Two PropBASIC questions....

JPTallman

I'm using PropBASIC with BST. Whenever I try to make a FOR...NEXT loop, it tells me that my variable (index, indx, idx, x, whatever I name it) is an "invalid parameter".

Also, I'd like to program on my MacBook Pro (I use my mom's laptop to program instead), but it can't find the port that I plug the Propeller into. When I try to choose a port manually, it does not come up with any ports.

Any help with either issue would be greatly appreciated. Thanks!!

JPTallman

DEVICE P8X32A, XTAL1, PLL16X
XIN 5_000_000

PROGRAM Start

Start:
FOR idx = 1 TO 10
TOGGLE 0
PAUSE 250
NEXT


GOTO Start

END


That's an example of what I'll code, and this is what it tells me:

GerryKeely

JPTallman wrote: »

DEVICE P8X32A, XTAL1, PLL16X
XIN 5_000_000
idx VAR LONG <========= add this line, you must declare idx as a variable
PROGRAM Start

Start:
FOR idx = 1 TO 10
TOGGLE 0
PAUSE 250
NEXT


GOTO Start

END


That's an example of what I'll code, and this is what it tells me:

JPTallman

Thank you!

Oh! Another thing I was wondering. Is there any way to do PWM commands using PropBASIC? I know that you can with BS2, but I haven't found the command in PropBASIC.

simonl

There is a PULSOUT command, so I guess that could be used with a loop?

Bean

PWM is best created using the hardware counters.
Here is an example using an LED on pin 15 (change for your setup).

' PWM Example
DEVICE P8X32A,XTAL1,PLL16X
FREQ 80_000_000

LED PIN 15 OUTPUT

i    VAR LONG
temp VAR LONG

PROGRAM Main

Main:
  COUNTERA 48, LED ' 48=DUTY mode
  DO
    FOR i = 0 TO 255
      temp = i << 24 ' Scale up to 32 bits
      FRQA = temp
      PAUSE 10
    NEXT 
  LOOP  
END

Bean

JPTallman

Is there a way to do this with multiple pins simultaneously?

Bean

JPTallman wrote: »

Is there a way to do this with multiple pins simultaneously?

Each cog has two counters (countera and counterb) so for two pins just use countera for one and counterb for the other.

For more than two pins, you need to make additional TASKs to do it with the hardware counters. Let me know if you need more than two and I experiment with it.

Bean

JPTallman

The goal is to be able to use all 24 pins I've got hooked up to LED channels. Thanks for your all your help!!

Mike Green

You could translate this Spin / Assembly PWM driver from the ObEx to PropBasic. It's mostly assembly so you could just copy that.