# Creating Unique Factory Data Images

DevFeed: [Creating Unique Factory Data Images](<https://devfeed.tech/articles/creating-unique-factory-data-images-13827.md>)

Original publisher: [Read original article](<https://developer.espressif.com/blog/creating-unique-factory-data-images/>)

Author: John Lee

Published: 2018-05-01T00:00:00Z

Content type: tutorial

Language: en

Sources: [Blog on Developer Portal](<https://devfeed.tech/sources/blog-on-developer-portal.md>)

Topics: [ESP-IDF](<https://devfeed.tech/topics/esp-idf.md>), [Embedded Software Dev](<https://devfeed.tech/topics/embedded-software-dev.md>), [configuration](<https://devfeed.tech/topics/configuration.md>)

Tags: [blog](<https://devfeed.tech/tags/blog.md>), [building-products](<https://devfeed.tech/tags/building-products.md>), [configuration](<https://devfeed.tech/tags/configuration.md>), [esp](<https://devfeed.tech/tags/esp.md>), [esp-idf](<https://devfeed.tech/tags/esp-idf.md>), [firmware](<https://devfeed.tech/tags/firmware.md>), [homekit](<https://devfeed.tech/tags/homekit.md>), [manufacturing](<https://devfeed.tech/tags/manufacturing.md>), [partition](<https://devfeed.tech/tags/partition.md>), [password](<https://devfeed.tech/tags/password.md>), [wi-fi](<https://devfeed.tech/tags/wi-fi.md>)

## AI overview

This tutorial explains how to use multiple NVS partitions in ESP-IDF to store per-device factory data separately from user configuration. It describes creating unique partition images for manufacturing and preserving the ability to erase user settings during a factory reset.

## Source excerpt

A common requirement while building a device is to have some unique information programmed into the device at the time of manufacturing. This information could be a unique serial number, or a unique MAC address ; or it could be a unique secret like the default password, or the HomeKit pairing pin. We have seen quite a number of ways that customers have achieved this. - Some use a few NVS keys to store this information at the factory.