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*/
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#ifndef ARDUINOCORE_API_CAN_MSG_H_
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#define ARDUINOCORE_API_CAN_MSG_H_
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/**************************************************************************************
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* INCLUDE
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**************************************************************************************/
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#include <cstdlib>
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#include <cstdint>
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#include <cstring>
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#include <Arduino.h>
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/**************************************************************************************
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* NAMESPACE
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**************************************************************************************/
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namespace arduino
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{
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/**************************************************************************************
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* CLASS DECLARATION
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**************************************************************************************/
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class CanMsg : public Printable
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{
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public:
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static size_t constexpr MAX_DATA_LENGTH = 8;
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CanMsg(uint32_t const can_id, uint8_t const can_data_len, uint8_t const * can_data_ptr)
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: id{can_id}
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, data_length{can_data_len}
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, data{0}
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{
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memcpy(data, can_data_ptr, min(can_data_len, MAX_DATA_LENGTH));
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}
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CanMsg() : CanMsg(0, 0, nullptr) { }
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CanMsg(CanMsg const & other)
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{
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this->id = other.id;
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this->data_length = other.data_length;
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memcpy(this->data, other.data, this->data_length);
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}
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virtual ~CanMsg() { }
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void operator = (CanMsg const & other)
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{
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if (this == &other)
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return;
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this->id = other.id;
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this->data_length = other.data_length;
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memcpy(this->data, other.data, this->data_length);
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}
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virtual size_t printTo(Print & p) const override
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{
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char buf[20] = {0};
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size_t len = 0;
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/* Print the header. */
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len = snprintf(buf, sizeof(buf), "[%08X] (%d) : ", id, data_length);
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size_t n = p.write(buf, len);
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/* Print the data. */
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for (size_t d = 0; d < data_length; d++)
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{
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len = snprintf(buf, sizeof(buf), "%02X", data[d]);
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n += p.write(buf, len);
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}
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/* Wrap up. */
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return n;
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}
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uint32_t id;
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uint8_t data_length;
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uint8_t data[MAX_DATA_LENGTH];
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};
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/**************************************************************************************
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* NAMESPACE
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**************************************************************************************/
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} /* arduino */
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#endif /* ARDUINOCORE_API_CAN_MSG_H_ */

‎api/CanMsgRingbuffer.cpp

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/*
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* This file is free software; you can redistribute it and/or modify
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* it under the terms of either the GNU General Public License version 2
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* or the GNU Lesser General Public License version 2.1, both as
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* published by the Free Software Foundation.
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*/
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/**************************************************************************************
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* INCLUDE
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**************************************************************************************/
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#include "CanMsgRingbuffer.h"
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/**************************************************************************************
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* NAMESPACE
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**************************************************************************************/
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namespace arduino
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{
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/**************************************************************************************
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* CTOR/DTOR
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**************************************************************************************/
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CanMsgRingbuffer::CanMsgRingbuffer()
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: _head{0}
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, _tail{0}
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, _num_elems{0}
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{
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}
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/**************************************************************************************
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* PUBLIC MEMBER FUNCTIONS
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**************************************************************************************/
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void CanMsgRingbuffer::enqueue(CanMsg const & msg)
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{
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if (isFull())
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return;
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_buf[_head] = msg;
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_head = next(_head);
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_num_elems++;
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}
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CanMsg CanMsgRingbuffer::dequeue()
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{
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if (isEmpty())
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return CanMsg();
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CanMsg const msg = _buf[_tail];
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_tail = next(_tail);
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_num_elems--;
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return msg;
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}
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/**************************************************************************************
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* NAMESPACE
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**************************************************************************************/
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} /* arduino */

‎api/CanMsgRingbuffer.h

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/*
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* This file is free software; you can redistribute it and/or modify
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* it under the terms of either the GNU General Public License version 2
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* or the GNU Lesser General Public License version 2.1, both as
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* published by the Free Software Foundation.
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*/
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#ifndef ARDUINOCORE_API_CAN_MSG_RING_BUFFER_H_
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#define ARDUINOCORE_API_CAN_MSG_RING_BUFFER_H_
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/**************************************************************************************
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* INCLUDE
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**************************************************************************************/
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#include <cstdint>
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#include "CanMsg.h"
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/**************************************************************************************
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* NAMESPACE
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**************************************************************************************/
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namespace arduino
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{
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/**************************************************************************************
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* CLASS DECLARATION
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**************************************************************************************/
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class CanMsgRingbuffer
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{
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public:
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static size_t constexpr RING_BUFFER_SIZE = 32U;
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CanMsgRingbuffer();
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inline bool isFull() const { return (_num_elems == RING_BUFFER_SIZE); }
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void enqueue(CanMsg const & msg);
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inline bool isEmpty() const { return (_num_elems == 0); }
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CanMsg dequeue();
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inline size_t available() const { return _num_elems; }
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private:
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CanMsg _buf[RING_BUFFER_SIZE];
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volatile size_t _head;
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volatile size_t _tail;
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volatile size_t _num_elems;
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inline size_t next(size_t const idx) const { return ((idx + 1) % RING_BUFFER_SIZE); }
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};
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/**************************************************************************************
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* NAMESPACE
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**************************************************************************************/
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} /* arduino */
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#endif /* ARDUINOCORE_API_CAN_MSG_RING_BUFFER_H_ */

‎api/HardwareCAN.h

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/*
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* This file is free software; you can redistribute it and/or modify
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* it under the terms of either the GNU General Public License version 2
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* or the GNU Lesser General Public License version 2.1, both as
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* published by the Free Software Foundation.
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*/
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#ifndef ARDUINOCORE_API_HARDWARECAN_H
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#define ARDUINOCORE_API_HARDWARECAN_H
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/**************************************************************************************
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* INCLUDE
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**************************************************************************************/
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#include "CanMsg.h"
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#include "CanMsgRingbuffer.h"
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/**************************************************************************************
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* TYPEDEF
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**************************************************************************************/
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enum class CanBitRate : int
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{
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BR_125k = 125000,
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BR_250k = 250000,
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BR_500k = 500000,
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BR_1000k = 1000000,
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};
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/**************************************************************************************
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* NAMESPACE
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**************************************************************************************/
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namespace arduino
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{
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/**************************************************************************************
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* CLASS DECLARATION
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**************************************************************************************/
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class HardwareCAN
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{
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public:
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virtual ~HardwareCAN() {}
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virtual bool begin(CanBitRate const can_bitrate) = 0;
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virtual void end() = 0;
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virtual int write(CanMsg const &msg) = 0;
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virtual size_t available() = 0;
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virtual CanMsg read() = 0;
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};
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/**************************************************************************************
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* NAMESPACE
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**************************************************************************************/
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} /* arduino */
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#endif /* ARDUINOCORE_API_HARDWARECAN_H */

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