# Open Hardware for Renewable Energy

The vision behind Libre Solar is to develop open-source hardware components for a smart and renewable energy system.

# Development stage badges

Currently, different versions of charge controllers and battery management systems (BMS) are under development. The development stage of the devices is marked with the following badges:

Development Stage Very early development stage, major issues expected.

Development Stage Prototype built, development ongoing (major issues might still be open).

Development Stage Tested prototype, only minor issues left. Development board might be available.

Development Stage Device ready for production.

Unless stated otherwise, none of the published devices has passed regulatory certification, so use them at your own risk and responsibility (see also CC-BY-SA licenseopen in new window).

We are offering some of the devices as a development kit to make participation in the ongoing development easier. Releases of fully certified products are also planned for the future. For all other hardware you will have to order parts and assemble the device yourself.

# Versioning

The versioning for hardware follows the scheme major.minor[.revision].

The major version is only increased for a complete redesign or significant changes of features. During initial development phase, the major version is 0. The first released hardware that goes into production gets version 1.0.

If small features are added or changed, or pin assignment of the MCU is updated, the minor version number is increased. A change in the minor version might require changes in the firmware.

The revision number is optional and should identify small changes, especially bug fixes. The firmware must be compatible with the previous revision of the same minor version, so no pin or resistor divider changes are allowed.