Beginner Help with code

TonyA

I'm just starting to look at SPIN and working through the Propeller manual tutorial and am trying to complile and download this bit of code:

OBJ
  game_pad :  "gamepad_drv_001.spin"   'instantiating the gamepad driver object

PUB main
  game_pad.start                  'referencing the gamepad driver's start method
  game_pad.read                   'referencing the gamepad driver's read method
  
if (game_pad.button(NES0_UP)      'referencing the gamepad driver's button method. 
  DIRA[noparse][[/noparse]7]~~                       'If nes "up" button is pressed then make pin (7) an output
 
                                  'run the toggle loop.
Repeat
    !OUTA[noparse][[/noparse]7]                      'repeat the toggle process
    waitcnt(3_000_000 + cnt)      'timer
         

When I try to compile I get a message "Expected Expression" and NES0_UP is highlighted.

Could anyone offer advice?

Thanks in advance.





Post Edited (TonyA) : 7/3/2007 12:42:37 AM GMT

CardboardGuru

Unmatched brackets?

TonyA

Well, I thought that constants from the driver were also imported? (I'm a little confused)
When I added the CON block (see below), and then added another bracket;·(NES0_UP)), she complied.

CON
  NES0_UP     = %00000000_00001000 
 
OBJ
  game_pad :  "gamepad_drv_001.spin"   'instantiate the gamepad driver object

PUB main
  game_pad.start                  'driver's start method
  game_pad.read                   'driver's read method
  
if (game_pad.button(NES0_UP))     'driver's button method. 
  DIRA[noparse][[/noparse]7]~~                       {If nes up button is pressed then pin (7) is an output.}
                                  { run the toggle loop below.}
  Repeat
    !OUTA[noparse][[/noparse]7]                       'repeat the toggle process.
    waitcnt(3_000_000 + cnt)       'state of pin 7 with each pass through the loop.
    

Thanks.

Post Edited (TonyA) : 7/3/2007 1:34:27 AM GMT

CardboardGuru

You need to prefix the constant with the object name and a #.

So it's:

game_pad#NES0_UP

TonyA

I tried your suggestion; game_pad#NES0_UP and couldn't get it to compile.

I was going by this (in the comment of the gamepad_drv_001) where it says;

test if a specific button is down with:
' object_name.button(button_id)
' returns TRUE or FALSE

The button id is: NES0_UP

I'm just learning about OOP and programming (Outside of PBasic and PicBasic)·in general, but was wondering why I had to add the constant to the code of my top object when I am importing the driver?

Also, would this still compile if incorrect?
if (game_pad.button(NES0_UP)) 'driver's button method.

Thanks again.

Post Edited (TonyA) : 7/3/2007 2:29:33 AM GMT

CardboardGuru

TonyA said...
I tried your suggestion; game_pad#NES0_UP and couldn't get it to compile.

It does compile.

OBJ
  game_pad :  "gamepad_drv_001.spin"   'instantiating the gamepad driver object

PUB main
  game_pad.start                  'referencing the gamepad driver's start method
  game_pad.read                   'referencing the gamepad driver's read method
 
if (game_pad.button(game_pad#NES0_UP))      'referencing the gamepad driver's button method.
  DIRA[noparse][[/noparse]7]~~                       'If nes "up" button is pressed then make pin (7) an output
 
                                  'run the toggle loop.
Repeat
    !OUTA[noparse][[/noparse]7]                      'repeat the toggle process
    waitcnt(3_000_000 + cnt)      'timer

TonyA

Ok, I see now. I wasn't writing it that way. Still learning.

Thanks.