com: Traditionally the first module of my libs is an i2c implementation
This commit is contained in:
Christos Houtouridis
parent
36f0494e8f
commit
f1a651926d
285
include/utl/com/i2c.h
Normal file
285
include/utl/com/i2c.h
Normal file
@ -0,0 +1,285 @@
|
|||||||
|
/*!
|
||||||
|
* \file /utl/com/i2c.h
|
||||||
|
* \brief An Abstract base class interface for the i2c bus
|
||||||
|
*
|
||||||
|
* Copyright (C) 2018 Christos Choutouridis
|
||||||
|
*
|
||||||
|
* This program 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 3
|
||||||
|
* of the License, or (at your option) any later version.
|
||||||
|
*
|
||||||
|
* This program 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 program. If not, see <http://www.gnu.org/licenses/>.
|
||||||
|
*
|
||||||
|
*/
|
||||||
|
#ifndef _utl_com_i2c_h__
|
||||||
|
#define _utl_com_i2c_h__
|
||||||
|
|
||||||
|
#include <utl/impl/impl.h>
|
||||||
|
#include <utl/helper/crtp.h>
|
||||||
|
#include <utl/meta/sfinae.h>
|
||||||
|
|
||||||
|
namespace utl {
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \ingroup Communication
|
||||||
|
* \brief Abstract base class for i2c bus
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* this class force a common interface for I2C communication
|
||||||
|
* protocol implementations using CRTP
|
||||||
|
* \param impl_t The CRTP type (the derived/implementation class typename).
|
||||||
|
*/
|
||||||
|
template <typename impl_t>
|
||||||
|
class i2c_i {
|
||||||
|
_CRTP_IMPL(impl_t);
|
||||||
|
|
||||||
|
public:
|
||||||
|
using type = i2c_i<impl_t>; //!< Export type as identity meta-function
|
||||||
|
//! I2C transmit/receive sequence
|
||||||
|
enum class Sequence {
|
||||||
|
BYTE =0, //!< Only read/write byte [8 clocks]
|
||||||
|
ACK, //!< Only send/receive ack [1 clock]
|
||||||
|
BYTEnACK //!< Read/Write byte and ack [9 clocks]
|
||||||
|
};
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name Object lifetime
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
protected:
|
||||||
|
i2c_i () = default; //!< Allow constructor from derived only
|
||||||
|
~i2c_i () = default; //!< Allow destructor from derived only
|
||||||
|
i2c_i (const type&) = delete; //!< No copies
|
||||||
|
type& operator= (const type&) = delete;
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name Implementation requirements
|
||||||
|
* \note
|
||||||
|
* In order for the implementation to have the following as private members
|
||||||
|
* it also need to declare this class as friend
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
//! uint32_t _frequency () const; < clock frequency of the bus [Hz]
|
||||||
|
//! void _frequency (uint32_t); < set clock frequency of the bus [Hz]
|
||||||
|
//! void _start(); < Send start functionality
|
||||||
|
//! void _stop(); < Send stop functionality
|
||||||
|
//! byte_t _read (bool ack, Sequence seq); < Receive a byte from the i2c bus.
|
||||||
|
//! bool _write (byte_t byte, Sequence seq);< Transmit a byte to the i2c bus.
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name Get/Set functions
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
public:
|
||||||
|
uint32_t frequency () const { return impl()._frequency (); } //!< \return clock frequency of the bus
|
||||||
|
void frequency (uint32_t f) { impl()._frequency (f); } //!< \brief set clock frequency of the bus
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name User functions
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
public:
|
||||||
|
void start() { impl()._start (); } //!< Send start functionality
|
||||||
|
void stop () { impl()._stop (); } //!< Send stop functionality
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Receive a byte from the i2c bus.
|
||||||
|
* \param ack Optional ack bit.
|
||||||
|
* \arg 1 ACK the reception
|
||||||
|
* \arg 0 Don't ACK the reception.
|
||||||
|
* \param seq The operation sequence to execute
|
||||||
|
* \arg Sequence::BYTE Receive only the byte, do not send ack clock
|
||||||
|
* \arg Sequence::ACK Send only the ack bit
|
||||||
|
* \arg Sequence::BYTEnACK Receive the byte and send the ack bit
|
||||||
|
* \return The byte received.
