Diff: main.cpp

Revision:

0:795863b0916e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Sep 26 00:04:44 2014 +0000
@@ -0,0 +1,53 @@
+/*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(D11, D12, D13);        // mosi, miso, sclk
+DigitalOut red_led(LED_RED);        //red led
+DigitalOut green_led(LED_GREEN);    //green led
+DigitalOut cs(D2);                  //this acts as “slave select”
+DigitalIn  switch_ip1(SW2);
+DigitalIn  switch_ip2(SW3);
+ 
+char switch_word ;                  //word we will send
+char recd_val;                      //value return from slave
+
+//continued over
+
+int main() {
+    switch_ip1.mode(PullUp);
+    switch_ip2.mode(PullUp);
+    red_led = 1;
+    green_led=1;
+    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 recognisable output pattern
+        if (switch_ip1==0)
+          switch_word=switch_word|0x01;        //OR in lsb
+        if (switch_ip2==0)
+          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=1;              //preset both to 0
+        green_led=1; 
+        recd_val=recd_val&0x03; //AND out unwanted bits
+        
+        if (recd_val==0x1)
+          red_led=0;
+        
+        if (recd_val==0x2)
+          green_led=0;
+        
+        if (recd_val==0x3){
+          red_led=0;
+          green_led=0;
+        }
+
+    }    
+} 
\ No newline at end of file