Hard Task in need of assistance

rawr · 2004-12-02 05:57

My robot will have three pushbuttons and three LEDs; red, yellow, and green.· My program will make my robot go fast and have a green LED go on, when the go button is pressed.· It will continue to do this task until another button is pressed.· My robot will go slower when the yellow button is pressed.· It will continue to do this task until another button is pressed.·

My Question is what commands do i use... if else, if than, else?

Please help me get my program off the drawing board.

·

Jon Williams · 2004-12-02 11:57

Give this idea a try; it uses a subroutine to scan and debouce all three buttons and will only change operational modes when a single button is pressed.

Main: 
  DO 
    GOSUB Scan_Buttons 
    IF (buttons > 0) THEN 
      temp = $F 
      LOOKDOWN buttons, [noparse][[/noparse]%001, %010, %100], temp 
      IF (temp <> $F) THEN mode = temp 
    ENDIF 

    ON mode GOSUB Mode_0, Mode_1, Mode_2 
  LOOP 


Mode_0: 
  GreenLed = On
  YellowLed = Off
  RedLed = Off
  RETURN 


Mode_1: 
  GreenLed = Off
  YellowLed = On
  RedLed = Off
  RETURN 


Mode_2: 
  GreenLed = Off
  YellowLed = Off
  RedLed = On
  RETURN
 
 
Scan_Buttons: 
  buttons = %0111                ' assume pressed 
  FOR idx = 1 TO 4               ' debounce for 20 mS 
    buttons = buttons & ~INA     ' active-low inputs on INA 
    PAUSE 5 
  NEXT 
  RETURN

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Jon Williams
Applications Engineer, Parallax
Dallas Office

rawr · 2004-12-03 09:48

thank you

rawr · 2004-12-07 11:29

hey, i'm going to add another function in this program.· I'm going to add something that makes the robot stop when a push button is pressed.

Main:
· DO
··· GOSUB Scan_Buttons
··· IF (buttons > 0) THEN
···· ·temp = $F
···· ·LOOKDOWN buttons, [noparse][[/noparse]%001, %010, %100], temp
···· ·IF (temp <> $F) THEN mode = temp
··· ENDIF

··· ON mode GOSUB Mode_0, Mode_1, Mode_2
· LOOP

Mode_0:
··GreenLed = On
· YellowLed = Off
··RedLed = Off
· RETURN

Mode_1:
··GreenLed =·Off
· YellowLed = On
··RedLed = Off
· RETURN

Mode_2:
··GreenLed =·Off
· YellowLed = Off
··RedLed = On
· RETURN

Scan_Buttons:
· buttons = %0111··············· ' assume pressed
· FOR idx = 1 TO·4·············· ' debounce for 20 mS
··· buttons = buttons & ~INA···· ' active-low inputs on INA
··· PAUSE 5
· NEXT
· RETURN

that's the program you gave me.· How will I add a Mode_3?

nick bernard · 2004-12-07 14:17

Main:
DO
GOSUB Scan_Buttons
IF (buttons > 0) THEN
temp = $F
LOOKDOWN buttons, [noparse][[/noparse]%001, %010, %100,%1000], temp
IF (temp <> $F) THEN mode = temp
ENDIF

ON mode GOSUB Mode_0, Mode_1, Mode_2, Mode_3
LOOP

Mode_0:
GreenLed = On
YellowLed = Off
RedLed = Off
RETURN

Mode_1:
GreenLed = Off
YellowLed = On
RedLed = Off
RETURN

Mode_2:
GreenLed = Off
YellowLed = Off
RedLed = On
RETURN

Mode_3:
GreenLed = Off
YellowLed = Off
RedLed = Off
RETURN

Scan_Buttons:
buttons = %1111 ' assume pressed
FOR idx = 1 TO 4 ' debounce for 20 mS
buttons = buttons & ~INA ' active-low inputs on INA
PAUSE 5
NEXT
RETURN

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League Bowling.... it's not a sport, it's a way of life

Post Edited (nick bernard) : 12/7/2004 2:20:30 PM GMT

nick bernard · 2004-12-07 14:21

something like that?

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League Bowling.... it's not a sport, it's a way of life

rawr · 2004-12-10 02:49

'{$STAMP BS2}
'{$PBASIC 2.5}

red VAR IN0
yellow VAR IN3
green VAR IN6
crash VAR IN9
counter VAR Word

Main:
DO
GOSUB Scan_Buttons
IF (buttons > 0) THEN
temp = $F
LOOKDOWN buttons, [noparse][[/noparse]%001, %010, %100,%1000], temp
IF (temp <> $F) THEN mode = temp
ENDIF

ON mode GOSUB Green, Yellow, Red, Crash
LOOP

Green:
HIGH 6
DEBUG "Green", CR

FOR COUNTER = 1 TO 375
PULSOUT 15, 50
PULSOUT 14, 1500
NEXT
RETURN

Yellow:
HIGH 3
DEBUG "Yellow", CR

FOR COUNTER = 1 TO 375
PULSOUT 15, 50
NEXT
RETURN

Red:
DEBUG "Red", CR
STOP
RETURN

Crash:
DEBUG "Crash", CR: FREQOUT 9, 1000, 1568
RETURN

Scan_Buttons:
buttons = %1111 ' assume pressed
FOR idx = 1 TO 4 ' debounce for 20 mS
buttons = buttons & ~INA ' active-low inputs on INA
PAUSE 5
NEXT
RETURN

how come buttons is an unidentified symbol??? plz resond quickly.

Bruce Bates · 2004-12-10 09:12

rawr -

The simple and obvious answer as to why it's being flagged as undefined, is that it wasn't defined before it was used. It's customary to define all the variables and constants that you are going to use in your program at or near the beginning of your program. Adding the following definition will eliminate that particular errror, but there are many others in the program:

buttons· var· ·nib· 'allocate 4 bits of RAM for button state

Just as an observation a good deal was changed in this program from when Jon originally supplied it. Notable among the changes which are about to cause you trouble, are the changes below (as examples):

Former····· Latter········· Comment

······

··········

redled··· -> red····redled was unique, red now defined both as var name + program label

greenled-> green· greenled was unique, green now defined both as var name + program label.

Other changes similar to those were also made. You may want to just go back to the original program that Jon provided,·and make your changes again. A good deal was lost in the last alteration process.

Regards,

Bruce Bates

Hard Task in need of assistance

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