|
||||||
|
*/
|
||||||
|
byte_t read (bool ack, Sequence seq =Sequence::BYTEnACK) {
|
||||||
|
return impl()._read (ack, seq);
|
||||||
|
}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Transmit a byte to the i2c bus.
|
||||||
|
* \param byte The byte to send.
|
||||||
|
* \param seq The operation sequence to execute
|
||||||
|
* \arg Sequence::BYTE Transmit only the byte, do not read ack bit
|
||||||
|
* \arg Sequence::ACK Read only the ack bit
|
||||||
|
* \arg Sequence::BYTEnACK Transmit the byte and read the ack bit
|
||||||
|
* \return Slave's ACK bit
|
||||||
|
* \arg false Slave didn't ACK
|
||||||
|
* \arg true Slave did ACK
|
||||||
|
*/
|
||||||
|
bool write (byte_t byte, Sequence seq =Sequence::BYTEnACK) {
|
||||||
|
return impl()._write (byte, seq);
|
||||||
|
}
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
};
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* A virtual base class specialization
|
||||||
|
* \param impl_t = virtual_tag
|
||||||
|
*/
|
||||||
|
template<>
|
||||||
|
class i2c_i <virtual_tag> {
|
||||||
|
public:
|
||||||
|
using type = i2c_i <virtual_tag>; //!< Export type as identity meta-function
|
||||||
|
|
||||||
|
//! I2C transmit/receive sequence
|
||||||
|
enum class Sequence {
|
||||||
|
BYTE=0, //!< Only read/write byte [8 clocks]
|
||||||
|
ACK, //!< Only send/receive ack [1 clock]
|
||||||
|
BYTEnACK //!< Read/Write byte and ack [9 clocks]
|
||||||
|
};
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name Object lifetime
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
protected:
|
||||||
|
i2c_i () = default; //!< Allow constructor from derived only
|
||||||
|
i2c_i (const type&) = delete; //!< No copies
|
||||||
|
type& operator= (const type&) = delete;
|
||||||
|
public:
|
||||||
|
virtual ~i2c_i () = default; //!< Virtual default destructor
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name Implementation requirements
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
private:
|
||||||
|
virtual uint32_t _frequency () const = 0; //!< \return clock frequency of the bus [Hz]
|
||||||
|
virtual void _frequency (uint32_t) = 0; //!< \brief set clock frequency of the bus [Hz]
|
||||||
|
virtual void _start() = 0; //!< Send start functionality
|
||||||
|
virtual void _stop() = 0; //!< Send stop functionality
|
||||||
|
virtual byte_t _read (bool ack, Sequence seq) = 0; //!< Receive a byte from the i2c bus.
|
||||||
|
virtual bool _write (byte_t byte, Sequence seq) = 0; //!< Transmit a byte to the i2c bus.
|
||||||
|
//!@}
|
||||||
|
/*!
|
||||||
|
* \name Get/Set functions
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
public:
|
||||||
|
uint32_t frequency () const { return _frequency(); } //!< \return clock frequency of the bus [Hz]
|
||||||
|
void frequency (uint32_t f) { _frequency(f); } //!< \brief set clock frequency of the bus [Hz]
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name User functions
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
public:
|
||||||
|
void start () { _start(); }
|
||||||
|
void stop () { _stop(); }
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Receive a byte from the i2c bus.
|
||||||
|
* \param ack Optional ack bit.
|
||||||
|
* \arg 1 ACK the reception
|
||||||
|
* \arg 0 Don't ACK the reception.
|
||||||
|
* \param seq The operation sequence to execute
|
||||||
|
* \arg Sequence::BYTE Receive only the byte, do not send ack clock
|
||||||
|
* \arg Sequence::ACK Send only the ack bit
|
||||||
|
* \arg Sequence::BYTEnACK Receive the byte and send the ack bit
|
||||||
|
* \return The byte received.
|
||||||
|
*/
|
||||||
|
byte_t read (bool ack, Sequence seq =Sequence::BYTEnACK) {
|
||||||
|
return _read (ack, seq);
|
||||||
|
}
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Transmit a byte to the i2c bus.
|
||||||
|
* \param byte The byte to send.
