Questions tagged [printf]
10 questions
3
votes
1 answer
Using pointers with Arduino
I am learning about pointers.
I was wondering how the memory address is defined in programming. I get different outputs depending on the format I choose for memory address. So I was wondering if it is correct to assume that the format of the memory…
Jack
- 143
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3
votes
1 answer
How to use printf with Arduino's serial ports without an intermediary buffer?
How to use printf with Arduino's streams without an intermediary buffer? The following seems unnecessary:
char buf[256];
sprintf(buf, ...);
Serial.print(buf);
Is there a way to connect HardwareSerial or SoftwareSerial to a libc stream or is there a…
Ana
- 470
- 2
- 7
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1
vote
1 answer
How to use a variable format in `sprintf`
How should I make a variable format sequence for sprintf?.
int i=2,d=9;
String sf;
sprintf(sf,"%%0%d",i);
fprintf(sf,d);
While expecting the output.
09
The compilation fails, with several errors, according the failing change I apply.
Invalid cast…
Brethlosze
- 333
- 3
- 17
1
vote
2 answers
Porting the FastNoise c++ library to Due
I'm trying to use the FastNoise library with a Due, however, I get something like the following errors, when I try to complie.
error: 'abs' was not declared in this scope
error: 'mt19937' is not a member of 'std'
error: 'uniform_int_distribution' is…
Gergo
- 13
- 2
1
vote
3 answers
formatting of IPAddress via printf(...) family similar to Serial Object
I am trying to use an sprintf with an IPAddress and I am not sure why Serial.print() is able to convert IPAddress to a reasonable human readable representation. I mean, presumably it uses an overloaded function that detects what type the parameter…
Octopus
- 150
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- 8
0
votes
1 answer
printf %s gives gibberish
This Code:
String S0 = "";
String S1 = "1";
String S2 = "12";
String S3 = "123";
String S4 = "1234";
String S5 = "12345";
String S6 = "123456";
String S7 = "1234567";
String S8 = "12345678";
String S9 = "123456789";
String S10 = "1234567890";
String…
AKTanara
- 163
- 5
0
votes
2 answers
Strange behavior from uint32_t, acting like signed int (Nano clone)
I'm having trouble with these variables. As you can see they're uint32_t type, so they should have a maximum value of 4 million or so, but they're rolling over and going negative at 32,767 like a signed int. Here's the relevant code:
byte lPin =…
HaLo2FrEeEk
- 103
- 3
0
votes
1 answer
Serial printf implementation
Based on this approach I wanted to implement a function for formatted printing data to the serial monitor. I tried the code below:
int PIN = 12;
void _printf(char *fmt, ...) {
va_list va;
va_start(va, fmt);
char buf[vsnprintf(NULL, 0, fmt,…
pt12lol
- 101
- 1
- 3
0
votes
2 answers
Using the Logging library, sometimes doesn't exit setup()
This has been a hard problem to diagnose, so I hope I'm giving enough info here. I'm trying to write a program for the Arduino (a lighting controller) using a bit of OO. There are several classes in my library, and some extend others. I'm a…
dj_segfault
- 137
- 8
0
votes
1 answer
AVR has no vprintf_P?
Well this was unexpected. AVR libc has many the variants of printf, including vprintf, but is missing vprintf_P. Is this really just not present or implemented elsewhere?
Ana
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