menu_robot.c

Embedded C 这本书的范例光碟程式

/*------------------------------------------------------------------*-

   Menu_Robot.C (v1.00)

  ------------------------------------------------------------------

   Simple framework for controlling a robot over a serial link.

   On PC use, 'Hyperterminal' (under Windows 95, 98, 2000) or similar 
   terminal emulator program on other operating systems.

   Terminal options: 

   - Data bits    = 8
   - Parity       = None
   - Stop bits    = 1
   - Flow control = Xon / Xoff 

   COPYRIGHT
   ---------

   This code is associated with the book:

   EMBEDDED C by Michael J. Pont 
   [Pearson Education, 2002: ISBN: 0-201-79523-X].

   This code is copyright (c) 2001 by Michael J. Pont.
 
   See book for copyright details and other information.

-*------------------------------------------------------------------*/

#include "Main.H"
#include "Port.H"

#include "Menu_Robot.h"
#include "PC_IO.h"

// ------ Public variable declarations -----------------------------
// See Stepper.c
extern bit Motor_L;
extern bit Motor_R;

// ------ Private variables ----------------------------------------
static bit First_time_only_G;


/*------------------------------------------------------------------*-

  MENU_Command_Processor()

  This function is the main menu 'command processor' function.  

  Call this (say) once every 10 ms (approx.).

-*------------------------------------------------------------------*/
void MENU_Command_Processor(void)
   {
   char Ch;

   if (First_time_only_G == 0)
      {
      First_time_only_G = 1;
      MENU_Show_Menu();
      }

   // Check for user inputs
   PC_LINK_IO_Update();

   Ch = PC_LINK_IO_Get_Char_From_Buffer();
      
   if (Ch != PC_LINK_IO_NO_CHAR)
      {
      MENU_Perform_Task(Ch);
      MENU_Show_Menu();
      }
   }


/*------------------------------------------------------------------*-

  FUNCTION: MENU_Show_Menu()

  Display menu options on PC screen (via serial link)
  - edit as required to meet the needs of your application.

  HARDWARE: -

  GLOBALS:  -

  PARAMS:   void 

  RETURNS:  void

-*------------------------------------------------------------------*/
void MENU_Show_Menu(void)
   {
   PC_LINK_IO_Write_String_To_Buffer("a - Ahead\n");
   PC_LINK_IO_Write_String_To_Buffer("l - Left\n");
   PC_LINK_IO_Write_String_To_Buffer("r - Right\n");
   PC_LINK_IO_Write_String_To_Buffer("s - STOP\n\n");
   PC_LINK_IO_Write_String_To_Buffer("? : ");
   }


/*------------------------------------------------------------------*-

  FUNCTION: MENU_Perform_Task()

  Perform the required user task
  - edit as required to match the needs of your application.

  HARDWARE: Uses the on-chip UART hardware.

  GLOBALS:  -

  PARAMS:   void 

  RETURNS:  void

-*------------------------------------------------------------------*/
void MENU_Perform_Task(char c)
   {
   // Echo the menu option
   PC_LINK_IO_Write_Char_To_Buffer(c);
   PC_LINK_IO_Write_Char_To_Buffer('\n');

   // Perform the task
   switch (c)
      {
      case 'a':
      case 'A':
         {
         PC_LINK_IO_Write_String_To_Buffer("<*> AHEAD\n\n");
         Motor_L = 1;
         Motor_R = 1;
         break;
         }
      
      case 'l':
      case 'L':
         {
         PC_LINK_IO_Write_String_To_Buffer("<** LEFT\n\n");
         Motor_L = 0;
         Motor_R = 1;
         break;
         }

      case 'r':
      case 'R':
         {
         PC_LINK_IO_Write_String_To_Buffer("**> RIGHT\n\n");
         Motor_L = 1;
         Motor_R = 0;
         break;
         }

      case 's':
      case 'S':
         {
         PC_LINK_IO_Write_String_To_Buffer("*** STOP\n\n");
         Motor_L = 0;
         Motor_R = 0;
         }
      } 
   }

/*------------------------------------------------------------------*-
  ---- END OF FILE -------------------------------------------------
-*------------------------------------------------------------------*/