The main header code of the C wrapper for libpruw1. More...

This graph shows which files directly or indirectly include this file:

Classes
struct	pruw1
	The PruW1 C wrapper structure. More...

Macros
#define	pruw1_scanBus(W1) pruw1_scanBus(W1, 0xF0)

Typedefs
typedef unsigned char	UInt8
	8 bit unsigned integer data type.

typedef short	Int16
	16 bit signed integer data type.

typedef int	Int32
	32 bit signed integer data type.

typedef unsigned int	UInt32
	32 bit unsigned integer data type.

typedef unsigned long long int	UInt64
	64 bit unsigned integer data type.

typedef struct pruw1	pruw1
	forward declaration More...

Enumerations
enum	LineModus { PRUW1_PARPOW = &b01 , PRUW1_PULLUP = &b10 , PRUW1_PARPOW = 0x1 , PRUW1_PULLUP = 0x2 }
	Masks for line idle configuration. More...

Functions
Int16	T_FAM10 (UInt8 *Rom)
	Compute the temperature for a series 10 sensor (old format). More...

Int16	T_FAM20 (UInt8 *Rom)
	Compute the temperature for a series 20 sensor (new format). More...

pruw1 *	pruw1_new (pruIo *P, UInt8 B, UInt8 M)
	Wrapper function for the constructor PruW1::PruW1(). More...

void	pruw1_destroy (pruw1 *W1)
	Wrapper function for the destructor PruW1::~PruW1(). More...

char *	pruw1_scanBus (pruw1 *W1, UInt8 SearchType)
	Function to scan the bus for all devices. More...

void	pruw1_sendByte (pruw1 *W1, UInt8 V)
	Send a byte (eight bits) to the bus. More...

void	pruw1_sendRom (pruw1 *W1, UInt64 V)
	Send a ROM ID to the bus (to select a device). More...

UInt8	pruw1_recvBlock (pruw1 *W1, UInt8 N)
	Receive a block of data (usually 9 bytes). More...

UInt8	pruw1_recvByte (pruw1 *W1)
	Receive a single byte (8 bit). More...

UInt8	pruw1_getIn (pruw1 *W1)
	Get the state of the data line. More...

UInt8	pruw1_resetBus (pruw1 *W1)
	Send the reset signal to the bus. More...

UInt8	pruw1_checkPara (pruw1 *W1)
	Check line for parasite powered device. More...

UInt8	pruw1_calcCrc (pruw1 *W1, UInt8 N)
	Compute the CRC checksum for data package. More...

Int32	pruw1_getSlotMax (pruw1 *W1)
	Property to get size of array PruW1::Slots from C. More...

void	pruw1_eraseSlots (pruw1 *W1)
	Function to empty the array PruW1::Slots from C. More...

UInt64	pruw1_getId (pruw1 *W1, UInt32 N)
	Function to get ID from array PruW1::Slots from C. More...

Detailed Description

The main header code of the C wrapper for libpruw1.

This file provides the declarations of macros, types and classes in C syntax. Include this file in your code to make use of libpruw1. This file contains a translation of the context of all FreeBASIC headers (pruw1.bi) in one file.

Feel free to translate this file in order to create language bindings for non-C languages in order to use libpruio in polyglot applications.

Licence: LGPLv2 (http://www.gnu.org/licenses/lgpl-2.0.html)

Definition in file pruw1.h.

Typedef Documentation

◆ pruw1

typedef struct pruw1 pruw1

forward declaration

The PruW1 C wrapper structure.

The class providing the one wire features.

Since: 0.0

Definition at line 26 of file pruw1.h.

Enumeration Type Documentation

◆ LineModus

enum LineModus

Masks for line idle configuration.

This enumerators are for use in CTOR PruW1::PruW1() to configure the line idle modus, regarding parasite power support and the use of the internal pull up resistor.

Since: 0.4

Enumerator
PRUW1_PARPOW	Set line output high during idle.
PRUW1_PULLUP	Activate internal pull up resistor (default)
PRUW1_PARPOW	Set line output high during idle.
PRUW1_PULLUP	Activate the internal pull up resistor.

Definition at line 73 of file pruw1.h.

Function Documentation

◆ pruw1_calcCrc()

UInt8 pruw1_calcCrc	(	pruw1 *	W1,
		UInt8	N
	)

Compute the CRC checksum for data package.

Parameters

W1	The driver instance.
N	The length of the package in bytes.