|
||||||
|
* \param seq The operation sequence to execute
|
||||||
|
* \arg Sequence::BYTE Transmit only the byte, do not read ack bit
|
||||||
|
* \arg Sequence::ACK Read only the ack bit
|
||||||
|
* \arg Sequence::BYTEnACK Transmit the byte and read the ack bit
|
||||||
|
* \return Slave's ACK bit
|
||||||
|
* \arg false Slave didn't ACK
|
||||||
|
* \arg true Slave did ACK
|
||||||
|
*/
|
||||||
|
bool write (byte_t byte, Sequence seq =Sequence::BYTEnACK) {
|
||||||
|
return _write (byte, seq);
|
||||||
|
}
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
};
|
||||||
|
|
||||||
|
#if defined _utl_have_concepts
|
||||||
|
/*!
|
||||||
|
* i2c interface concept
|
||||||
|
*/
|
||||||
|
template <typename T>
|
||||||
|
concept bool i2c_c = requires (T t, const T ct, typename T::Sequence s) {
|
||||||
|
// Object type
|
||||||
|
requires not_<std::is_copy_constructible<T>::value>::value;
|
||||||
|
requires not_<std::is_copy_assignable<T>::value>::value;
|
||||||
|
// Methods
|
||||||
|
{ct.frequency()} -> uint32_t;
|
||||||
|
{t.frequency(0)} -> void;
|
||||||
|
{t.start()} -> void;
|
||||||
|
{t.stop()} -> void;
|
||||||
|
{t.read (1, s)} -> byte_t;
|
||||||
|
{t.write(0, s)} -> bool;
|
||||||
|
};
|
||||||
|
#else
|
||||||
|
namespace i2c_t_cnpt {
|
||||||
|
using std::declval;
|
||||||
|
|
||||||
|
template <class _Tp> using try_cfreq_t = decltype (declval<const _Tp>().frequency());
|
||||||
|
template <class _Tp> using try_freq_t = decltype (declval<_Tp>().frequency(declval<uint32_t>()));
|
||||||
|
template <class _Tp> using try_start_t = decltype (declval<_Tp>().start());
|
||||||
|
template <class _Tp> using try_stop_t = decltype (declval<_Tp>().stop());
|
||||||
|
template <class _Tp> using try_read_t
|
||||||
|
= decltype (declval<_Tp>().read (declval<bool>(), declval<typename _Tp::Sequence>()));
|
||||||
|
template <class _Tp> using try_write_t
|
||||||
|
= decltype (declval<_Tp>().write (declval<byte_t>(), declval<typename _Tp::Sequence>()));
|
||||||
|
|
||||||
|
//! Primary template to catch any non I2C interface types
|
||||||
|
template <typename _Tp, typename =void>
|
||||||
|
struct is_i2c_ : false_ { };
|
||||||
|
|
||||||
|
//! template to catch a proper I2C interface type
|
||||||
|
template <typename _Tp>
|
||||||
|
struct is_i2c_ <_Tp,
|
||||||
|
void_t <
|
||||||
|
typename _Tp::Sequence,
|
||||||
|
use_if_same_t <uint32_t,try_cfreq_t <_Tp>>,
|
||||||
|
use_if_same_t <void, try_freq_t <_Tp>>,
|
||||||
|
use_if_same_t <void, try_start_t <_Tp>>,
|
||||||
|
use_if_same_t <void, try_stop_t <_Tp>>,
|
||||||
|
use_if_same_t <byte_t, try_read_t <_Tp>>,
|
||||||
|
use_if_same_t <bool, try_write_t <_Tp>>
|
||||||
|
> //!^ SFINAE may apply inside if_same_t<> also
|
||||||
|
> : true_ { };
|
||||||
|
}
|
||||||
|
/*!
|
||||||
|
* Value meta-programming function alias for I2C interface checking
|
||||||
|
* \param _Tp Type to check
|
||||||
|
* \return True if _Tp is a i2c interface
|
||||||
|
*/
|
||||||
|
template <typename _Tp>
|
||||||
|
constexpr bool i2c_c = i2c_t_cnpt::is_i2c_<_Tp>::value;
|
||||||
|
#endif
|
||||||
|
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
} // namespace utl
|
||||||
|
|
||||||
|
#endif // _utl_com_i2c_h__
|
||||||
407
include/utl/com/i2c_bb.h
Normal file
407
include/utl/com/i2c_bb.h
Normal file
@ -0,0 +1,407 @@
|
|||||||
|
/*!
