Input routine and command parser

[Charles Linquis]

This should probably be moved to the 'Examples' section, but I'll post it here for awhile so it will get noticed.

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.

Enjoy.



'************************************************* ***************
;
;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

[mackrackit]

Thanks Charles,

Would you happen to have a schematic to go with this? Looks like it would make a good article for the projects section.

[Charles Linquis]

Not really. It does run on hardware, of course, but that hardware is really proprietary. But no hardware is needed for this. 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.

I figured that lots of people use things like this (or maybe I'm the only one). At any rate, I use similar routines a lot. They are modified to protect the innocent, and the copyright property of the company I work for.

[ivanrosales]

Thanks for sharing "Master" Charles, this code is very useful indeed, in fact should be great to see this sort of capabilities bundled with PBP.
I'll try it in the first chance...

Regards!