Junebug Tip & Trick #1, Using the DIP switch as a 4 bit mode switch

[blueroomelectronics]

Well it's beta but I always enjoy sharing ideas and always fun to have food for thought.
This code snippet will be in the next issue of JPUG but I thought I'd share it here for review.
It uses the debug pins and USART pins and I'll write a routine to show the status on the Junebugs LEDs.
It also depends on the 4.7K pulldowns on DIP switch switches 2,3,4,5 and the Junebug programmer normally floats PGC & PGD after programming.

        bcf     INTCON,RBIF     ; enable weak pullups on PORTB
GetDIP  movf    PORTB,W         ; DCxAxxBx 
        andlw   b'11010010'     ; DC0A00B0 (mask)
        btfsc   WREG,1          ; is B zero?       
        bsf     WREG,5          ; DCBA00B0
        swapf   WREG            ; 00B0DCBA
        andlw   0x0F            ; 0000DCBA

D = RB.7
C = RB.6
B = RB.1
A = RB.4

Note: one of the really neat features the 18F have over the 16F is W is also a register (WREG)...

 

[ericgibbs]

hi Bill,
Is that 'weak pull ups' on PORTB correct, should it be bcf INTCON2,RBPU

Tried with the new toy.
Hope you got the email OK.

Regards

 

[blueroomelectronics]

Thanks Eric, that one got past me. And yes I'm just reformatting your article for the next JPUG issue.
**broken link removed**