Functions
int8_t	frame_sys_message (uint8_t *dest, Magics::SYS sys_type)

int8_t	frame_cmd_type_message (uint8_t *dest, const uint8_t type)

int8_t	frame_cmd_modes_message (uint8_t *dest, const uint8_t modes, const uint8_t modes_available)

int8_t	frame_cmd_speed_message (uint8_t *dest, const uint32_t speed)

int8_t	frame_cmd_select_message (uint8_t *dest, const uint8_t mode)

int8_t	frame_cmd_write_message (uint8_t dest, const uint8_t data, const uint8_t len)

int8_t	frame_info_message_name (uint8_t dest, const uint8_t mode, const char name)

int8_t	frame_info_message_span (uint8_t *dest, const uint8_t mode, Magics::INFO_SPAN span_type, const float lower, const float upper)

int8_t	frame_info_message_symbol (uint8_t dest, const uint8_t mode, const char symbol)

int8_t	frame_info_message_format (uint8_t *dest, const uint8_t mode, const uint8_t elems, Magics::INFO_DTYPE data_type, const uint8_t width, const uint8_t decimals)

int8_t	frame_data_message (uint8_t dest, const uint8_t mode, const uint8_t data, const uint8_t len)

uint8_t	checksum (const uint8_t *buf, const uint8_t len)

uint8_t	insert_padding (uint8_t *dest, uint8_t len)

constexpr uint8_t	log2 (uint8_t val)

constexpr uint8_t	length_code (uint8_t len)

Variables
constexpr uint8_t	BUFFER_MIN { 0x23 }
	Minimum size of the buffer (in bytes) that the user has to provide to each of the framing functions, to avoid any chance of a buffer overflow. More...

constexpr uint8_t	PAYLOAD_SENSOR_TO_EV3_MAX { 0x20 }
	Maximum size of any payload sent in the EV3 UART sensor protocol, in bytes, to the EV3. More...

constexpr uint8_t	PAYLOAD_EV3_TO_SENSOR_MAX { 0x18 }
	Maximum size of any payload sent in the EV3 UART sensor protocol, in bytes, from the EV3 to the sensor. More...

constexpr uint8_t	PAYLOAD_MIN { 0x01 }
	Minimum size of any payload sent in the EV3 UART sensor protocol, regardless of direction, in bytes. More...

constexpr uint8_t	SYMBOL_MAX { 0x08 }
	Maximum length of the string representation (ASCII) of any symbol referencing a the SI unit used to represent the data output from a sensor, in a particular mode. More...

Function Documentation

◆ checksum()

uint8_t EV3UartGenerator::Framing::checksum	(	const uint8_t *	buf,
		const uint8_t	len
	)

Calculates the checksum for an EV3 data message.

Parameters

buf	source buffer
len	length of data message in the source buffer

Returns: checksum of len bytes of data in the source buffer

Definition at line 203 of file framing.cpp.

Referenced by frame_cmd_modes_message(), frame_cmd_select_message(), frame_cmd_speed_message(), frame_cmd_type_message(), frame_cmd_write_message(), frame_data_message(), frame_info_message_format(), frame_info_message_name(), frame_info_message_span(), and frame_info_message_symbol().

◆ frame_cmd_modes_message()

int8_t EV3UartGenerator::Framing::frame_cmd_modes_message	(	uint8_t *	dest,
		const uint8_t	modes,
		const uint8_t	modes_visible
	)

Frame an EV3 command message, containing sensor mode information.

For sensor mode set upper bounds, an upper bound of n implies that modes n - 1, n - 2, n - 3 ... 0 are contained in the set of modes bounded by the upper bound.

Parameters

dest	destination buffer
modes	upper bound of sensor modes in sensor mode set [0, 7]
modes_visible	upper bound of sensor modes in the set of sensor modes visible [0, 7] to the user

Returns: length of framed message (written to the buffer), if positive.

Return values

-1	on error (not used)

Definition at line 33 of file framing.cpp.

References checksum(), EV3UartGenerator::Magics::CMD_BASE, length_code(), and EV3UartGenerator::Magics::MODES.

