How to use invert bit in define command by macro

[huynhhai]

Hi Everyone,

I had one a hardware, now i want to write code to use it, (my PIC16F886)
in the define line: #define led PIN_C5


the code in my program:

output_high(led); --> PIN_C5 will come 1

my question:
output_high(led); --> PIN_C5 will come 0, it mean PIN_C5 will be invert bit from 1 to 0

OR output_low(led); --> PIN_C5 =1??

how i change #define led PIN_C5 ??

Please help me about them.

Regarsd
huynhhai

[temtronic]

output_high means the pin will set high (+3 or +5), whatever VDD is
output_low means the pin will set low (zero)

As to whether a high turns on the LED, depends on how the LED and it's resistor are wired.
If the Anode of the LED is on the port_pin and it's resistor tied to ground, then a high will turn on the LED.

[PCM programmer]

I'm not sure what you want, but look at output_toggle() to invert a pin.

[huynhhai]

I can use macro to write code on command #define such as output_toggle(),

Regards

[Ttelmah]

Key here is the concept of 'reserved words'. No, you cannot change the
meaning of a reserved word with a macro. Output_high and output_low
are reserved words. If you did change these, it would make every library
not work, etc. etc.
Use your own keyword. So:

[huynhhai]

Thank you very much for you help, i solved it by changed code in programs (changed library).

Regards,
huynhhai

[PrinceNai]

I'm sure it works. For now. And only for you. If you update the compiler, those libraries will be overwritten. If you have a copy in your project folder, you'll have two different libraries with the same name doing opposite things. The way all the other guys told you to do it is for a reason. Many reasons, actually. Who on earth would think that output_low actually sets the bit? That is why the function name is output_low. It outputs low. You wouldn't code a start() function to stop something :-)

[temtronic]

re: