17
votes
Accepted
_delay_ms() is much slower than expected (by a factor of 6) on TinyAVR 0/1 (ATTiny1604)
Your toolchain is not broken. In the ATTiny804/1604 datasheet, page 77, it shows the CPU clock is divided from the 20/16 MHz oscillator by a prescaler (the ATTiny1614 datasheet shows the same clock ...
- 439
5
votes
Accepted
MEGA 2560: Simple program - One analogWrite turns off the other
As you are using using ArduinoIDE >=1.8.10 its an "optimization" problem by the compiler for the Mega try to replace the line
void setup()
with
void setup() __attribute__((optimize("-O0")));
...
- 1,331
5
votes
Accepted
Porting code from Arduino IDE to other IDEs - expected code size reduction
You don't need to abandon the Arduino IDE.
Let me quote from my forum post about sketch sizes.
Introduction
Every now and again this subject pops up on the Arduino forum. Why does it take 1000 ...
- 38.7k
5
votes
Equivalent to POSIX mmap() in AVR-libc
No.
First, mmap() makes almost no sense on an AVR, as there's no memory management unit or concept of process memory to configure. Some related concepts like sbrk() are occasionally implemented in a ...
- 5,401
3
votes
Accepted
Interleave disassembly + source with avr-objdump
The .stabs section contains debugging info, not actual code. There is no
point in trying to “disassemble” it. The -D option of avr-objdump
means “disassemble everything, whether or not you believe it'...
- 44.3k
3
votes
Accepted
AVR-GCC can't call function located on fixed address
I've tried this code with arduino and it worked (i taught, of course, i can't add the "-Wl,--section-start=.app_start=0xFA0" flag to the compilation process so the function not gonna be moved to other ...
- 193
2
votes
Accepted
programming arduino in pure c
In file included from led.c:3:0:
/usr/lib/avr/include/util/delay.h:95:3: warning: #warning "Compiler
optimizations disabled; functions from won't work as designed"
You should start by fixing this....
- 44.3k
2
votes
Can I port a project built on Arduino Uno to a standalone ATmega328 using the exact same code?
Almost all of my projects are roll-your-own-duinos with Atmega 328p chips, with code generated for an "Arduino/Genuino Uno" board. Many of them use an ESP8266-01 board as a WiFi interface. I either ...
- 15.3k
2
votes
Accepted
avr-gcc -D is ignored
You are using $(CPPFLAGS) for *.cpp files but only $(CXXFLAGS) are defined.
This should be obvious from command line (if you enable showing executed commands for make)
And also:
CC =
using $(CPP) ...
- 4,777
2
votes
How would I include Arduino libraries using AVR-gcc without the IDE?
Since you will end up using a significant portion of the Arduino core
library, the easiest path is to accept the idea that you are now writing
“Arduino sketches” rather than plain C++ code. Don't ...
- 44.3k
2
votes
Porting code from Arduino IDE to other IDEs - expected code size reduction
If you like the Arduino IDE, you also can do the following:
Do not use the library functions, but use registers directly.
The compiler is smart enough that it does not link functions you do not use ...
- 13k
2
votes
Multiple defintion error, Linker error
You forgot the -c flag to your first command. That means you have first compiled your program into a full elf file. Then you try to link that elf file with the standard startup libraries again (it ...
- 106k
2
votes
Accepted
ISR definition causing boot loop?
Your problem is not with your code. It's with how you're linking your elf file.
You haven't specified the chip to link for.
$ avr-gcc -mmcu=atmega328p boot_loop.o -o boot_loop.elf
- 106k
2
votes
Accepted
What else is consuming Data Segment reported by avr-size?
Most of the missing data section is probably made of string literals.
When you write something like
Serial.println("Hello, World!");
the string "Hello, World!" is implemented by ...
- 44.3k
2
votes
Accepted
What's Memory Allocation technique in Arduino
Use the source, Luke!
The AVR-based Arduinos rely on the avr-libc library, which provides
malloc() and friends. You can read the source code online.
It is generously commented, and you can understand ...
- 44.3k
2
votes
Accepted
How do I build and upload a C++ program without the Arduino Library or IDE?
Create a new file called Makefile in your project directory. Populate it with the following contents:
TEMPDIR := $(shell mktemp -d)
all:
avr-g++ -DF_CPU=<CLK> -mmcu=<PARTNO> -fno-...
- 317
2
votes
Accepted
AVRdude does not read the FUSE byte values correctly
A couple of things. That you can't change fuses from the bootloader and that optiboot can't report fuse values correctly, even if you change them.
No self-programming of fuses
A bootloader can't ...
- 5,414
2
votes
What happens when you call malloc()/free()/new/delete?
There are some hardware-specific abstractions (they mostly define the maximum memory available), but otherwise these are functions are implemented by the C/C++ runtime (on arduinos an implementation ...
- 1,306
1
vote
What's Memory Allocation technique in Arduino
Long answer short, it used both first-fit and best-fit.
The malloc function in the avr-libc makes use of a so-called free list to track the free spaces in the memory.
When there is a memory request, ...
- 111
1
vote
Accepted
Why is Toolchain Not Updated with Arduino IDE Install on Mac
The boards packages maintained by Boards Manager and associated tools are installed in .arduino15 folder. The AVR boards package bundled with IDE is only used when there is no AVR boards package ...
- 18.2k
1
vote
Accepted
My software serial code won't work at > 4800bps
At 1MHz and 9600 baud, you have a total of 104 clock cycles available to run your interrupt routine in. A quick count up of the assembly instructions generated comes to more than that (around 126 at ...
- 106k
1
vote
Accepted
avr_g++ compiler error: expected primary-expression before '.' token (C code in .ino)
.ino is compiled as C++. your test is C code. put the C code in a .c file and the declaration in .h file and include the .h in .ino
I created a test.c, copied the content of your main.c into it and ...
- 18.2k
1
vote
avr/io.h No such file or directory error when compiling using avr-gcc
I’m guessing you started with the toolchain Arduino put on your machine.
Try explicitly including the header files on the include path with the -I switch.
avr-gcc -mmcu=atmega328p -I /path/to/avr/...
- 332
1
vote
Porting code from Arduino IDE to other IDEs - expected code size reduction
I have managed some 33% downsizing, hurrah!
Adding to the current answers: the biggest reduction came by ridding the floating points. I have come across the answer here and put avr-objdump to good ...
- 137
1
vote
Accepted
Compiling source with Arduino.h with avr-g++
You need to do a whole lot more than just run the one command.
You need to compile each individual source file for the libraries you want (using -c to just compile and not link), then (ideally) ...
- 106k
Only top scored, non community-wiki answers of a minimum length are eligible