Diff: main.cpp

Revision:

0:75151492e147

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Oct 15 21:27:29 2012 +0000
@@ -0,0 +1,45 @@
+/*Program Example 7.9: Sets the mbed up for async communication, and exchanges data with a similar node, sending its own switch positions, and displaying those of the other. 
+                                                                 */
+#include "mbed.h"
+Serial async_port(p9, p10);          //set up TX and RX on pins 9 and 10
+DigitalOut red_led(p25);             //red led
+DigitalOut green_led(p26);           //green led
+DigitalOut strobe(p7);               //a strobe to trigger the scope
+DigitalIn switch_ip1(p5);
+DigitalIn switch_ip2(p6);
+char switch_word ;                   //the word we will send
+char recd_val;                       //the received value 
+  
+int main() {
+  async_port.baud(9600);             //set baud rate to 9600 (ie default)
+  //accept default format, of 8 bits, no parity
+  while (1){
+    //Set up the word to be sent, by testing switch inputs
+    switch_word=0xa0;                 //set up a recognisable 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
+    strobe =1;                        //short strobe pulse 
+    wait_us(10);
+    strobe=0;
+    async_port.putc(switch_word);     //transmit switch_word
+    if (async_port.readable()==1)     //is there a character to be read?
+      recd_val=async_port.getc();     //if yes, then read it
+
+    //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;
+    }
+
+  }
+}
+