bit_test () or input () ?

GIO · Guest

Hello to all.

When I want to read if a button is pressed, is better to use:

#byte PORTB = 0x6
value = bit_test (portb,0)

or

value = input (PIN_B0)

???

Another question: using CCS bootloader, the only modify on my program is adding the line: #include <bootloader.h> , in all cases ?

Thank in advance, GIO

davekelly · Joined: 04 Oct 2006 Posts: 53 Location: Berkshire, England

For the bit test, I would go with the input (PIN_B0), which is portable if you change processors.

GIO · Guest

Thanks davekelly.

can I use value = input (pin) also for output pin , or in this case i sbetter to use value = bit_test (var, bit) ?

GIO

davekelly · Joined: 04 Oct 2006 Posts: 53 Location: Berkshire, England

Humberto · Posted: Tue Jan 09, 2007 8:12 am

1)value = bit_test (var, bit);

2)value = input (pin);

3)value = input_state (pin);

Basically generate the same code. Depending of the use of the standard I/O #use preprocessor.

As a general rule I use:

1) To test a bit in a variable only.
2) To get the level in the selected pin. This change the tris accordingly.
3) To know if the selected pin, is an Inp or Out, it can read the I/O state of the
selected pin without changing the tris.