Referenced by main().

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◆ frame_cmd_select_message()

int8_t EV3UartGenerator::Framing::frame_cmd_select_message	(	uint8_t *	dest,
		const uint8_t	mode
	)

Frame an EV3 command message, selecting a particular mode of the sensor

Parameters

dest	destination buffer
mode	mode to select [0, 7]

Returns: length of framed message (written to the buffer), if positive.

Return values

-1	on error (not used)

Definition at line 58 of file framing.cpp.

References checksum(), EV3UartGenerator::Magics::CMD_BASE, length_code(), and EV3UartGenerator::Magics::SELECT.

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◆ frame_cmd_speed_message()

int8_t EV3UartGenerator::Framing::frame_cmd_speed_message	(	uint8_t *	dest,
		const uint32_t	speed
	)

Frame an EV3 commmand message, containing UART baudrate information.

Parameters

dest	destination buffer
speed	baudrate requested / maximum baudrate supported by the device.

Returns: length of framed message (written to the buffer), if positive.

Return values

-1	on error (not used)

Definition at line 45 of file framing.cpp.

References checksum(), EV3UartGenerator::Magics::CMD_BASE, EV3UartGenerator::SimpleEndian::htole32(), length_code(), and EV3UartGenerator::Magics::SPEED.

Referenced by main().

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◆ frame_cmd_type_message()

int8_t EV3UartGenerator::Framing::frame_cmd_type_message	(	uint8_t *	dest,
		const uint8_t	type
	)

Frame an EV3 command message, containing sensor type information

Parameters

dest	destination buffer
type	sensor type index [0, 255]

Returns: length of framed message (written to the buffer), if positive.

Return values

-1	on error (unused)

Definition at line 23 of file framing.cpp.

References checksum(), EV3UartGenerator::Magics::CMD_BASE, length_code(), and EV3UartGenerator::Magics::TYPE.

Referenced by main().

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◆ frame_cmd_write_message()

int8_t EV3UartGenerator::Framing::frame_cmd_write_message	(	uint8_t *	dest,
		const uint8_t *	data,
		const uint8_t	len
	)

Frame an EV3 command message, writing arbitrary data to the sensor.

Parameters

dest	destination buffer
data	data to write to the sensor
len	length of array of data to write to the sensor [1, 32]

Returns: length of framed message (written to the buffer), if positive.

Return values

-1	on error (length overrun / underrun)

Definition at line 68 of file framing.cpp.

References checksum(), EV3UartGenerator::Magics::CMD_BASE, insert_padding(), length_code(), PAYLOAD_EV3_TO_SENSOR_MAX, PAYLOAD_MIN, and EV3UartGenerator::Magics::WRITE.

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◆ frame_data_message()

int8_t EV3UartGenerator::Framing::frame_data_message	(	uint8_t *	dest,
		const uint8_t	mode,
		const uint8_t *	data,
		const uint8_t	len
	)

Frame an EV3 data message, containing information from a sensor to be sent to an EV3, for the sensor running in a particular mode

Parameters

dest	destination buffer
mode	mode index [0, 7]
data	data to be sent
len	length of data to be sent [1, 32]

Returns: length of framed message (written to the buffer), if positive.

Return values

-1	on error (length overrun)

Definition at line 184 of file framing.cpp.

References checksum(), EV3UartGenerator::Magics::DATA_BASE, insert_padding(), length_code(), PAYLOAD_MIN, and PAYLOAD_SENSOR_TO_EV3_MAX.

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◆ frame_info_message_format()

int8_t EV3UartGenerator::Framing::frame_info_message_format	(	uint8_t *	dest,
		const uint8_t	mode,
		const uint8_t	elems,
		Magics::INFO_DTYPE	data_type,
		const uint8_t	width,
		const uint8_t	decimals
	)

Frame an EV3 information message, informing the EV3 of the type and number of data elements contained in the data messages coming from the sensor, as well as the number of decimal places and width to use when displaying readings for the sensor, for a particular mode of the sensor.

