Charles R. Veres - 2015-06-05

The following code demonstrates how to set the weak pull-ups available on port b of an 18F25K20. It is for anyone who may be having trouble with this

' program tests use of weak pulled-ups on portb.
' tests good effective R pullup about 33 K ohms.
'Set chip model:
#chip 18F25k20,16 'at 16 MHz
'Switch Low-Volt-Programming:
#config LVP = Off
#config MCLR = Off

'Set internal clock speed to 16 MHz:
Set IRCF0 = 1
Set IRCF1 = 1
Set IRCF2 = 1

Set RBPU = 0 'enabling Port B pullups in general.
SET WPUB1 = 1 'portb.1 pulled up
Set WPUB2 = 1 'portb.2
Set WPUB3 = 1 'portb.3
Set WPUB4 = 1 'portb.4

Dir Portb in
Dir Portc out

do

Let portc.1 = portb.1 'in pin 22, out pin 12
Let portc.2 = portb.2 'in pin 23, out pin 13
Let portc.3 = portb.3 'in pin 24, out pin 14
Let portc.4 = portb.4 'in pin 25, out pin 15

loop 'jump back to the start of the program

'main line ends here
end