Nvm

A library for saving named strings into the EEPROM (non-volatile memory) of the ESP8266.

Introduction

The ESP8266 has an integrated non volatile memory (NVM). This library allows one to save and retrieve named strings into the NVM.

The following steps are required

• Define an nvm layout. This is a list of fields, and for each field the name, default value and length needs to be specified.
• Create and instance of the Nvm class. Pass the constructed layout.
• Save and retrieve data. Use the put and get methods.

Note, if a string is retrieved before it is stored, the default is returned. This is based on a simple checksum, which is also stored in the EEPROM.

Memory footprint is as follows: for each field, the EEPROM stores 1 byte (for the actual length), len bytes (for data, len as secified in the layout), 1 byte for the termination zero, and 1 byte a checksum.

Details

See Nvm.h for details.