Returns: The CRC checksum for a data package (0 = success).

A data package (usually the 64-bit scratchpad context) is in the PRU DRam after a PruW1::readBlock() operation. This function computes the CRC checksum for a package with a given length. The length parameter specifies where to find the CRC byte, so in case of an 8 byte package length has to be 9 (= the same value as in the PruW1::readBlock() call).

Since: 0.0

◆ pruw1_checkPara()

UInt8 pruw1_checkPara ( pruw1 * W1 )

Check line for parasite powered device.

Returns: TRUE (1) if at least one device uses parasite power, FALSE (0) otherwise.

This function triggers a broadscast READ POWER command. The returned value is the byte received. If the function returns FALSE (0) there's no parasite powered device on the bus (all VDD=3V3). In contrast, TRUE (1) means at least one device has no external power line (VDD=GND) and needs the strong pullup in idle mode.

Since: 0.4

◆ pruw1_destroy()

void pruw1_destroy ( pruw1 * W1 )

Wrapper function for the destructor PruW1::~PruW1().

Parameters

W1	The driver instance.

Since: 0.0

◆ pruw1_eraseSlots()

void pruw1_eraseSlots ( pruw1 * W1 )

Function to empty the array PruW1::Slots from C.

Parameters

W1	The driver instance.

Auxiliary function to work aroung a missing feature in C syntax.

Since: 0.0

◆ pruw1_getId()

UInt64 pruw1_getId	(	pruw1 *	W1,
		UInt32	N
	)

Function to get ID from array PruW1::Slots from C.

Parameters

W1	The driver instance.
N	The number of the slot entry.

Auxiliary function to work aroung a missing feature in C syntax.

Since: 0.2

◆ pruw1_getIn()

UInt8 pruw1_getIn ( pruw1 * W1 )

Get the state of the data line.

Parameters

W1	The driver instance.

Returns: The state (1 = high, 0 = low)

This function returns the current state of the GPIO line used for the bus. The function uses libpruio to fetch the state, so only use it after the PruIo::config() call.

Since: 0.0

◆ pruw1_getSlotMax()

Int32 pruw1_getSlotMax ( pruw1 * W1 )

Property to get size of array PruW1::Slots from C.

Parameters

W1	The driver instance.

Returns: The number of elements array PruW1::Slots.

Auxiliary function to work aroung a missing feature in C syntax.

Since: 0.0

◆ pruw1_new()

pruw1* pruw1_new	(	pruIo *	P,
		UInt8	B,
		UInt8	M
	)

Wrapper function for the constructor PruW1::PruW1().

Parameters

P	A pointer to the libpruio instance (for pinmuxing).
B	The header pin to use as W1 bus data line.
M	The operating modus (Parasite power, internal pull-up).

Returns: A pointer to the new instance, call pruw1_destroy() when done.

The constructor is designed to

allocate and initialize memory for the class variables,
evaluate the free PRU (not used by libpruio)
check the header pin configuration (and, if not matching, try to adapt it - pinmuxing),
load the firmware and start it

In case of success the variable PruW1::Errr is 0 (zero), ready for starting the communication on the bus. Otherwise the variable contains an error message. The string is owned by libpruw1 and should not be freed. In that case call the destructor (and do not start any communication).

The operating modus M is introduced in version 0.4 in order to influence power consumption (ie. for batterie powered systems):

Bit-0 controlls the idle state of the line during sensor operation. By default the line is in input state (only the pull-up resistor pulls the line high). Set this bit in order to bring the line in high output state during sensor operation for parasite powering.

Note: For parasite powering the sensor VDD line must get grounded. The sensors current is up to 1.5 mA, so you must not run more than 4 sensors in parasite powering on a BBB-GPIO.

Bit-1 controlls the resistor configuration. By default By default the internal pull-up resistor pulls the line high, so that a sensor can operate without any further wiring. For long cables use an external resistor (usually 4k7 Ohm). Clear the bit in oder to save some energy consumption.

Since: 0.0

◆ pruw1_recvBlock()

UInt8 pruw1_recvBlock	(	pruw1 *	W1,
		UInt8	N
	)

Receive a block of data (usually 9 bytes).

Parameters

W1	The driver instance.
N	The number of bytes to read.

Returns: The number of bytes read.

This function triggers the bus to receive a block of bytes. Parameter N specifies the number of bytes to read. The return value is the number of bytes read, or 0 (zero) in case of an error (message text in PruW1::Errr). The received data bytes are in the PruW1::DRam, starting at byte offset &h10 (= DRam[4]).