|
||||||
|
* \file utl/com/i2c_bb.h
|
||||||
|
* \brief A bit banking implementation of i2c bus inherited from
|
||||||
|
* i2c_i base class.
|
||||||
|
*
|
||||||
|
* Copyright (C) 2018 Christos Choutouridis
|
||||||
|
*
|
||||||
|
* This program 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 3
|
||||||
|
* of the License, or (at your option) any later version.
|
||||||
|
*
|
||||||
|
* This program 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 program. If not, see <http://www.gnu.org/licenses/>.
|
||||||
|
*
|
||||||
|
*/
|
||||||
|
#ifndef __utl_com_i2c_bb_h__
|
||||||
|
#define __utl_com_i2c_bb_h__
|
||||||
|
|
||||||
|
#include <utl/impl/impl.h>
|
||||||
|
#include <utl/helper/crtp.h>
|
||||||
|
#include <utl/com/i2c.h>
|
||||||
|
|
||||||
|
|
||||||
|
namespace utl {
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \ingroup Communication
|
||||||
|
* \brief A bit banking implementation of i2c bus
|
||||||
|
* inherited from \ref i2c_i base class.
|
||||||
|
* \sa i2c_i
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* I2C bit banking interface template class providing
|
||||||
|
* an I2C using bit banking using CRTP.
|
||||||
|
* \param impl_t The CRTP type (the derived/implementation class typename).
|
||||||
|
*/
|
||||||
|
template <typename impl_t>
|
||||||
|
class i2c_bb_i : public i2c_i<i2c_bb_i<impl_t>> {
|
||||||
|
_CRTP_IMPL(impl_t);
|
||||||
|
friend i2c_i<i2c_bb_i<impl_t>>;
|
||||||
|
|
||||||
|
public:
|
||||||
|
using type = i2c_bb_i<impl_t>; //!< Export type as identity meta-function
|
||||||
|
using Sequence = typename i2c_i<type>::Sequence;
|
||||||
|
//! SDA pin direction enumerator
|
||||||
|
enum class SDAMode {
|
||||||
|
INPUT =0,
|
||||||
|
OUTPUT
|
||||||
|
};
|
||||||
|
/*!
|
||||||
|
* \name Object lifetime
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
protected:
|
||||||
|
//! \brief A default destructor, allow destructor from derived only
|
||||||
|
~i2c_bb_i () noexcept = default;
|
||||||
|
//! \brief A default constructor
|
||||||
|
i2c_bb_i (uint32_t frequency =100000) noexcept
|
||||||
|
: usec_ {1000000/(2*frequency)} { }
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name Implementation requirements
|
||||||
|
* \note
|
||||||
|
* In order for the implementation to have the following as private members
|
||||||
|
* it also need to declare this class as friend
|
||||||
|
* bool SDA (SDAMode mode, bool st);
|
||||||
|
* void SCL (uint8_t st);
|
||||||
|
* void delay (uint32_t usec);
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
private:
|
||||||
|
/*!
