SPI

Functions
void	begin ()
void	end ()
uint16_t	transfer16 (uint16_t data)
void	transfer (void *buf, size_t count)
void	beginTransaction (SPISettings settings)
void	endTransaction ()
void	setBitOrder (BitOrder order)
void	setDataMode (uint8_t mode)
void	setClockDivider (uint32_t uc_div)

Detailed Description

Function Documentation

begin()

void begin

(

)

Description

Initializes the SPI bus by setting SCK, MOSI, and SS to outputs, pulling SCK and MOSI low, and SS high

Syntax

SPI.begin()

Returns

void

end()

void end

(

)

Description

Disables the SPI bus

Syntax

SPI.end()

Returns

void

transfer16()

uint16_t transfer16

(

uint16_t

data

)

Description

SPI transfer is based on a simultaneous send and receive: the received data is returned in receivedVal16.

Syntax

receivedVal16 = SPI.transfer16(val16)

Parameters

val16

the two bytes variable to send out over the bus

Returns

the received data

transfer()

void transfer	(	void *	buf,
		size_t	count
	)

Description

SPI transfer is based on a simultaneous send and receive: the received data is returned in receivedVal. In case of buffer transfers the received data is stored in the buffer in-place.

Syntax

receivedVal = SPI.transfer(val)
SPI.transfer(buffer, size)

Parameters

val	the byte to send out over the bus
buffer	the array of data to be transferred

Returns

the received data

beginTransaction()

void beginTransaction

(

SPISettings

settings

)

Description

Initializes the SPI bus using the defined SPISettings

Syntax

SPI.beginTransactions(mySetting)

Parameters

mySetting

the chosen settings according to SPISettings

Returns

void

endTransaction()

void endTransaction

(

)

Description

Stop using the SPI bus

Syntax

SPI.endTransaction()

Returns

void

setBitOrder()

void setBitOrder

(

BitOrder

order

)

Description

Sets the order of the bits shifted out of and into the SPI bus, either LSBFIRST (least-significant bit first) or MSBFIRST (most-significant bit first)

Syntax

SPI.setBitOrder(order)

Parameters

order

either LSBFIRST or MSBFIRST

Returns

void

setDataMode()

void setDataMode

(

uint8_t

mode

)

Description

Sets the SPI data mode: that is, clock polarity and phase

Syntax

SPI.setDataMode(mode)

Parameters

mode	SPI_MODE0 SPI_MODE1 SPI_MODE2 SPI_MODE3

Returns

void

setClockDivider()

void setClockDivider

(

uint32_t

uc_div

)

Description

Sets the SPI clock divider relative to the system clock

Syntax

SPI.setClockDivider(divider)

Parameters

divider

SPI_CLOCK_DIV2 SPI_CLOCK_DIV4 SPI_CLOCK_DIV8 SPI_CLOCK_DIV16 SPI_CLOCK_DIV32 SPI_CLOCK_DIV64 SPI_CLOCK_DIV128 SPI_CLOCK_DIV256

Returns

void