Questions tagged [c-preprocessor]
the macro preprocessor for the C and C++ computer programming languages.
16 questions
23
votes
4
answers
19k
views
List of Arduino board preprocessor #defines
When one selects a board within Arduino IDE, a preprocessor definition is added to one of the behind-the-scenes files.
After a lot of hunting and some good fortune I found that the format of this ...
CommunityBot
- 1
3
votes
2
answers
2k
views
is #ifdef __SD_H__ considered a bad practice?
Say I'm working on a library^1 to which I want to add support for SD.h^2 but knowing for a fact that many microcotrollers don't support SD.h (therefore they result in compilation errors [eg. Attiny85])...
- 38.9k
-1
votes
1
answer
172
views
Char Array in PreProcessor
I need to define an array, that later on will be the name of a class, and will be pointed to.
For example (in a non pre-processor way):
const char *button_names[4]={"b0","b1","...
CommunityBot
- 1
-1
votes
1
answer
73
views
Unable to get my created library to work - while it compiles
I am experimenting with creating my own Arduino libraries. Unfortunately, while the program compiles, the end result does not work.
For purposes of experimentation, I have broken down the library in ...
- 18.3k
1
vote
0
answers
54
views
How initialise and uninitialise serial based on the user's input?
In Summary. If the argument is true, I want to create a function that prints the necessary stuff into the serial. However, if its false serial is uninitialised and does not print anything, it only ...
CommunityBot
- 1
0
votes
1
answer
171
views
#define from main (.ino) not considered by comiler in own libaries
I have got the problem, that my #define from main (.ino) is not considered by the comiler in my own libaries. This #define MQTT_MODULE is only considered in the main (.ino) programm, but not in ...
- 45.2k
0
votes
2
answers
241
views
Odd behavior of defines - is this Arduino specific and how does it work?
A question I have long had regards an interaction between #define statements and a library header include. I've seen several Arduino libraries use this rather convenient configuration system where you ...
- 15.4k
0
votes
1
answer
99
views
A strange bug in my Arduino ALU
I have discovered a strange error in my Arduino. It's not in the code. I think it's a hardware bug in the ALU of the microcontroller, maybe in clone only.
So there is a variable called feedLimit and ...
- 106k
0
votes
4
answers
158
views
How to link a computer processor to an Arduinno on a board? [closed]
I am completely new to Arduinno, so please forgive if the question is stupid.
Here is the problem: I have a project where I want an Arduino (or similar microchip board) to handle some sensors and ...
- 106k
1
vote
1
answer
305
views
#define above static const int?
I see a lot of people, but also libraries, defining constants (like pin numbers, length of items etc) as #define:
#define LENGTH 5
While it is recommended to use in this case static const int:
...
- 106k
2
votes
1
answer
258
views
Remove Function at Preprocessor Time
I have a single function for debugging messages, used through all the project. When KEYDEBUG is defined as 1 or 0, the function is enabled or disabled as required.
#define KEYDEBUG 0
void debugging(...
- 2,514
6
votes
2
answers
2k
views
Detect if Serial1 and Serial2 are defined, at compile time
I have my library that uses Serial, Serial1 and Serial2 to establish various logging scenarios. Library user would define the config at class constructor, using simple byte constants like 0, 1 and 2.
...
- 18.3k
0
votes
1
answer
144
views
Segmentation fault and huge SRAM need for Serial.println
I have written my own 'assert' since I want to use it for both Windows and Arduino. The class is called from many files (about 10).
AssertUtils.h:
#pragma once
#define assert(expr) AssertUtils::...
- 13k
24
votes
4
answers
5k
views
Why use an int variable for a pin when const int, enum or #define makes much more sense
Why do people use a variable to specify a pin number when the pin is unlikely to change throughout the execution of the code?
Many times I see an int being used for a pin definition,
int led = 13;
...
- 106k
2
votes
1
answer
417
views
Syntax of binary Constants
I was trying to compile some Arduino code on the PC for testing when I noticed some strange syntax for numerical binary constants.
Convetion seems to be to declare them like so:
static const ...
- 106k