Note: When compiled with monitor feature, the maximum block size is 112 bytes, due to limited size of logging memory (PruW1::DRam)

Since: 0.0

◆ pruw1_recvByte()

UInt8 pruw1_recvByte ( pruw1 * W1 )

Receive a single byte (8 bit).

Parameters

W1	The driver instance.

Returns: The byte read from the bus.

This function triggers the bus to receive a single byte. The return value is the byte received.

Since: 0.0

◆ pruw1_resetBus()

UInt8 pruw1_resetBus ( pruw1 * W1 )

Send the reset signal to the bus.

Parameters

W1	The driver instance.

Returns: The presence pulse from the bus.

This function sends the reset signal to the bus. It uses special timing. After the reset signal all devices answer by a presence pulse, so that the master knows that slave devices are on the bus. In that case the return value is 0 (zero). Otherwise, in case of no devices are responding, the return value is 1.

Since: 0.0

◆ pruw1_scanBus()

char* pruw1_scanBus	(	pruw1 *	W1,
		UInt8	SearchType
	)

Function to scan the bus for all devices.

Parameters

W1	The driver instance.
SearchType	The search type (defaults to &hF0).

Returns: An error message or 0 (zero) on success.

This function scans the bus and collects the IDs of the found devices (if any) in the array Slots. By default it uses the default search ROM command (&hF0).

Find the number of devices by evaluating the upper bound of array Slots, using function getSlotsSize().

Note: Usually the bus gets scanned once in the init process of an application. When you intend to use dynamic sensor connections (plug them in and out), then you have to periodically re-scan the bus. In that case clear the Slots array before each scan, in order to avoid double entries by function eraseSlots().

Since: 0.0

◆ pruw1_sendByte()

void pruw1_sendByte	(	pruw1 *	W1,
		UInt8	V
	)

Send a byte (eight bits) to the bus.

Parameters

W1	The driver instance.
V	The value to send.

This procedure sends a byte to the bus. It's usually used to issue a ROM command.

Since: 0.0

◆ pruw1_sendRom()

void pruw1_sendRom	(	pruw1 *	W1,
		UInt64	V
	)

Send a ROM ID to the bus (to select a device).

Parameters

W1	The driver instance.
V	The ROM ID (8 btes) to send.

This procedure sends a ROM ID to the bus. It's usually used to adress a single device, ie. to read its scratchpad.

Since: 0.0

◆ T_FAM10()

Int16 T_FAM10 ( UInt8 * Rom )

Compute the temperature for a series 10 sensor (old format).

Parameters

Rom	The pointer where to find the data received from the device.

Returns: The temperature (high byte = decimal value, low byte = digits).

This function decodes the temperature value from a DS18S20 sensor (such sensors have &h10 in the lowest byte of their ID). The returned value contains the temperature in grad Celsius in the high byte and the decimal places in the low byte. Divide the value by 256 to get a real number containing the temperatur in grad Celsius.

Parameter Rom is usually the adress of PruW1::DRam[4].

Since: 0.0

◆ T_FAM20()

Int16 T_FAM20 ( UInt8 * Rom )

Compute the temperature for a series 20 sensor (new format).

Parameters

Rom	The pointer where to find the data received from the device.

Returns: The temperature (high byte = decimal value, low byte = digits).

This function decodes the temperature value from a DS18B20 sensor (such sensors have &h20 in the lowest byte of their ID). The returned value contains the temperature in grad Celsius in the high byte and the decimal places in the low byte. Divide the value by 256 to get a real number containing the temperatur in grad Celsius.

Parameter Rom is usually the adress of PruW1::DRam[4].

Since: 0.0

Classes

Macros

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

◆ pruw1

Enumeration Type Documentation

◆ LineModus

Function Documentation

◆ pruw1_calcCrc()

◆ pruw1_checkPara()

◆ pruw1_destroy()

◆ pruw1_eraseSlots()

◆ pruw1_getId()

◆ pruw1_getIn()

◆ pruw1_getSlotMax()

◆ pruw1_new()

◆ pruw1_recvBlock()

◆ pruw1_recvByte()

◆ pruw1_resetBus()

◆ pruw1_scanBus()

◆ pruw1_sendByte()

◆ pruw1_sendRom()

◆ T_FAM10()

◆ T_FAM20()