HostPort Class Reference

A class for communication with PC via USB/serial. More...

#include <HostPort.h>

Public Member Functions
	HostPort (Stream *serial, uint32_t header, uint32_t terminator)
	Contructor with header and terminator.
	HostPort (Stream *serial, uint32_t header)
	Contructor with header only.
	HostPort (Stream *serial)
	Contructor with no header and terminator.
boolean	attachRx (uint8_t *pointer, size_t size)
	Attach object for receiving.
boolean	attachTx (uint8_t *pointer, size_t size)
	Attach object for tranmission.
boolean	write ()
	Write to serial.
boolean	read ()
	Read from serial.

Static Public Attributes
static constexpr uint32_t	NULL_HEADER = 0x00000000
	Null header.
static constexpr uint32_t	NULL_TERMINATOR = 0x00000000
	Null terminator.
static constexpr uint32_t	DEF_HEADER = 0xFF812345
	4-bytes default header of data packet.
static constexpr uint32_t	DEF_TERMINATOR = 0xFF8CABDE
	4-bytes terminator of data packet.

Private Member Functions
void	init (void)
	Initialize the host port.
void	copyrx (void)
	Copy receive buffer into receive objects.

Private Attributes
uint8_t	_rx_buf [BUF_SIZE] = { 0 }
	Receive buffer.
uint8_t	_tx_buf [BUF_SIZE] = { 0 }
	Transmit buffer.
uint32_t	_header = NULL_HEADER
	4-bytes header.
uint32_t	_terminator = NULL_TERMINATOR
	4-bytes terminator.
uint8_t *	_ptr_rx [MAX_OBJS] = { nullptr }
	Pointers to receive objects.
uint8_t *	_ptr_tx [MAX_OBJS] = { nullptr }
	Pointers to transmit objects.
size_t	_size_rx [MAX_OBJS] = { 0 }
	Sizes of receive objects.
size_t	_size_tx [MAX_OBJS] = { 0 }
	Sizes of transmit objects.
size_t	_totSize_rx = 0
	Total size of receive objects.
size_t	_totSize_tx = 0
	Total size of transmit objects.
uint8_t	_numObj_rx = 0
	Total number of receive objects.
uint8_t	_numObj_tx = 0
	Total number of transmit objects.
Stream *	_serial = nullptr
	Pointer to Stream object.

Static Private Attributes
static constexpr size_t	BUF_SIZE = 256
	Buffer size.
static constexpr size_t	MAX_OBJS = 4
	Maximum objects.
static constexpr uint32_t	MASK = 0x000000FF
	A mask for parsing stuff.
static constexpr uint32_t	TIMEOUT_HOSTPORT = 500
	Timeout for the reading (us).

Detailed Description

A class for communication with PC via USB/serial.

The class manages the communication between a microcontroller and a host PC via USB/serial. The trasmitted or received data packets consists of:

• A possible 4-bytes header (disabled with HostPort::NULL_HEADER).
• The data bytes, for a maximum of HostPort::BUF_SIZE bytes with HostPort::MAX_OBJS objects.
• A possible 4-bytes terminator (disabled with HostPort::NULL_TERMINATOR).

The HostPort object is created using

HostPort hostPort(&Serial, HostPort::NULL_HEADER, HostPort::NULL_TERMINATOR); //with neither header nor terminator
HostPort hostPort(&Serial); //with neither header nor terminator
HostPort hostPort(&Serial, header, HostPort::NULL_TERMINATOR); //with header only
HostPort hostPort(&Serial, header); //with header only
HostPort hostPort(&Serial, HostPort::NULL_HEADER, terminator); //with terminator only
HostPort hostPort(&Serial, header, terminator); //with header and terminator

Objects can be attached to the trasmit buffer using (for a maximum of HostPort::MAX_OBJS objects)

hostPort.attachTx((uint8_t*) &object1, sizeof(object1));
hostPort.attachTx((uint8_t*) &object2, sizeof(object2));

Objects can be attached to the receive buffer using (for a maximum of HostPort::MAX_OBJS objects)

hostPort.attachRx((uint8_t*) &object3, sizeof(object3));
hostPort.attachRx((uint8_t*) &object4, sizeof(object4));

Finally trasfering and receiving is performed using

hostPort.write();
hostPort.read();

Author

Stefano Lovato

Date

2022

Constructor & Destructor Documentation

HostPort() [1/3]

HostPort::HostPort	(	Stream *	serial,
		uint32_t	header,
		uint32_t	terminator )

Contructor with header and terminator.

The constructor with user-defined header and terminator.

Parameters

serial	The pointer to the Stream object used for the serial.
header	The 4-bytes header of the data packet. Use HostPort::NULL_HEADER for no header.
terminator	The 4-bytes terminator of the data packet. Use HostPort::NULL_TERMINATOR for no header.

HostPort() [2/3]

HostPort::HostPort	(	Stream *	serial,
		uint32_t	header )

Contructor with header only.

The constructor with user-defined header and no terminator.

Parameters

serial	The pointer to the Stream object used for the serial.
header	The 4-bytes header of the data packet. Use HostPort::NULL_HEADER for no header.

HostPort() [3/3]

HostPort::HostPort

(

Stream *

serial

)

Contructor with no header and terminator.

The constructor with no header and terminator.

Parameters

serial

The pointer to the Stream object used for the serial.

Member Function Documentation

attachRx()

boolean HostPort::attachRx	(	uint8_t *	pointer,
		size_t	size )

Attach object for receiving.

The function attaches an object to the receive buffer. A number of MAX_OBJS objects can be attached, for a total of maximum BUF_SIZE bytes.

