Main bbbandroidHAL header file. More...

#include <stdio.h>

Functions
int	openBBBAndroidHAL (void)

int	closeBBBAndroidHAL (void)

int	openGPIO (const int useMmap)

int	readGPIO (const unsigned int header, const unsigned int pin)

int	writeGPIO (const unsigned int header, const unsigned int pin, const unsigned int value)

void	closeGPIO (void)

int	pwmSetPeriod (const uint8_t channel, const uint32_t period_ns)

int	pwmGetPeriod (const uint8_t channel)

int	pwmSetDutyCycle (const uint8_t channel, const uint32_t duration_ns)

int	pwmGetDutyCycle (const uint8_t channel)

int	pwmSetPolarity (const uint8_t channel, const uint8_t polarity)

int	pwmGetPolarity (const uint8_t channel)

int	pwmRun (const uint8_t channel)

int	pwmStop (const uint8_t channel)

int	pwmRunCheck (const uint8_t channel)

int	readADC (const uint8_t channel)

int	i2cOpenAdaptor (const uint8_t adaptorNumber)

int	i2cSetSlave (const int i2cFD, const uint8_t address)

void	i2cClose (const int i2cFD)

int	i2cSetAddress (const int i2cFD, const uint8_t add)

int	i2cWriteByte (const int i2cFD, const uint8_t add, const uint8_t byte)

int	i2cWriteBytes (const int i2cFD, const uint8_t add, const int length, const uint8_t *bytes)

int	i2cReadByte (const int i2cFD, const uint8_t add)

int	i2cReadBytes (const int i2cFD, const uint8_t add, const int length, uint8_t *buff)

int	spiTransfer (const int spiFD, const uint8_t tx[], const uint8_t rx[], const int len)

int	spiOpen (const uint8_t bus, const uint8_t device, const uint32_t speed, const uint8_t mode, const uint8_t bpw)

int	spiReadByte (const int spiFD, const uint8_t regAdd)

unsigned char *	spiReadBytes (const int spiFD, const int len, const uint8_t startAdd)

int	spiWriteRegByte (const int spiFD, const uint8_t regAdd, const uint8_t data)

int	spiWriteBytes (const int spiFD, const uint8_t data[], const int len)

int	spiSetMode (const int spiFD, const uint8_t mode)

int	spiSetSpeed (const int spiFD, const uint32_t speed)

int	spiSetBitsPerWord (const int spiFD, const uint8_t bpw)

void	spiClose (const int spiFD)

int	canOpenSocket (const int socket_type, const int protocol)

int	canOpenRaw (const char *port)

unsigned char *	canReadBytes (const int fd, int *length)

int	canSendBytes (const int canFD, const int no_bytes, const uint8_t data[])

void	canClose (const int canFD)

int	uartOpen (const uint8_t device, const uint32_t bdrate)

int	uartWrite (const int uartFD, const int length, const uint8_t *bytes)

int	uartRead (const int uartFD, const int length, uint8_t *bytes)

void	uartClose (const int uartFD)

ssize_t	usbInit ()

void	usbClose ()

int	usbGetDevices (int ids[][8], unsigned char strings[][3][256])

Detailed Description

Main bbbandroidHAL header file.

Author: Ankur Yadav (ankur.nosp@m.ayad.nosp@m.av@gm.nosp@m.ail..nosp@m.com), Andrew Henderson (hende.nosp@m.rsa@.nosp@m.iccul.nosp@m.us.o.nosp@m.rg)

Function Documentation

void canClose ( const int canFD )

This function is used to close CAN file descriptor.

Parameters

canFD a constant integer argument.

int canOpenRaw ( const char * port )

This function takes port string as input and opens socket using canOpenSocket(), locates interface using ioctl() system call then binds the socket with CAN interface and returns the file descriptor.

Parameters

port	a constant character pointer argument.

See Also: canOpenSocket()

Returns: If successful then CAN file descriptor after opening socket is returned and if it fails then -1 is returned.

int canOpenSocket	(	const int	socket_type,
		const int	protocol
	)

This function takes socket_type and protocol as input and opens socket of that type and protocol and then returns file descriptor.

Parameters

socket_type	a constant integer argument.
protocol	a constant integer argument.

Returns: If successful then CAN file descriptor after opening socket is returned and if it fails then -1 is returned.

unsigned char* canReadBytes	(	const int	fd,
		int *	length
	)

This functions takes file descriptor and length of data to be read as input and returns the pointer to the array of data bytes read. If no data is read then NULL pointer is returned.