|
||||||
|
* Implementers's sda pin function
|
||||||
|
* \param st In SDA_OUTPUT mode, selects the pin output state
|
||||||
|
* \return In SDA_INPUT mode return the pin input state
|
||||||
|
*/
|
||||||
|
bool SDA (SDAMode mode, bool st) { return impl().SDA (mode, st); }
|
||||||
|
void SCL (uint8_t st) { impl().SCL (st); } //!< Implementers's scl pin function
|
||||||
|
void delay (uint32_t usec) { impl().delay(usec); } //!< Implementers's usec delay function
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name Implementation of base requirements
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
private:
|
||||||
|
uint32_t _frequency () const { return 1000000/(2*usec_); }
|
||||||
|
void _frequency (uint32_t f) { usec_ = 1000000/(2*f); }
|
||||||
|
|
||||||
|
void _start (); //!< Send start functionality
|
||||||
|
void _stop (); //!< Send stop functionality
|
||||||
|
byte_t _read (bool ack, Sequence seq);
|
||||||
|
bool _write (byte_t byte, Sequence seq);
|
||||||
|
uint32_t usec_; //!< half period of I2C nus
|
||||||
|
//!@}
|
||||||
|
};
|
||||||
|
|
||||||
|
/*
|
||||||
|
* ============= User functions ================
|
||||||
|
*/
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Send a START bit to the bus
|
||||||
|
* \return none
|
||||||
|
*/
|
||||||
|
template <typename impl_t>
|
||||||
|
void i2c_bb_i<impl_t>::_start (void) {
|
||||||
|
//Initially set pins
|
||||||
|
SDA (SDAMode::OUTPUT, 1);
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
SDA (SDAMode::OUTPUT, 0);
|
||||||
|
delay (usec_);
|
||||||
|
SCL (0); //Clear Clock
|
||||||
|
}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Send a START bit to the bus
|
||||||
|
* \return none
|
||||||
|
*/
|
||||||
|
template <typename impl_t>
|
||||||
|
void i2c_bb_i<impl_t>::_stop (void) {
|
||||||
|
//Stop bit Operation
|
||||||
|
SDA (SDAMode::OUTPUT, 0);
|
||||||
|
SCL (0);
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
SDA (SDAMode::OUTPUT, 1);
|
||||||
|
delay (usec_);
|
||||||
|
}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Receive a byte from the i2c bus.
|
||||||
|
* \param ack Optional ack bit.
|
||||||
|
* \arg 1 ACK the reception
|
||||||
|
* \arg 0 Don't ACK the reception.
|
||||||
|
* \param seq The operation sequence to execute
|
||||||
|
* \arg Sequence::BYTE Receive only the byte, do not send ack clock
|
||||||
|
* \arg Sequence::ACK Send only the ack bit
|
||||||
|
* \arg Sequence::BYTEnACK Receive the byte and send the ack bit
|
||||||
|
* \return The byte received.
|
||||||
|
*/
|
||||||
|
template <typename impl_t>
|
||||||
|
byte_t i2c_bb_i<impl_t>::_read (bool ack, Sequence seq) {
|
||||||
|
byte_t byte {0};
|
||||||
|
//Initial conditions
|
||||||
|
SCL (0);
|
||||||
|
SDA (SDAMode::INPUT, 0);
|
||||||
|
|
||||||
|
if (seq == Sequence::BYTE || seq == Sequence::BYTEnACK) {
|
||||||
|
// read 8 data bits
|
||||||
|
for (int i=8 ; i!=0 ; --i) {
|
||||||
|
byte <<= 1;
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
byte |= SDA (SDAMode::INPUT, 0);
|
||||||
|
SCL (0);
|
||||||
|
delay (usec_);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
if (seq == Sequence::ACK || seq == Sequence::BYTEnACK) {
|
||||||
|
SDA (SDAMode::OUTPUT, !ack); //Send (or not) ACK bit
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
SCL (0); // Keep the bus busy
|
||||||
|
SDA (SDAMode::OUTPUT, 0);
|
||||||
|
}
|
||||||
|
return byte;
|
||||||
|
}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Transmit a byte to the i2c bus.
|
||||||
|
* \param byte The byte to send.
|
||||||
|
* \param seq The operation sequence to execute
|
||||||
|
* \arg Sequence::BYTE Transmit only the byte, do not read ack bit
|
||||||
|
* \arg Sequence::ACK Read only the ack bit
|
||||||
|
* \arg Sequence::BYTEnACK Transmit the byte and read the ack bit
|
||||||
|
* \return Slave's ACK bit
|
||||||
|
* \arg false Slave didn't ACK
|
||||||
|
* \arg true Slave did ACK
|
||||||
|
*/
|
||||||
|
template <typename impl_t>
|
||||||
|
bool i2c_bb_i<impl_t>::_write (byte_t byte, Sequence seq) {
|
||||||
|
bool ack {false};
|
||||||
|
//Initial conditions
|
||||||
|
SCL (0);
|
||||||
|
SDA (SDAMode::OUTPUT, 0);
|
||||||
|
|
||||||
|
if (seq == Sequence::BYTE || seq == Sequence::BYTEnACK) {
|
||||||
|
//Send 8 bit data
|
||||||
|
for (int i=8 ; i!=0 ; --i) {
|
||||||
|
//Send MSB
|
||||||
|
SDA (SDAMode::OUTPUT, byte & 0x80);
|
||||||
|
byte <<= 1;
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
SCL (0);
|
||||||
|
delay (usec_);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
if (seq == Sequence::ACK || seq == Sequence::BYTEnACK) {
|
||||||
|
// Get ACK
|
||||||
|
SDA (SDAMode::INPUT, 0);
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
ack = !SDA (SDAMode::INPUT, 0);
|
||||||
|
SCL (0); // Keep the bus busy
|
||||||
|
delay (usec_);
|
||||||
|
SDA (SDAMode::OUTPUT, 0);
|
||||||
|
}
|
||||||
|
return ack;
|
||||||
|
}
|
||||||
|
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* A virtual base class interface specialization.
