How can I do this (reversing high & low states depending on deployment & user need)

[gadelhas]

I probably do it like pedja089, but used the eeprom to save the setting!

[Darrel Taylor]

EE_Polarity DATA 0            ; Factory Default
SW1         VAR PORTB.0       ; Switch input pin
mosfet_gate VAR PORTB.1       ; mosfet output
Polarity    VAR BIT           

READ EE_Polarity, Polarity
IF !SW1 THEN WRITE EE_Polarity, !Polarity
READ EE_Polarity, Polarity

mosfet_gate = 1 ^ Polarity    ; Turn OFF
OUTPUT mosfet_gate
;----------------------------------------------

mosfet_gate = 0 ^ Polarity    ; Turn ON
mosfet_gate = 1 ^ Polarity    ; Turn OFF

[HankMcSpank]

Thanks to everyone...embarrasingly simple in the end! (hey, it was late!)

Hi Darrel, I was with you up to this bit....

EE_Polarity DATA 0            ; Factory Default
mosfet_gate = 1 ^ Polarity    ; Turn OFF
OUTPUT mosfet_gate
;----------------------------------------------

mosfet_gate = 0 ^ Polarity    ; Turn ON
mosfet_gate = 1 ^ Polarity    ; Turn OFF

Can anyone shed a little light on what's going on there (never used a ^ before!)

[pedja089]

That is XOR.
0^0=0
0^1=1
1^0=1
1^1=0
If Polarity is 1 or 0, depending on user settings. If Polarity is 0 then bit isn't inverted and result is same as:
mosfet_gate = 0 ; Turn ON
mosfet_gate = 1 ; Turn OFF
If Polarity is 1 then then bit are inverted so result is
mosfet_gate = 1 ; Turn ON
mosfet_gate = 0 ; Turn OFF