Parameters

fd	a constant integer argument.
length	a integer pointer argument.

Returns: The pointer to the array of data bytes read. If no data is read then NULL pointer is returned.

int canSendBytes	(	const int	canFD,
		const int	no_bytes,
		const uint8_t	data[]
	)

This function takes can file descriptor, number of bytes and array of data to be transferred as input and writes given number of bytes of data from data buffer.

Parameters

canFD	a constant integer argument.
no_bytes	a constant unsigned integer argument.
data	array of constant uint8_t argument.

Returns: number of bytes successfully written to CAN device.

void closeGPIO ( void )

For closing file descriptor if accessed using file system and set initialized to 0.

void i2cClose ( const int i2cFD )

This function is used to close I2C file descriptor.

Parameters

i2cFD a constant integer argument.

int i2cOpenAdaptor ( const uint8_t adaptorNumber )

This function takes I2C adapter number as input and returns a file descriptor for accessing that I2C adapter.

Parameters

adaptorNumber a constant uint8_t argument.

Returns: If successful then I2C file descriptor is returned and if it fails then -1 is returned.

int i2cReadByte	(	const int	i2cFD,
		const uint8_t	add
	)

It takes file descriptor and address of register from which data is to be read. It reads a byte from the address provided in input and returns the byte. It internally uses i2cSetAddress() to set pointer to proper address.

Parameters

i2cFD	a constant integer argument.
add	a constant uint8_t argument.

See Also: i2cSetAddress()

Returns: byte on success and -1 if it fails.

int i2cReadBytes	(	const int	i2cFD,
		const uint8_t	add,
		const int	length,
		uint8_t *	buff
	)

It takes file descriptor, starting address of register from which data is to be read, length of data to be read and buffer to store the data as input. It is used to get 'length' number of bytes in 'buff' array from 'add' starting address.

Parameters

i2cFD	a constant integer argument.
add	a constant uint8_t argument.
length	a constant integer argument.
bytes	an uint8_t pointer argument.

Returns: 0 on success and -1 if it fails.

int i2cSetAddress	(	const int	i2cFD,
		const uint8_t	add
	)

This is used by some other functions internally for random access of sensor registers. It takes file descriptor and random address as input to which file descriptor should point.

Parameters

i2cFD	a constant integer argument.
add	a constant uint8_t argument.

Returns: 0 on success and -1 if it fails.

int i2cSetSlave	(	const int	i2cFD,
		const uint8_t	address
	)

This takes I2C adapter file descriptor and address at which device is attached as input and sets slave for file descriptor using ioctl call.

Parameters

i2cFD	a constant integer argument.
address	a constant uint8_t argument.

Returns: If successful then 0 is returned and if it fails then -1 is returned.

int i2cWriteByte	(	const int	i2cFD,
		const uint8_t	add,
		const uint8_t	byte
	)

This function takes file descriptor, address of register to write and byte to be written as input and writes byte provided in the argument at the address provided.

Parameters

i2cFD	a constant integer argument.
add	a constant uint8_t argument.
byte	a constant uint8_t argument.

Returns: 0 on success and -1 if it fails.

int i2cWriteBytes	(	const int	i2cFD,
		const uint8_t	add,
		const int	length,
		const uint8_t *	bytes
	)

It takes i2c file descriptor, start address of registers to be written, length of data and array containing bytes of data as input. This function is used to write bytes provided in argument from the address provided to address+length continuously.

Parameters

i2cFD	a constant integer argument.
add	a constant uint8_t argument.
length	a constant integer argument.
bytes	a constant uint8_t pointer argument.

Returns: 0 on success and -1 if it fails.

int openGPIO ( const int useMmap )

This function takes parameter input useMmap to take choice if you want to use Memory Map to access GPIO or to access it using file system. If using memory map then a proper file descriptor is set.

Parameters

useMmap a constant integer argument.

Returns: If successful then 0 is returned and if it fails then 1 is returned.

int pwmGetDutyCycle ( const uint8_t channel )

It takes channel number as input and returns the value of duty cycle of specified channel in nano seconds.

Parameters

channel a constant uint8_t argument.

Returns: value of duty cycle on success and -1 if it fails.

int pwmGetPeriod ( const uint8_t channel )

It takes channel number as input and returns the value of period of specified channel in nano seconds.

Parameters

channel a constant uint8_t argument.

Returns: value of period on success and -1 if it fails.

int pwmGetPolarity ( const uint8_t channel )

It takes channel number as input and returns the value of polarity of specified channel.

Parameters

channel a constant uint8_t argument.