|
||||||
|
* Using the private virtual interface we provide the interface from
|
||||||
|
* i2c_i<virtual_tag>
|
||||||
|
* \param impl_t = virtual_tag
|
||||||
|
*/
|
||||||
|
template<>
|
||||||
|
class i2c_bb_i<virtual_tag> : public i2c_i<virtual_tag> {
|
||||||
|
public:
|
||||||
|
using type = i2c_bb_i<virtual_tag>; //!< Export type as identity meta-function
|
||||||
|
using Sequence = typename i2c_i<virtual_tag>::Sequence;
|
||||||
|
//! SDA pin direction enumerator
|
||||||
|
enum class SDAMode {
|
||||||
|
INPUT =0,
|
||||||
|
OUTPUT
|
||||||
|
};
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name Object lifetime
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
protected:
|
||||||
|
//! \brief Constructor
|
||||||
|
i2c_bb_i (uint32_t frequency =100000) noexcept
|
||||||
|
: usec_ {1000000/(2*frequency)} { }
|
||||||
|
//! \brief Virtual destructor
|
||||||
|
virtual ~i2c_bb_i () noexcept = default;
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name Implementation requirements
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
private:
|
||||||
|
/*!
|
||||||
|
* Implementers's sda pin function
|
||||||
|
* \param st In SDA_OUTPUT mode, selects the pin output state
|
||||||
|
* \return In SDA_INPUT mode return the pin input state
|
||||||
|
*/
|
||||||
|
virtual bool SDA (SDAMode mode, bool st) =0;
|
||||||
|
virtual void SCL (bool st) =0; //!< Implementers's scl pin function
|
||||||
|
virtual void delay (uint32_t usec) =0; //!< Implementers's usec delay function
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \name Implementation of base requirements
|
||||||
|
*/
|
||||||
|
//!@{
|
||||||
|
private:
|
||||||
|
uint32_t _frequency () const final { return 1000000/(2*usec_); }
|
||||||
|
void _frequency (uint32_t f) final { usec_ = 1000000/(2*f); }
|
||||||
|
|
||||||
|
void _start () final;
|
||||||
|
void _stop () final;
|
||||||
|
byte_t _read (bool ack, Sequence seq) final;
|
||||||
|
bool _write (byte_t byte, Sequence seq) final;
|
||||||
|
//!< half period of I2C bus
|
||||||
|
uint32_t usec_;
|
||||||
|
//!@}
|
||||||
|
};
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Send a START bit to the bus
|
||||||
|
* \return none
|
||||||
|
*/
|
||||||
|
void i2c_bb_i<virtual_tag>::_start (void) {
|
||||||
|
//Initially set pins
|
||||||
|
SDA (SDAMode::OUTPUT, 1);
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
SDA (SDAMode::OUTPUT, 0);
|
||||||
|
delay (usec_);
|
||||||
|
SCL (0); //Clear Clock
|
||||||
|
}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Send a START bit to the bus
|
||||||
|
* \return none
|
||||||
|
*/
|
||||||
|
void i2c_bb_i<virtual_tag>::_stop (void) {
|
||||||
|
//Stop bit Operation
|
||||||
|
SDA (SDAMode::OUTPUT, 0);
|
||||||
|
SCL (0);
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
SDA (SDAMode::OUTPUT, 1);
|
||||||
|
delay (usec_);
|
||||||
|
}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Receive a byte from the i2c bus.
