>>
My question is: how can I modify my subroutine so that I can set which pin
to oscillate. I want to be able to do something like:

movlw     1; load w with number of pin on porta to pulse
call    ping; oscillate pin 1
movlw    2;now load in new pin number
call    ping ;    oscillate pin 2.

How can I do this? Are instructions like BCF porta,w valid?
<<

No, the bit number in BCF and BSF are hard coded into the instruction, so you
can't do it that way.  You can set up a mask with the selected bit set to
one, then OR with the mask to enable the bit and AND with the inverted mask
to disable the bit.


********************************************************************
Olin Lathrop, embedded systems consultant in Littleton Massachusetts
(978) 742-9014, olin@embedinc.com, http://www.embedinc.com

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