Returns: value of polarity on success and -1 if it fails.

int pwmRun ( const uint8_t channel )

It takes channel number as input and sets run for that channel so that pwm starts running for that channel.

Parameters

channel a constant uint8_t argument.

Returns: 0 on success and -1 if it fails.

int pwmRunCheck ( const uint8_t channel )

It takes channel number as input and returns the value of run for that channel.

Parameters

channel a constant uint8_t argument.

Returns: value of run on success and -1 if it fails.

int pwmSetDutyCycle	(	const uint8_t	channel,
		const uint32_t	duration_ns
	)

It takes channel and duty cycle to be assigned in nano seconds and sets duty cycle of that channel to specified value using file system.

Parameters

channel	a constant uint8_t argument.
duration_ns	a constant uint32_t argument.

Returns: 0 on success and -1 if it fails.

int pwmSetPeriod	(	const uint8_t	channel,
		const uint32_t	period_ns
	)

It takes channel and period to be assigned in nano seconds and sets period of that channel to specified value using file system.

Parameters

channel	a constant uint8_t argument.
period_ns	a constant uint32_t argument.

Returns: 0 on success and -1 if it fails.

int pwmSetPolarity	(	const uint8_t	channel,
		const uint8_t	polarity
	)

It takes channel and polarity to be assigned and sets polarity of that channel to the specified value using file system.

Parameters

channel	a constant uint8_t argument.
polarity	a constant uint8_t argument.

Returns: 0 on success and -1 if it fails.

int pwmStop ( const uint8_t channel )

It takes channel number as input and sets run to 0 for that channel so that pwm stops for that channel.

Parameters

channel a constant uint8_t argument.

Returns: 0 on success and -1 if it fails.

int readADC ( const uint8_t channel )

It takes ADC channel number as the input and reads its value using file system access and then returns its value.

Parameters

channel a constant uint8_t argument.

Returns: If successful then value of ADC channel is returned and if it fails then -1 is returned.

int readGPIO	(	const unsigned int	header,
		const unsigned int	pin
	)

It takes input GPIO header and pin and reads its value after opening its file. If Memory Map is used then proper bit value is read using the file descriptor initialized in openGPIO() function call. Proper bit positions for all the GPIOs are present in GPIOBit_t arrays of each P8 and P9 header.

Parameters

header	a constant unsigned int argument.
pin	a constant unsigned int argument.

See Also: readGPIOMmap(); readGPIOFS()

Returns: 1 if read 1 and 0 if read 0;

void spiClose ( const int spiFD )

This function is used to close SPI file descriptor.

Parameters

spiFD a constant integer argument.

int spiOpen	(	const uint8_t	bus,
		const uint8_t	device,
		const uint32_t	speed,
		const uint8_t	mode,
		const uint8_t	bpw
	)

This function takes input bus number, device number, speed of device, mode of device and bits per word for the device and internally opens the file and sets speed mode and bits per word for the device using spiSetMode(), spiSetSpeed() and spiSetBitsPerWord() and then returns the file descriptor.

Parameters

bus	a constant unsigned integer argument.
device	a constant uint8_t argument.
speed	a constant uint32_t argument.
mode	a constant uuint8_t argument.
bpw	a constant uuint8_t argument.

Returns: If successful then SPI file descriptor is returned and if it fails then -1 is returned.

int spiReadByte	(	const int	spiFD,
		const uint8_t	regAdd
	)

It takes spi file descriptor and register address as input and returns the value present at that address.

Parameters

spiFD	a constant integer argument.
regAdd	a constant uint8_t argument.

Returns: value present at that address.

unsigned char* spiReadBytes	(	const int	spiFD,
		const int	len,
		const uint8_t	startAdd
	)

It takes file descriptor, length of data to be read and starting address of register from which data is to be read and returns a pointer to the array of data bytes read. It is used to get 'length' number of bytes in array from 'startAdd' starting address.

Parameters

spiFD	a constant integer argument.
len	a constant integer argument.
startAdd	a constant uint8_t argument.

Returns: a pointer to the array of data bytes read.

int spiSetBitsPerWord	(	const int	spiFD,
		const uint8_t	bpw
	)

It takes file descriptor and 'bpw' bits per word as input and sets the bpw provided in the argument to the device represented by file descriptor.

Parameters

spiFD	a constant integer argument.
bpw	a constant uint8_t argument.

Returns: 0 if successful and -1 if it fails.

int spiSetMode	(	const int	spiFD,
		const uint8_t	mode
	)

It takes file descriptor and mode as input and sets the mode provided in the argument to the device represented by file descriptor.

