Deployed a firmware image that doesn’t quite work? Made a mistake in development and don’t want to remove and reprogram the MicroSD card to go back? No problem. If the previous firmware image worked fine, then just revert back to it.

This is one of those features that has been possible since the beginning of the Nerves project, but we didn’t make it easy. That’s changing.

Most Elixir developers prefer Mac or Linux, but Windows is historically the platform of choice for embedded development. Therefore as Nerves continues to grow, a Windows solution is needed.

There are 2 fundamental approaches to Nerves-on-Windows:

1. Pretend it’s Unix
2. Run it as a Windows app

Unfortunately, there is no “silver bullet”–each approach has its trade-offs.

## January 2018 Nerves Update

Happy New Year from the Nerves team!

We’re marching ahead with our 1.0 plans and methodically going through our constituent projects to get them across the “finish” line. Work priorities have forced some Nerves development on tangents, but some of those may be of interest as well. Here’s a summary of what’s been happening:

## Using NIFs With Nerves

While working on a Nerves project, you will likely do most hard work in the host environment. This means you get to develop features quickly, and when are ready, you simply deploy your known working firmware to your embedded devices. This however can lead to a situation where the code runs really well on your i7 powered beast computer, but when deployed on a less powerful Raspberry Pi 0, for example. Nothing will be broken, but things are just too slow. There are a number of solutions to this problem and in this post, I will walk you through a simplified real world example of one possible solution of using an Erlang NIF to speed up one particular functionality.

## The Nerves Update

Wondering what’s happening on the Nerves project? You’re not alone. We’re planning semi-regular updates so that you don’t need to lurk on the elixir-lang Slack’s #nerves and #nerves-dev channels all the time.

Before the updates, I’d like to thank our Open Collective backers, Le Tote and FarmBot, since they’re majorly helping all of us make this project sustainable for the long term.

Alright, here are the highlights:

## Creating Patches Using Git

This is not an Elixir post, but it comes up when working with custom Nerves systems. The problem is how to deal with custom patches to Buildroot, Linux, or any of the non-Elixir libraries that your application might use. You may have seen patch files like these. These patch files are used to create local changes to projects when modifications either can’t be sent upstream (partial workarounds, hacks for specific systems, etc.) or haven’t been integrated yet. This post describes a way to create them.

## Using Ecto and Sqlite3 with Nerves

One of the most common questions we answer in the Nerves help channels is how to store persistant data across reboots. Since the file system is read-only, the normal avenues usually will not work with Nerves.

There are several solutions that have yielded varying levels of success accross projects. Before we dive too deep into SQLite, lets take a look at the other options:

## Using ASDF-vm

### Solve All of Your Version Problems

Nerves usually pushes the bleeding edge of Elixir, which means we sometimes sometimes hear about problems in our Nerves Slack channel that can be solved by updating to the latest version of Elixir and OTP. Now, there are built-in options in most operating systems to do this, such as brew, apt-get, pacman etc, and they all work with varying levels of success. ASDF-vm is an alternate version manager that allows easy installation and switching between different versions of various packages.