Replacing ISY with Home Assistant – Part 2 – A New Home

This is the continuation of a short series on transitioning away from the ISY using Home Assistant.

Getting Started, again

As I mentioned in my previous post, my plan is to run my new instance of Home Assistant in parallel with my old instance and transfer functionality in pieces. This should allow me to minimize downtime, and through the magic of reverse proxy, I will end up with the new instance living at the same URL as the old instance.

Part of the challenge of getting started is simply getting the Raspberry Pi setup in my desired configuration. I bought an Argon One M.2 case and an M.2 SSD card to avoid running Home Assistant on an SD Card. However, that requires a bit of prework, particularly for my older Pi.

New Use, New Case

I ordered the Argon One M.2 case after a short search. I was looking for a solution that allowed me to mount and connect an M.2 SSD. In this sense, there were far too many options. There are a number of “bare board” solutions, including one from Geekworm and another from The price points were similar, hovering around $25 per board. However, the bare board required me to buy a new case, and most of the “tall” cases required for both the Pi and the bare board ran another $15-$25, so I was looking at around $35-$45 for a new board and case.

My Amazon searches kept bringing up the Argon One case, so I looked into it. It provided both the case and the SSD support, and added some thermal management and a sleek pinout extension. And, at about $47, the price point was similar to what I was going to spend on a board and new case, so I grabbed that case. Hands on, I was not disappointed: the case is solid and had a good guide for installation packaged with it.

Always read ahead…

When it comes to instructions, I tend to read ahead. Before I put everything in the case, I wanted to make sure I was going to be ready before I buttoned it up. As I read through the guide for getting the Argon One case running with a boot to SSD, I noticed steps 16 and 17.

The guide walked through the process of using the SD Card Copier to move the image from the SD card to the SSD card. However, I am planning on using the Home Assistant OS image, which means I’ll need to image the SSD from my machine with that image. Which means I have to get the SSD connected to my machine…

Yet another Franken-cable

I do not have a USB adapter for SSD cards, because I do not flash them often enough to care. So how do I use the Raspberry Pi Imager to flash Home Assistant OS onto my SSD? With a Franken-cable!

I installed the M.2 SSD in the Argon One’s base, but did not put the PI on it. Using the bare base, I installed the “male to male” USB U adapter in the M.2 base, and used a USB extension cable to attach the other end of the U Adapter to my PC. It showed up as an Argon SSD, and I was able to flash the SSD with the Home Assistant OS.

Updated Install Steps

So, putting all this together, I did the following to get Home Assistant running on Raspberry Pi / Argon One SSD:

  1. Install the Raspberry Pi in the Argon One case, but do not attach the base with the SSD.
  2. From this guide, follow steps 1-15 as written. Then shutdown the system and take out the SSD.
  3. Install the SSD in Argon One base, and attach it to your PC using the USB Male to Male U adapter (included with the Argon) and a USB extension cable.
  4. Write the Home Assistant OS for RPI4 to the SSD using the Raspberry Pi Imager utility.
  5. Put the Argon One case together, and use the U adapter to connect the SSD to the RPI.
  6. Power on the RPI

At this point, Home Assistant should boot for the first time and begin its setup process.

Argon Add-ons

Now, the Argon case has a built-in fan and fan controller. When using Raspbian, you can install the controller software. Home Assistant OS is different, but thankfully, Adam Outler wrote add-ons to allow Home Assistant to control the Argon fan.

I followed the instructions, but then realized that I needed to enable I2C in order to get it to work. Adam to the rescue: Adam wrote a HassOS configurator add on for both I2C and Serial support. I installed the I2C configurator and ran it according to its instructions.

Running on Empty

My new Home Assistant instance is running. It is not doing anything, but it is running. Next steps will be to start migrating my various integrations from one instance to another.