Hey, sorry if my terminology is not on point because I am not the most best with coding ect... I am trying to use:
void loop() {
// PORTD = 0xA-Left-Right-00000
// PORTB = 0x00-G-F-E-D-C-B
PORTD = B01000000;
goto left;
PORTD = B00100000;
goto right;
}
void left() {
PORTB = B00110011;
goto loop;
}
void right() {
PORTB = B00110011;
goto loop;
}
This code is for multiplexing two seven segment displays. The error I get it:
exit status 1
label 'left' used but not defined
Can someone explain how I'm meat to define these labels before the loop();?
system
March 9, 2016, 3:08pm
2
goto expects a label, and really has no place in your program
left() is a function, and should be CALLED:
left();
Okay, thank for the reply. I'm still not sure got to get my code working? Will my idea not work?
DrAzzy
March 9, 2016, 3:19pm
4
Rrplace the goto right and left with right() and left() and remove the "goto loop"
And you're setting PORTB to the same value in right and left, which I doubt is what you want
goto's should be avoided. Functions work as good and are easy to follow.
Just:
void loop() {
// PORTD = 0xA-Left-Right-00000
// PORTB = 0x00-G-F-E-D-C-B
PORTD = B01000000;
left();
PORTD = B00100000;
right();
}
void left() {
PORTB = B00110011;
}
void right() {
PORTB = B00110011;
}
But I have to say, now it will tell you things like B01000000 not defined... That's not the way to notate binary, 0b01000000 is
system
March 9, 2016, 3:23pm
6
septillion:
After adding
setup()
{
}
to the code in your reply, I get:
Binary sketch size: 480 bytes (of a 30,720 byte maximum)
So, clearly, B01000000 is defined.
Ah, you are right! :o Never knew Arduino/AVR-GCC accepted B as a binary prefix as well :o Learned something
system
March 9, 2016, 3:45pm
8
Never knew Arduino/AVR-GCC accepted B as a binary prefix as well
It doesn't, really. The Arduino.h file contains a bunch of #define statements that make it look like B01000000 is a real value, when it is really nothing more than some text that will be replaced by the preprocessor.
septillion:
It is really universal except that it is not standard C. It is a gccism. (Though it appears that that clang accepts it, too - I just tried)
0b apparently isn't universal C as well.... :
westfw
March 9, 2016, 7:43pm
11
0bXXXX is a gcc-ism.
Although I find 0b more universal