main.cpp

00001 #include "mbed.h"
00002 
00003 DigitalOut myled(LED1);
00004 
00005 Serial pc (USBTX,USBRX);
00006 
00007 SPI spi (p5,p6,p7);
00008 DigitalOut cs (p8);
00009 
00010 int main() {
00011 
00012     spi.format(8,2);
00013 
00014     // set initial state of CS pin
00015     cs = 0;
00016     wait (0.1);    
00017     
00018 // start by clearing WP in Control register
00019 // the RAM can not be accessed until WP is clear
00020     
00021     cs = 1;
00022     wait (0.1);    
00023     spi.write (0x8f); // write to control register
00024     spi.write(0x0); // clear all the bits
00025     cs = 0;
00026     
00027     wait (0.1);
00028     
00029 // Now write to the RAM
00030     cs = 1;
00031     wait (0.1);    
00032     spi.write (0xA0); // write to first RAM location
00033     spi.write(0xa5);  // set a pattern
00034     cs = 0;
00035 
00036     wait (0.1);
00037 
00038 // Now read from RAM
00039     cs = 1;
00040     wait (0.1);    
00041     spi.write (0x20); // read from first RAM location
00042     char data = spi.write(0x00); 
00043     cs = 0;
00044 
00045 
00046     printf("Read from location 0x20 and received 0x%X\n",data);
00047 
00048 
00049     while (1) {}
00050 
00051 }