SPI

Reads and writes the SPI bus (as Controller).

Reads and writes the SPI bus (as Controller).

Constants

Constant	Meaning
const uint8_t SPI_CONF::MSBFIRST	MSB as the first bit
const uint8_t SPI_CONF::LSBFIRST	make LSB the first bit
const uint8_t SPI_CONF::SPI_MODE0	set SPI MODE 0
const uint8_t SPI_CONF::SPI_MODE1	set to SPI MODE 1
const uint8_t SPI_CONF::SPI_MODE2	set to SPI MODE 2
const uint8_t SPI_CONF::SPI_MODE3	set to SPI MODE 3

Initialization and termination

The procedure for using the SPI bus depends on the begin() method.

Reads and writes the SPI bus (MASTER).

begin()

void begin(uint8_t slave_select, SPISettings settings)
SPISettings(uint32_t clock, uint8_t bitOrder, uint8_t dataMode)

Initialize hardware.

This process is also required after sleep recovery.

Parameters	Description
slave_select	Specify the SPI slave select pin to be used. 0 : DIO19, 1 : DIO0 (DIO 19 is reserved), 2 : DIO1 (DIO 0,19 is reserved)
settings	Specifies the SPI bus setting. The clock[hz] specifies the SPI bus frequency. A divisor closer to the specified frequency will be selected: 16Mhz or 16Mhz divided by an even number. bitOrder specifies SPI_CONF::MSBFIRST or SPI_CONF::LSBFIRST. dataMode specifies SPI_CONF::SPIMODE0..3.

Example

void setup() {
  ...
  SPI.begin(0, SPISettings(2000000, SPI_CONF::MSBFIRST, SPI_CONF::SPI_MODE3));
  ...
}

void wakeip() {
  ...
  SPI.begin(0, SPISettings(2000000, SPI_CONF::MSBFIRST, SPI_CONF::SPI_MODE3));
  ...
}

end()

void end()

Terminate the use of SPI hardware.

Reading and Writing

There are two types of read/write procedures. Select and use one of them.

• Member function version (input/output using the following member functions) beginTransaction(), endTransaction(), transfer(), transfer16(), transfer32()
• Helper class version (stream function available) transceiver