Diff: main.cpp

Revision:

12:5e4cba1182ab

Parent:

11:0e42dd431fb5

Child:

13:8d9c273b607d

--- a/main.cpp	Sun Jul 14 21:18:39 2013 +0000
+++ b/main.cpp	Sun Jul 14 22:38:44 2013 +0000
@@ -1,3 +1,14 @@
+//This main funtion mainly implements a mode transfer.
+//When mcu resets, it's in MODE_IDLE. Then depends on the keyboard input, the 
+//mode switches to transition modes such as 
+//MODE_CHAxPHA, which is for phase input of channel x, or
+//MODE_CHAxAMP, which is for attenuation input of channel x, or
+//MODE_DISPLAY, which is for displaying the current parameters, or
+//MODE_HELP, which is for displaying the help infomation, or
+//MODE_SEND, which is for sending the bit stream through the SPI bus.
+//After each transition mode completes, mcu returns to MODE_IDLE to wait for another user input.
+
+
 #include "mbed.h"
 #include "menu.h"
 #include "parameters.h"
@@ -16,14 +27,14 @@
 
 unsigned short spi_stream;
 
-char line_buf[4];   //line_buf[3] is used to indicate if it's empty 0 empty 1 not
+char line_buf[4];   //line_buf[3] is used to indicate if it's empty 0 empty 1 not, other bytes for char data
 int line_pt;        //line buffer pointer points to next buffer location it's going to write
 int line_length;    //store the current line length
 int i;
 
 int main() {
 
-    pc.baud(19200);  //config buad rate 
+    pc.baud(19200);  //config buad rate. Note: 115200 seems too high for the current board
     state = MODE_IDLE;
     line_buf[3] = 0;
     line_buf[2] = 255;
@@ -65,7 +76,7 @@
                 line_pt = 0;
                 line_length = 0;
                 
-                while(1)   //input into line buffer, terminated by enter key
+                while(1)   //Character input into line buffer, terminated by enter key
                 {
                     recv = pc.getc();
                     if(recv == 13)   //enter is pressed, break
@@ -110,7 +121,7 @@
                     }
                 }
                 //input over, now checking 
-                //check phase input
+                //check phase shift input
                 if(state == MODE_CHA1PHA || state == MODE_CHA2PHA)
                 {  
                    if(state == MODE_CHA1PHA)
@@ -202,7 +213,7 @@
                 state = MODE_IDLE;  //back to idle state after input
                 break;
             
-            // in display mode
+            // In display mode, show current parameters
             case MODE_DISPLAY:
                 
                 pc.printf("Phase shift value for channel 1 is %d degrees\n", cha1_pha*-7);
@@ -213,7 +224,7 @@
                 pc.getc();
                 state = MODE_IDLE;
                 break;
-                
+            //Help mode, displays help info   
             case MODE_HELP:
                 
                 pc.printf("%s", msg_help);
@@ -222,7 +233,7 @@
                 state = MODE_IDLE;
                 break;
                 
-            case MODE_SEND:
+            case MODE_SEND:  //In sending mode, display and send through SPI
                 
                 pc.printf("Phase shift value for channel 1 is %d degrees\n", cha1_pha*-7);
                 pc.printf("Phase shift value for channel 2 is %d degrees\n", cha2_pha*-7);