Parameters

spiFD	a constant integer argument.
mode	a constant uint8_t argument.

Returns: 0 if successful and -1 if it fails.

int spiSetSpeed	(	const int	spiFD,
		const uint32_t	speed
	)

It takes file descriptor and speed as input and sets the speed provided in the argument to the device represented by file descriptor.

Parameters

spiFD	a constant integer argument.
speed	a constant uint32_t argument.

Returns: 0 if successful and -1 if it fails.

int spiTransfer	(	const int	spiFD,
		const uint8_t	tx[],
		const uint8_t	rx[],
		const int	len
	)

This function takes input SPI file descriptor, tx buffer array to transmit data, rx buffer array to receive data and length of data to be transferred. It then transfers and receives data using ioctl function call.

Parameters

spiFD	a constant integer argument.
tx	a constant uint8_t array argument.
rx	a constant uint8_t array argument.
len	a constant integer argument.

Returns: 0 if successful and -1 if it fails.

int spiWriteBytes	(	const int	spiFD,
		const uint8_t	data[],
		const int	len
	)

It takes spi file descriptor , array of data to be written and length of data to be written as input. It writes length number of data bytes from the data buffer provided.

Parameters

spiFD	a constant integer argument.
data	a constant uint8_t argument argument.
len	a constant integer argument.

Returns: 0

int spiWriteRegByte	(	const int	spiFD,
		const uint8_t	regAdd,
		const uint8_t	data
	)

This function takes file descriptor, address of register to write and byte to be written as input and writes byte provided in the argument at the address provided.

Parameters

spiFD	a constant integer argument.
regAdd	a constant uint8_t argument.
data	a constant uint8_t argument.

Returns: 0

void uartClose ( const int uartFD )

This function is used to close UART file descriptor.

Parameters

uartFD a constant integer argument.

int uartOpen	(	const uint8_t	device,
		const uint32_t	bdrate
	)

This takes device number and baud rate as input and opens uart deivce with specified baud rate and returns the file descriptor. It internally uses baudrate() to get proper value using macro.

Parameters

device	a constant uint8_t argument.
bdrate	a constant uint8_t argument.

See Also: baudrate()

Returns: If successful then UART file descriptor is returned and if it fails then -1 is returned.

int uartRead	(	const int	uartFD,
		const int	length,
		uint8_t *	bytes
	)

This functions takes file descriptor, length of data bytes to be received and pointer to array to store the bytes received as input and reads data from UART using read system call.

Parameters

uartFD	a constant integer argument.
length	a constant integer argument.
bytes	a constant uint8_t pointer argument.

Returns: 0 if successful and -1 if it fails.

int uartWrite	(	const int	uartFD,
		const int	length,
		const uint8_t *	bytes
	)

This function takes file descriptor, length of data bytes to be transferred and pointer to the array of bytes to be transferred as input and sends it using write system call.

Parameters

uartFD	a constant integer argument.
length	a constant integer argument.
bytes	a constant uint8_t pointer argument.

Returns: 0 if successful and -1 if it fails.

void usbClose ( )

This function is used to close USB devices.

int usbGetDevices	(	int	ids[][8],
		unsigned char	strings[][3][256]
	)

This function takes one 2D array to store IDs (bus, device, manufacturer and vendor) for each USB device and one 3D array to store path, manufacturer descriptor and vendor descriptor. It returns 0 if successful and -1 if it fails. It is only to demonstrate and develop lsusb kind of app. Similar functions can be made using libusb for other functionalities of USB.

Parameters

ids	2D integer array argument.
strings	3D unsigned character argument.

Returns: 0 if successful and -1 if it fails.

ssize_t usbInit ( )

It creates USB session and gets number of USB devices attached and then returns number of USB devices attached.

Returns: If successful then number of USB devices attached is returned and if it fails then -1 is returned.

int writeGPIO	(	const unsigned int	header,
		const unsigned int	pin,
		const unsigned int	value
	)

It takes input GPIO header, pin and value that is required to be set on GPIO after opening corresponding GPIO file. If Memory Map is used then proper bit value is set using the file descriptor initialized in openGPIO() function call. Proper bit positions for all the GPIOs are present in GPIOBit_t arrays of each P8 and P9 header.

Parameters

header	a constant unsigned int argument.
pin	a constant unsigned int argument.

See Also: writeGPIOMmap(); writeGPIOFS()

Returns: 0 if successfull and 1 if it fails

Functions

Detailed Description

Function Documentation