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SPISlave

SPISlave

class SPISlave : public Base

A SPI slave, used for communicating with a SPI Master device

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

Example

// Reply to a SPI master as slave

#include "mbed.h"

SPISlave device(p5, p6, p7, p8); // mosi, miso, sclk, ssel

int main() {
    device.reply(0x00);              // Prime SPI with first reply
    while(1) {
        if(device.receive()) {
            int v = device.read();   // Read byte from master
            v = (v + 1) % 0x100;     // Add one to it, modulo 256
            device.reply(v);         // Make this the next reply
        }
    }
}

SPISlave	A SPI slave, used for communicating with a SPI Master device
Functions
SPI	Create a SPI slave connected to the specified pins
format	Configure the data transmission format
frequency	Set the spi bus clock frequency
receive	Polls the SPI to see if data has been received
read	Retrieve data from receive buffer as slave
reply	Fill the transmission buffer with the value to be written out as slave on the next received message from the master.

Functions

SPI

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

Create a SPI slave connected to the specified pins

Variables

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

Pin Options

(5, 6, 7i, 8) or (11, 12, 13, 14)

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)

receive

int receive( void )

Polls the SPI to see if data has been received

Variables

returns

zero if no data, 1 otherwise

read

int read( void )

Retrieve data from receive buffer as slave

Variables

returns

the data in the receive buffer

reply

void reply( int value )

Fill the transmission buffer with the value to be written out as slave on the next received message from the master.

Variables

value

the data to be transmitted next

class SPISlave : public Base

A SPI slave, used for communicating with a SPI Master device

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

Create a SPI slave 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

int receive( void )

Polls the SPI to see if data has been received

int read( void )

Retrieve data from receive buffer as slave

void reply( int value )

Fill the transmission buffer with the value to be written out as slave on the next received message from the master.