|
||||||
|
* \param ack Optional ack bit.
|
||||||
|
* \arg 1 ACK the reception
|
||||||
|
* \arg 0 Don't ACK the reception.
|
||||||
|
* \param seq The operation sequence to execute
|
||||||
|
* \arg Sequence::BYTE Receive only the byte, do not send ack clock
|
||||||
|
* \arg Sequence::ACK Send only the ack bit
|
||||||
|
* \arg Sequence::BYTEnACK Receive the byte and send the ack bit
|
||||||
|
* \return The byte received.
|
||||||
|
*/
|
||||||
|
byte_t i2c_bb_i<virtual_tag>::_read (bool ack, Sequence seq) {
|
||||||
|
byte_t byte {0};
|
||||||
|
//Initial conditions
|
||||||
|
SCL (0);
|
||||||
|
SDA (SDAMode::INPUT, 0);
|
||||||
|
|
||||||
|
if (seq == Sequence::BYTE || seq == Sequence::BYTEnACK) {
|
||||||
|
// read 8 data bits
|
||||||
|
for (int i=8 ; i!=0 ; --i) {
|
||||||
|
byte <<= 1;
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
byte |= SDA (SDAMode::INPUT, 0);
|
||||||
|
SCL (0);
|
||||||
|
delay (usec_);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
if (seq == Sequence::ACK || seq == Sequence::BYTEnACK) {
|
||||||
|
SDA (SDAMode::OUTPUT, !ack); //Send (or not) ACK bit
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
SCL (0); // Keep the bus busy
|
||||||
|
SDA (SDAMode::OUTPUT, 0);
|
||||||
|
}
|
||||||
|
return byte;
|
||||||
|
}
|
||||||
|
|
||||||
|
/*!
|
||||||
|
* \brief
|
||||||
|
* Transmit a byte to the i2c bus.
|
||||||
|
* \param byte The byte to send.
|
||||||
|
* \param seq The operation sequence to execute
|
||||||
|
* \arg Sequence::BYTE Transmit only the byte, do not read ack bit
|
||||||
|
* \arg Sequence::ACK Read only the ack bit
|
||||||
|
* \arg Sequence::BYTEnACK Transmit the byte and read the ack bit
|
||||||
|
* \return Slave's ACK bit
|
||||||
|
* \arg false Slave didn't ACK
|
||||||
|
* \arg true Slave did ACK
|
||||||
|
*/
|
||||||
|
bool i2c_bb_i<virtual_tag>::_write (byte_t byte, Sequence seq) {
|
||||||
|
bool ack {false};
|
||||||
|
//Initial conditions
|
||||||
|
SCL (0);
|
||||||
|
SDA (SDAMode::OUTPUT, 0);
|
||||||
|
|
||||||
|
if (seq == Sequence::BYTE || seq == Sequence::BYTEnACK) {
|
||||||
|
//Send 8 bit data
|
||||||
|
for (int i=8 ; i!=0 ; --i) {
|
||||||
|
//Send MSB
|
||||||
|
SDA (SDAMode::OUTPUT, byte & 0x80);
|
||||||
|
byte <<= 1;
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
SCL (0);
|
||||||
|
delay (usec_);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
if (seq == Sequence::ACK || seq == Sequence::BYTEnACK) {
|
||||||
|
// Get ACK
|
||||||
|
SDA (SDAMode::INPUT, 0);
|
||||||
|
SCL (1);
|
||||||
|
delay (usec_);
|
||||||
|
ack = !SDA (SDAMode::INPUT, 0);
|
||||||
|
SCL (0); // Keep the bus busy
|
||||||
|
delay (usec_);
|
||||||
|
SDA (SDAMode::OUTPUT, 0);
|
||||||
|
}
|
||||||
|
return ack;
|
||||||
|
}
|
||||||
|
//!@}
|
||||||
|
|
||||||
|
} // namspace utl
|
||||||
|
|
||||||
|
|
||||||
|
#endif // #ifndef __utl_com_i2c_bb_h__
|
||||||
|
|
||||||
Loading…
x
Reference in New Issue
Block a user