Parameters

dest destination buffer

mode mode index [0, 7]

elems

number of data elements in a DATA message, limited to:

Data type	Number of data elements
S8	[1, 32]
S16	[1, 16]
Sr32	[1, 8]
F32	[1, 8]

data_type type of data elements

width number of characters (including decimal separator) used to display readings from the sensor [0, 15]

decimals number of characters after the decimal place used to display readings from the sensor [0, 15]

Returns: length of framed message (written to the buffer), if positive.

Return values

-1	on error (not used)

Definition at line 167 of file framing.cpp.

References checksum(), EV3UartGenerator::Magics::INFO_BASE, and length_code().

Referenced by main().

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◆ frame_info_message_name()

int8_t EV3UartGenerator::Framing::frame_info_message_name	(	uint8_t *	dest,
		const uint8_t	mode,
		const char *	name
	)

Frame an EV3 information message, informing the EV3 of the mode name for a particular mode of the sensor.

Parameters

dest	destination buffer
mode	mode index [0, 7]
name	mode name [1 to 32 ASCII byte characters in length]

Returns: length of framed message (written to the buffer), if positive.

Return values

-1	on error (length overrun / underrun / name == nullptr)

Definition at line 87 of file framing.cpp.

References checksum(), EV3UartGenerator::Magics::INFO_BASE, insert_padding(), length_code(), PAYLOAD_MIN, and PAYLOAD_SENSOR_TO_EV3_MAX.

Referenced by main().

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◆ frame_info_message_span()

int8_t EV3UartGenerator::Framing::frame_info_message_span	(	uint8_t *	dest,
		const uint8_t	mode,
		Magics::INFO_SPAN	span_type,
		const float	lower,
		const float	upper
	)

Frame an EV3 information message, informing the EV3 of the span of values returned from this sensor, for different units of readings from the sensor, for a particular mode of the sensor

This message is optional, and may be omitted during the initialization process, where mode information is sent from the sensor to the EV3.

Parameters

dest	destination buffer
mode	mode index [0, 7]
span_type	type of span for which information is to be sent for
lower	lower bound of the span
upper	upper bound of the span

Returns: length of framed message (written to the buffer), if positive.

Return values

-1	on error (unused)

Warning: this function MUST NOT be used in environments where the representation of single precision floating point numbers does not follow the IEEE standard.

Definition at line 109 of file framing.cpp.

References checksum(), EV3UartGenerator::SimpleEndian::htole32(), EV3UartGenerator::Magics::INFO_BASE, and length_code().

Referenced by main().

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◆ frame_info_message_symbol()

int8_t EV3UartGenerator::Framing::frame_info_message_symbol	(	uint8_t *	dest,
		const uint8_t	mode,
		const char *	symbol
	)

Frame an EV3 information message, informing the EV3 of the text representation of the symbol (unit) used to represent the SI unit that can be used to quantify readings from the sensor, for readings from the sensor coming from a particular mode index.

Parameters

dest	destination buffer
mode	mode index [0 - 7]
symbol	symbol text representation string [1 to 8 ASCII bytes in length]

Returns: length of framed message (written to the buffer), if positive.

Return values

-1	on error (length overrun / underrun / symbol == nullptr)

Definition at line 142 of file framing.cpp.

References checksum(), EV3UartGenerator::Magics::INFO_BASE, length_code(), PAYLOAD_MIN, and SYMBOL_MAX.

Referenced by main().

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◆ frame_sys_message()

int8_t EV3UartGenerator::Framing::frame_sys_message	(	uint8_t *	dest,
		Magics::SYS	sys_type
	)

Frame an EV3 system message.

Parameters

dest	destination buffer
sys_type	type of the system message

Returns: length of framed message (written to the buffer), if positive.

Return values

-1	on error (unused)

Definition at line 17 of file framing.cpp.

References EV3UartGenerator::Magics::SYS_BASE.

Referenced by main().

◆ insert_padding()

uint8_t EV3UartGenerator::Framing::insert_padding	(	uint8_t *	dest,
		uint8_t	len
	)

Inserts padding bytes at the end of a payload segment, so that the size of the payload segment is a non-negative power of two.

