How to access Project Name and compile Date/Time as variables within the code?

#1

Hi All,
How can I have a constant/variable that has the project name and compiled date/time accessible within the project?

Example
#define COMPILED $UNIX_TIME // or similar
#define PROJECTNAME $folder // or similar

printf(“Project compiled at %s/n”,COMPILED);
printf(“Project Name at %s/n”,PROJECTNAME);

Thanks,
Neil

#2

As the documentation shows, you can inject the Unix time into the build system by writing

build_flags =
   -D CURRENT_TIME=$UNIX_TIME

You can use this timestamp to convert it into a human readable time.

Alternatively and way more easier, use the __DATE__ and __TIME__ built-in macros that are compiler-defined and are already strings (https://www.cprogramming.com/reference/preprocessor/DATE.html).

While the project name isn’t directly available, you can pass in $PROJECT_DIR (string escaped) to get the full ptath to the projects, e.g., C:\Users\Max\temp\atmega4809.

#3

Hi and thanks for the quick reply.

I don’t understand how to use $PROJECT_DIR
I tried
[env]
build_flags =
-D NEIL=27
-D PROJECT_NAME=$PROJECT_DIR

But this just gives me strange errors.

#4

Yeah the $PROJECT_DIR is tricky because it is a string and it contains characters that need to be escaped, such as backslashes. You need to use scripting to convert that to an acceptible compiler argument for -D.

The following is a minimal example:

[env:uno]
platform = atmelavr
board = uno
framework = arduino
build_flags =
   -DCOMPILE_UNIX_TIME=$UNIX_TIME
extra_scripts = pre:inject_path.py

with
inject_path.py being on the same directory level as platformio.ini

Import("env")
proj_path = env["PROJECT_DIR"]
proj_path = proj_path.replace("\\", "\\\\")

macro_value = "\\\"" + proj_path + "\\\""

env.Append(CPPDEFINES=[
  ("PROJECT_PATH", macro_value)
])

and src\main.cpp

#include <Arduino.h>

void setup() {
   Serial.begin(9600);
}

void loop() {
   Serial.print("PlatformIO Unix compile time: ");
   Serial.println(COMPILE_UNIX_TIME);
   Serial.print("Project directory: ");
   Serial.println(PROJECT_PATH);
   Serial.print("__DATE__: ");
   Serial.println(__DATE__);
   Serial.print("__TIME__: ");
   Serial.println(__TIME__);
   delay(2000);
}

gives output

>pio run -t upload -t monitor
[...]
--- Miniterm on COM3  9600,8,N,1 ---
--- Quit: Ctrl+C | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
PlatformIO Unix compile time: 1640016119
Project directory: C:\Users\Max\temp\time
__DATE__: Dec 20 2021
__TIME__: 17:02:00
1 Like
#5

Fantastic.
Many Thanks.