Parameters

pointer	The pointer to the object to attach. Cast to uint8_t is required.
size	Thesize to the object to attach.

Returns

True if success, false if the buffer size or the number of objects exceeds BUF_SIZE or MAX_OBJS.

See also

MAX_OBJS BUF_SIZE

attachTx()

boolean HostPort::attachTx	(	uint8_t *	pointer,
		size_t	size )

Attach object for tranmission.

The function attaches an object to the trasmit buffer. A number of MAX_OBJS objects can be attached, for a total of maximum BUF_SIZE bytes.

Parameters

pointer	The pointer to the object to attach. Cast to uint8_t is required.
size	Thesize to the object to attach.

Returns

True if success, false if the buffer size or the number of objects exceeds BUF_SIZE or MAX_OBJS.

See also

MAX_OBJS BUF_SIZE

copyrx()

void HostPort::copyrx ( void )

private

Copy receive buffer into receive objects.

The function copies the receive buffer into the receive attached objects when the read is successful.

init()

void HostPort::init ( void )

private

Initialize the host port.

The function performs the inizializaton of the host port.

read()

boolean HostPort::read

(

)

Read from serial.

The function reads a data packet from the serial and saves it in the attached receive objects.

Returns

True if success.

Attention

The serial object must be started by the user before reading.

write()

boolean HostPort::write

(

)

Write to serial.

The function writes the attached transmit objects to the serial.

Returns

True if success.

Attention

The serial object must be started by the user before writing.

Member Data Documentation

_header

uint32_t HostPort::_header = NULL_HEADER

private

4-bytes header.

The 4-bytes header is null when equal to NULL_HEADER.

See also

NULL_HEADER

_numObj_rx

uint8_t HostPort::_numObj_rx = 0

private

Total number of receive objects.

The total number of receive objects must be lower than MAX_OBJS.

See also

MAX_OBJS

_numObj_tx

uint8_t HostPort::_numObj_tx = 0

private

Total number of transmit objects.

The total number of transmit objects must be lower than MAX_OBJS.

See also

MAX_OBJS

_ptr_rx

uint8_t* HostPort::_ptr_rx[MAX_OBJS] = { nullptr }

private

Pointers to receive objects.

The arrays of pointers to the receive attached objects. It has size MAX_OBJS.

See also

MAX_OBJS attachRx

_ptr_tx

uint8_t* HostPort::_ptr_tx[MAX_OBJS] = { nullptr }

private

Pointers to transmit objects.

The arrays of pointers to the transmit attached objects. It has size MAX_OBJS.

See also

MAX_OBJS attachTx

_rx_buf

uint8_t HostPort::_rx_buf[BUF_SIZE] = { 0 }

private

Receive buffer.

The receive buffer has size BUF_SIZE.

See also

BUF_SIZE attachRx

_serial

Stream* HostPort::_serial = nullptr

private

Pointer to Stream object.

The pointer to a Stream object representing the serial.

Attention

The serial must be started before using this class.

_size_rx

size_t HostPort::_size_rx[MAX_OBJS] = { 0 }

private

Sizes of receive objects.

The arrays of sizes of the receive attached objects. It has size MAX_OBJS.

See also

MAX_OBJS attachRx

_size_tx

size_t HostPort::_size_tx[MAX_OBJS] = { 0 }

private

Sizes of transmit objects.

The arrays of sizes of the transmit attached objects. It has size MAX_OBJS.

See also

MAX_OBJS attachTx

_terminator

uint32_t HostPort::_terminator = NULL_TERMINATOR

private

4-bytes terminator.

The 4-bytes terminator is null when equal to NULL_TERMINATOR.

See also

NULL_TERMINATOR

_totSize_rx

size_t HostPort::_totSize_rx = 0

private

Total size of receive objects.

The total size of receive objects must be lower than BUF_SIZE.

See also

BUF_SIZE

_totSize_tx

size_t HostPort::_totSize_tx = 0

private

Total size of transmit objects.

The total size of transmit objects must be lower than BUF_SIZE.

See also

BUF_SIZE

_tx_buf

uint8_t HostPort::_tx_buf[BUF_SIZE] = { 0 }

private

Transmit buffer.

The transmit buffer has size BUF_SIZE.

See also

BUF_SIZE attachTx

BUF_SIZE

size_t HostPort::BUF_SIZE = 256

staticconstexprprivate

Buffer size.

The size of the transmit and receive buffers.

DEF_HEADER

uint32_t HostPort::DEF_HEADER = 0xFF812345

staticconstexpr

4-bytes default header of data packet.

This value is an ovf in float, and thus it is safe.

DEF_TERMINATOR

uint32_t HostPort::DEF_TERMINATOR = 0xFF8CABDE

staticconstexpr

4-bytes terminator of data packet.

This value is an ovf in float.

MASK

uint32_t HostPort::MASK = 0x000000FF

staticconstexprprivate

A mask for parsing stuff.

MAX_OBJS

size_t HostPort::MAX_OBJS = 4

staticconstexprprivate

Maximum objects.

The number of maximum attached objects to the transmit and receive buffers-

NULL_HEADER

uint32_t HostPort::NULL_HEADER = 0x00000000

staticconstexpr

Null header.

The value used for no header.

NULL_TERMINATOR

uint32_t HostPort::NULL_TERMINATOR = 0x00000000

staticconstexpr

Null terminator.

The value used for no terminator.

TIMEOUT_HOSTPORT

uint32_t HostPort::TIMEOUT_HOSTPORT = 500

staticconstexprprivate

Timeout for the reading (us).