State machine with BS2

vaclav_sal · 2009-02-10 20:09

I am looking for a sample code written in Parallax basic implementing state machine.
I am·coding·four state system and just need something to get me started on my project.
Thanks for reading
·
·

Zoot · 2009-02-10 20:50



state VAR Nib
dur   VAR Byte

buttons VAR INA  ' active low buttons on pins 0-3
leds VAR OUTD ' 4 leds on pins 12-15

DIRA = %0000
DIRD = %1111

Start:

 state = $F
 dur = 255


Main:

Parse_Timer:
   IF dur > 0 THEN
      dur = dur - 1
   ENDIF
   PAUSE 100ms ' 100ms "frame" for state machine

Parse_States:

   ON state GOTO state_00, state_01, state_02, state_03 ' etc

state_04: ' and higher since they are not defined above -- waiting for "release"
  
   IF buttons = 0 THEN
      state = $0
   ENDIF
   GOTO States_Done

state_03:  ' wait for timeout, then see if no buttons pressed
    IF dur = 0 THEN
       state = $4
    ENDIF
   GOTO States_Done


state_02:  ' wait for button 3 to be pressed, if times out, restart state machine
    IF buttons.BIT3 = 1 THEN
      state = $3
      dur = 50 ' 5 seconds
    ELSEIF dur = 0 THEN
       state = $0 
    ENDIF
   GOTO States_Done

state_01:  ' wait for button 1 to be pressed, if times out, restart state machine
    IF buttons.BIT1 = 1 THEN
      state = $3
      dur = 50 ' 5 seconds
    ELSEIF dur = 0 THEN
       state = $0 
    ENDIF
   GOTO States_Done

state_00:  ' wait for button, if it's 0 or 3, then wait for  1 or 4 to be pressed within several seconds
    IF buttons = %0001 THEN ' won't work with simulataneous button presses
      state = $1
      dur = 20 ' user must press other button within 2 seconds!
    ELSEIF buttons = %0100 THEN
       state = $2 
       dur = 10 ' user must press other button within 1 seconds! fast!
    ENDIF
  '  GOTO States_Done


States_Done:
   leds = state ' show 4 bit state on leds
   DEBUG HOME, "state:", IHEX1 state, "    dur:",DEC3 dur, CLREOL
   ' more code, say outputting results of state machine actions

     GOTO Main

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When the going gets weird, the weird turn pro. -- HST

1uffakind.com/robots/povBitMapBuilder.php
1uffakind.com/robots/resistorLadder.php

Carl Hayes · 2009-02-10 21:32

Here's some.· It will take two replies to get it all in, but this machine uses multiple cogs -- no, not cogs, slots·-- and has many states.· It works. See the comments at the front for explanation of the states.

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· -- Carl, nn5i@arrl.net

Post Edited (Carl Hayes) : 2/10/2009 9:40:05 PM GMT

Carl Hayes · 2009-02-10 21:33

Here's the rest of it.· I have them a little out of order, because I left Slot 2 out of the first reply accidentally.

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· -- Carl, nn5i@arrl.net

Post Edited (Carl Hayes) : 2/10/2009 9:38:19 PM GMT

vaclav_sal · 2009-02-10 21:45

Thanks guys.

Tracy Allen · 2009-02-11 03:11

Hi vaclav_sal,

I have examples of PBASIC state machines posted at,
www.emesys.com/BS2fsm.htm
buttons, keypads, encoders, game. Good luck stamping!

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Tracy Allen
www.emesystems.com

State machine with BS2

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