Compile and import part of a library

1

Hello, I’m trying to use, due flash limits, a part of a library, pio seems to recognize the library dependency but it doesn’t compile the files i need.
I think this is not an automated process so, is there an easy way to do that?

N.B. What I’m trying to use is USI_TWI_Slave.c/USI_TWI_Slave.h part of wire library

2

Please state the full platformio.ini and code that fails.

3

Sorry, here it is:
.ini

; PlatformIO Project Configuration File
;
;   Build options: build flags, source filter
;   Upload options: custom upload port, speed and extra flags
;   Library options: dependencies, extra library storages
;   Advanced options: extra scripting
;
; Please visit documentation for the other options and examples
; https://docs.platformio.org/page/projectconf.html
[platformio]
default_envs = tests

[env:tests]
platform    = atmelavr
board       = attiny4313
framework   = arduino
build_flags = -g0 -Os -D DISABLEMILLIS

.cpp

#include <Arduino.h>
#include <USI_TWI_Slave\USI_TWI_Slave.h>

void setup(){
  USI_TWI_Slave_Initialise(0x3F);
}

void loop(){}

problem is a missing compiled file during linking stage

4

Is this file in the framework / arduino core or a library of the core? Or in a external library? (There are no lib_deps declarations)

5

Part of wire library

6

You’re including C prototypes (and functions implemented in C) in C++ code without using extern "C", which is wrong. Further you’re using Windows-style paths which will also only make the project compile under Windows – just use / on all systems.

Works for me.
platformio.ini

[platformio]
default_envs = tests

[env:tests]
platform    = atmelavr
board       = attiny4313
framework   = arduino
build_flags = -g0 -Os -D DISABLEMILLIS
lib_deps    = Wire

main.cpp

#include <Arduino.h>
extern "C"{
#include <USI_TWI_Slave/USI_TWI_Slave.h>
}
void setup(){
  USI_TWI_Slave_Initialise(0x3F);
}

void loop(){}
7

Yes, what a stupid, I think I’m a little bit “rusty” with c programming. Thanks again

1 Like