File content as of revision 0:bf809e86f7da:

 /*Program Example 7.2. Sets the mbed up as Master, and exchanges data with a slave,
sending its own switch positions, and displaying those of the slave.
*/
#include "mbed.h"
SPI ser_port(p11, p12, p13); //mosi, miso, sclk
DigitalOut red_led(p25); //red led
DigitalOut green_led(p26); //green led

DigitalOut cs(p14); //this acts as “slave select”

DigitalIn switch_ip1(p5);
DigitalIn switch_ip2(p6);

char switch_word ; //word we will send
char recd_val; //value return from slave

int main() 
{
    while (1){
    //Default settings for SPI Master chosen, no need for further configuration
    //Set up the word to be sent, by testing switch inputs
    switch_word=0xa0; //set up a recognizable output pattern
    if (switch_ip1==1)
        switch_word=switch_word | 0x01; //OR in lsb
    if (switch_ip2==1)
        switch_word=switch_word | 0x02; //OR in next lsb
    cs = 0; //select slave
    recd_val=ser_port.write(switch_word); //send switch_word and receive data
    cs = 1;
    wait(0.01);
    //set leds according to incoming word from slave
    red_led=0; //preset both to 0
    green_led=0;
    recd_val=recd_val & 0x03; //AND out unwanted bits
    if (recd_val==1)
        red_led=1;
    if (recd_val==2)
        green_led=1;
    if (recd_val==3){
        red_led=1;
        green_led=1;
                }
    }
}