nvs-dotenv

nvs-dotenv is an ESP-IDF component which makes variables defined in a .env file accessible using getenv function:

Create a .env file inside you project directory
Keep various local configs and secrets in .env — Wi-Fi credentials, API tokens, and so on.
In your ESP-IDF application, call getenv function to access these variables

With nvs-dotenv, you won't have to:

hardcode credentials in your application source code
store the credentials in sdkconfig, and wait for the entire app to rebuild when you change them.

nvs-dotenv is intended to be used mainly during the development phase. In a production device you will likely need a provisioning workflow of some sort.

Using the component

In an existing ESP-IDF project, run the following command to install the component:
```
idf.py add-dependency "igrr/nvs-dotenv"
```

Edit your partition table, adding a new partition:

# Name,     Type,   SubType, Offset,  Size, Flags
dotenv,     data,   nvs,           ,  12k,

Create a .env file in your project directory:
```
WIFI_SSID=yyyyyy
WIFI_PASS=xxxxxx
```
In the application, initialize nvs-dotenv:
```
ESP_ERROR_CHECK(nvs_dotenv_load());
```
Now you can access variables from .env using getenv:
```
const char *ssid = getenv("WIFI_SSID");
```

Example

This component includes an example illustrating the above steps. You can try the example as follows:

idf.py create-project-from-example "igrr/nvs-dotenv:nvs-dotenv-example"

Then build as usual:

cd nvs-dotenv-example
idf.py build

And flash it to the board:

idf.py -p PORT flash monitor

The output should be:

I (3263) example: Loading environment variables
I (6033) example: WIFI_SSID: yyyyyy
I (6053) example: WIFI_PASS: xxxxxx

License

This component is provided under Apache 2.0 license, see LICENSE file for details.