Esp_now.h Not in PIO. It's ESP

I’ve used this program successfully. The library worked for me at some point.

esp_now.h

I can’t add it. It’s from the Espressif GitHub repository.
Does anyone have insight?

Can you give a direct reference to that esp_now.h file? Is it in the Arduino framework of the ESP8266 or ESP32?

Probably ESP32, it is present in both Arduino IDE and PlatformIO. If you can’t add it, you’re probably doing it wrong, or have broken your installation.

.platformio/packages/framework-arduinoespressif32/tools/sdk/include/esp32/esp_now.h
.arduino15/packages/esp32/hardware/esp32/1.0.4/tools/sdk/include/esp32/esp_now.h

ESP-NOW is not present on the ESP8266 Arduino core, but there is reference to a library for the ESP8266 in the documentation.

Minor change to the Basic Master ESP-NOW example (declaring functions so that it is valid C++ code) and it compiled just fine targeting the ESP32 dev board.

Hold on a second. I searched in the Libraries utility in PIO and in the registry on the PIO website.

Both have nothing.

How does that happen?

And how do I lib_deps it?

The addresses you share make no sense to me.
And the images make no sense either and are much to small to be read by a human. I guess you’re finding an esp_now folder somewhere.

The examples I copied direct from Random Nerds work.
I copied the lib_deps from the working program and it doesn’t work in my new file.

You don’t lib_deps it… esp-now is bundled with the ESP32 Arduino core… but not the ESP8266 core.

Open your file browser. Navigate to your home directory. Follow the remainder of the path…

Whilst the forum is being a bit odd with respect to those images (usually it shows a hand so you can click on them to get the full sized image), far be it from me to school you on how to use your web browser (right click on the images-view image to see it full sized)…

And which example is that?