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api / mbed / trunk / SPI

SPI

class SPI : public Base

A SPI Master, used for communicating with SPI slave devices

The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz

Most SPI devices will also require Chip Select and Reset signals. These can be controlled using DigitalOut pins

Example

// Send a byte to a SPI slave, and record the response

#include "mbed.h"

SPI device(p5, p6, p7); // mosi, miso, sclk

int main() {
    int response = device.write(0xFF);
}

SPI	A SPI Master, used for communicating with SPI slave devices
Functions
SPI	Create a SPI master connected to the specified pins
format	Configure the data transmission format
frequency	Set the spi bus clock frequency
write	Write to the SPI Slave and return the response

Functions

SPI

SPI( PinName mosi,
PinName miso,
PinName sclk,
const char * name = NULL )

Create a SPI master connected to the specified pins

Variables

mosi	SPI Master Out, Slave In pin
miso	SPI Master In, Slave Out pin
sclk	SPI Clock pin
name	(optional) A string to identify the object

Pin Options

(5, 6, 7) or (11, 12, 13)

mosi or miso can be specfied as NC if not used

format

void format( int bits,
int mode = 0 )

Configure the data transmission format

Variables

bits	Number of bits per SPI frame (4 - 16)
mode	Clock polarity and phase mode (0 - 3)

mode | POL PHA
-----+--------
  0  |  0   0
  1  |  0   1
  2  |  1   0
  3  |  1   1

frequency

void frequency( int hz = 1000000 )

Set the spi bus clock frequency

Variables

hz	SCLK frequency in hz (default = 1MHz)

write

virtual int write( int value )

Write to the SPI Slave and return the response

Variables

value	Data to be sent to the SPI slave
returns	Response from the SPI slave

class SPI : public Base

A SPI Master, used for communicating with SPI slave devices

SPI( PinName mosi,
PinName miso,
PinName sclk,
const char * name = NULL )

Create a SPI master connected to the specified pins

void format( int bits,
int mode = 0 )

Configure the data transmission format

void frequency( int hz = 1000000 )

Set the spi bus clock frequency

virtual int write( int value )

Write to the SPI Slave and return the response

class DigitalOut : public Base

A digital output, used for setting the state of a pin