MEL PICBASIC Forum - Input routine and command parser

  • Input routine and command parser

    by
    Charles Linquis
    Published on - 11th September 2011 01:28  Number of Views: 7735  
    This routine takes keyboard input, including backspaces, and processes them through a command parser. It converts all chars (but not numbers) to uppercase before processing.

    It will run on your PICDem board.

    This example is actually 3 parts in one.

    Part number 1 (GetCharInput) is a routine that allows you to type and send text to the PIC. It echoes back valid characters, and lets you backspace if you make an error. It "rubs out" the backspace(d) characters, and it terminates when you hit <ENTER> or <ESC>. If you hit <ENTER> it returns the input in an array. If you hit <ESC> it wipes out the array and returns. If you do nothing for 9 seconds, it returns with an empty string.

    Part number 2 (ConvertToUpper) takes the input in mixed-case and converts all the alpha characters to upper case. It leaves numbers and punctuation "as-is". This is handy when you do compares, since people may or may not capitalize the right letters when they type something in.

    Part number 3 (ParseIt) takes the array and searches for any number of strings. When it finds a match, it returns a number that indicates which of the strings matched. This is really useful if you get random data from something like a GPS receiver, or from a network port - or anything.



    Enjoy.

    Code:
     '****************************************************************
;
;Name    : Code Example                                      
'*  Author  : Charles Linquist                                  
'*  Date    : 9/10/2011                                         
'*  Version :1.0                                               
'*  Notes  :  For the Forum                                                
'****************************************************************
 
        DEFINE OSC 40                                                           
 
        DEFINE NO_CLRWDT 1
        DEFINE _18F8723 1
        DEFINE HSER_RCSTA 90H
        DEFINE HSER_TXSTA 20H
        DEFINE HSER_BAUD 9600
        DEFINE HSER_CLROERR 1
        DEFINE LOADER_USED 1                                               
 
 
        TRISC = %10111111 
 
        MaxChars var byte
        Inputstring var byte [12]
        Timeout var word
        X var byte
        CharInput var byte
        InputString_Len Var Byte
        CMD VAR BYTE
 
 
        MaxChars = 10
        InputString_Len = MaxChars
        Timeout = 9000
 
        BS con 8
        CR CON 13
        LF CON 10
        ESC CON 27
        SP CON 32
 
 
topp:
 
 
    Gosub GetCharInput
     Gosub ConvertToUpper
    Gosub Parseit
 
    goto topp
 
 
;-------------------------------------------------------------------
GetCharInput:
 
HSEROUT [CR,LF,"Input ? "]
 
 
TextIn:
        ArrayWrite InputString,[REP 0\MaxChars] ; zero out the string to start with
        X = 0 
 
TextIn2:
        HSERIN Timeout,NoInput,[CharInput]
        IF CharInput = CR Then Goto DoneInput
        If CharInput = ESC THEN goto NoInput
           IF CharInput = BS THEN 
               IF X = 0 THEN
                Goto TextIn2 
           ELSE   
                HSEROUT [BS,SP,BS]
               X = X - 1
              InputString[x] = 0 ; zero out the backspaced char
              GOTO TextIn2
          ENDIF 
     ENDIF    
 
InputString[X] = CharInput
        HSEROUT [CharInput]      ; Show what we got                                                    
 
        IF X >= MaxChars then goto DoneInput
        X = X + 1
        GOTO TextIn2
DoneInput:
        Return
 
 
NoInput:
        ArrayWrite InputString,[REP 0\MaxChars]  ; wipe everything 
out
        hserout [CR,LF,"No Input!",CR,LF]
 
Return
 
 
;------------------------------------------------------------------------------
 
 
ConvertToUpper:
     For X = 0 to MaxChars
       IF InputString[X] > 96 and INputString[X] < 123 then
          InputString [X] = Inputstring[X] & %11011111
       ENDIF     
 
     Next X
 
     Return
 
 
;-----------------------------------------------------------------------------
 
 
Parseit:
 
Parse01: Cmd=01 : ARRAYREAD InputString,InputString_Len,Parse02,[WAIT("AGE")] : GOTO Foundit
Parse02: Cmd=02 : ARRAYREAD InputString,InputString_Len,Parse03,[WAIT("BIRTHDAY")] : GOTO Foundit
Parse03: Cmd=03 : ARRAYREAD InputString,InputString_Len,Parse04,[WAIT("CITY")] : GOTO Foundit
Parse04: Cmd=04 : ARRAYREAD InputString,InputString_Len,Parse05,[WAIT("STATE")] : GOTO Foundit
Parse05: Cmd=05 : ARRAYREAD InputString,InputString_Len,Parse06,[WAIT("COUNTRY")] : GOTO Foundit
Parse06: 
Cmd=255
 
 
 
Foundit:
 
 
  Select Case Cmd
      Case 1
        Hserout [CR,LF,"You typed 'AGE'",CR,Lf]
      CASE 2
        Hserout [CR,LF,"You typed 'BIRTHDAY'",CR,Lf]
      CASE 3
        HSEROUT [CR,LF,"You typed 'CITY'",CR,Lf]
      CASE 4
        HSEROUT [CR,LF,"You typed 'STATE'",CR,Lf]
      CASE 5
        HSEROUT [CR,LF,"You typed 'COUNTRY'",CR,Lf]
      CASE ELSE
        HSEROUT [CR,LF,"Invalid command",CR,LF]
   END SELECT
 
 
RETURN
    This article was originally published in forum thread: Input routine and command parser started by Charles Linquis View original post