Parameters

dest	address of the byte right after the end of the payload segment
len	length of payload segment [1, 32]

Returns: number of padding bytes written

Definition at line 211 of file framing.cpp.

References log2().

Referenced by frame_cmd_write_message(), frame_data_message(), and frame_info_message_name().

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◆ length_code()

constexpr uint8_t EV3UartGenerator::Framing::length_code ( uint8_t len )

Calculates the value that is to be OR'd into the message type byte to represent the length of the payload in the message.

Parameters

len	length of the payload [1, 32]

Returns: value to be OR'd into the message type byte to represent the length of the payload in the message.

Definition at line 244 of file framing.hpp.

References log2().

Referenced by frame_cmd_modes_message(), frame_cmd_select_message(), frame_cmd_speed_message(), frame_cmd_type_message(), frame_cmd_write_message(), frame_data_message(), frame_info_message_format(), frame_info_message_name(), frame_info_message_span(), and frame_info_message_symbol().

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◆ log2()

constexpr uint8_t EV3UartGenerator::Framing::log2 ( uint8_t val )

Calculates the integer log_2 of a particular unsigned integer value, rounded up.

Parameters

val	value to calculate log_2 for [1, 255]

Returns: result of log_2 of val rounded up to the next biggest integer.

Warning: undefined for val of 0.

Definition at line 231 of file framing.hpp.

Referenced by insert_padding(), and length_code().

Variable Documentation

◆ BUFFER_MIN

constexpr uint8_t EV3UartGenerator::Framing::BUFFER_MIN { 0x23 }

Minimum size of the buffer (in bytes) that the user has to provide to each of the framing functions, to avoid any chance of a buffer overflow.

Definition at line 39 of file framing.hpp.

◆ PAYLOAD_EV3_TO_SENSOR_MAX

constexpr uint8_t EV3UartGenerator::Framing::PAYLOAD_EV3_TO_SENSOR_MAX { 0x18 }

Maximum size of any payload sent in the EV3 UART sensor protocol, in bytes, from the EV3 to the sensor.

Definition at line 41 of file framing.hpp.

Referenced by frame_cmd_write_message().

◆ PAYLOAD_MIN

constexpr uint8_t EV3UartGenerator::Framing::PAYLOAD_MIN { 0x01 }

Minimum size of any payload sent in the EV3 UART sensor protocol, regardless of direction, in bytes.

Definition at line 42 of file framing.hpp.

Referenced by frame_cmd_write_message(), frame_data_message(), frame_info_message_name(), and frame_info_message_symbol().

◆ PAYLOAD_SENSOR_TO_EV3_MAX

constexpr uint8_t EV3UartGenerator::Framing::PAYLOAD_SENSOR_TO_EV3_MAX { 0x20 }

Maximum size of any payload sent in the EV3 UART sensor protocol, in bytes, to the EV3.

Definition at line 40 of file framing.hpp.

Referenced by frame_data_message(), and frame_info_message_name().

◆ SYMBOL_MAX

constexpr uint8_t EV3UartGenerator::Framing::SYMBOL_MAX { 0x08 }

Maximum length of the string representation (ASCII) of any symbol referencing a the SI unit used to represent the data output from a sensor, in a particular mode.

Definition at line 43 of file framing.hpp.

Referenced by frame_info_message_symbol().

Functions

Variables

Function Documentation

◆ checksum()

◆ frame_cmd_modes_message()

◆ frame_cmd_select_message()

◆ frame_cmd_speed_message()

◆ frame_cmd_type_message()

◆ frame_cmd_write_message()

◆ frame_data_message()

◆ frame_info_message_format()

◆ frame_info_message_name()

◆ frame_info_message_span()

◆ frame_info_message_symbol()

◆ frame_sys_message()

◆ insert_padding()

◆ length_code()

◆ log2()

Variable Documentation

◆ BUFFER_MIN

◆ PAYLOAD_EV3_TO_SENSOR_MAX

◆ PAYLOAD_MIN

◆ PAYLOAD_SENSOR_TO_EV3_MAX

◆ SYMBOL_MAX