Astarte non volatile storage example

This example will guide you through setting up a simple ESP32 application running the Astarte SDK configured to use an NVS partition for persistent storage.

This example will perform the device registration starting from a provided JWT token.

Partition table

The partition table used by this example is contained in partitions_example.csv. The only change from a regarding the SDK from a standard basic table is the addition of the astarte partition.

Note that this table contains two NVS partitions. A generic nvs labelled partition and the astarte labelled partition. The nvs partition can be used by some ESP drivers such as the WIFI driver. We suggest creating a separate partition for the SDK data not to be shared with other components. This will prevent issues related memory sharing.

Note that the astarte partition minimum size is not determined by the SDK memory requirements but by the minimum NVS partition sizes. Data partitions of NVS type are recommended to have a size of at least 12kB (0x3000) due to some NVS library limitations.

Enabling NVS in the example

The following two lines of code are sufficient to instruct the SDK to use the NVS partition specified.

nvs_flash_init_partition("astarte");
astarte_credentials_use_nvs_storage("astarte");

Make sure you call astarte_credentials_use_nvs_storage before calling any other credentials related funcion.