File content as of revision 0:2211888e98cf:

#include "mbed.h"
Serial pc(USBTX, USBRX);          // tx, rx
//SPI spi(D11, D12, D13);              // mosi, miso, sclk
//DigitalOut cs(D10);                //slave select or chip select
SPI spi(PTE18, PTE19, PTE17);              // mosi, miso, sclk
DigitalOut cs(PTE5);                //slave select or chip select
#define RF22_REG_00_DEVICE_TYPE                         0x00

uint8_t readreg(uint8_t reg)
{
    int val;cs = 0;__disable_irq();spi.write(reg & ~0x80);val = spi.write(0);__enable_irq();cs = 1;return val;
}
int main()
{
    wait(1);                     // wait for POR to complete   //change the timing later
    cs=1;                          // chip must be deselected
    wait(1);                    //change the time later
    spi.format(8,0);
    spi.frequency(10000000);       //10MHz SCLK    
    if (readreg(RF22_REG_00_DEVICE_TYPE) == 0x08) pc.printf("spi connection valid\n");
    else pc.printf("error in spi connection\n");
}