I've been running Home Assistant (HA) at home for a couple of years now but setting it up on a Raspberry Pi3B+ in the van has been humbling. I only wanted to add a small capacity dashboard for the Van HTPC desktop, but using a girthy server to run HA in a VM is way easier than using a itty-biity Pi in a hot van. Here's some bullet point items that I've learned while pounding my head against the wall over the last couple of weeks:
• Raspberry Pi 3B+ is barely adequate for running HA. Don't install add-ons that you think you might use — with just 1GB of memory it's running at the ragged edge of capacity, and you'll know it's struggling when the UI gets sluggish, watchdog reboots start happening, or add-ons get silently killed.
• Get a good USB power supply and a quality USB cable before you do anything else. You'll want a minimum of 3 amps of capacity. The Pi will start on sketchy power but will reboot frequently and probably corrupt the SD card in the process. Don't be tempted to use that 1.2A USB port that's already in the van or the skinny microUSB cable from the junk drawer.
• Don' use that SD card you had laying around, get a High Endurance Video microSDXC card — they handle heat better and are rated for the constant small writes that HAOS generates. SD card corruption is one of the biggest failure modes on a Pi, caused by power loss, dirty shutdowns, and write wear. 32GB is the bare minimum capacity; go with 128GB if you plan on any logging.
• Heat is a big concern in the van, so make sure you have a good Pi thermal case. I switched to a fanless passive case — a fan-cooled case sounds better in theory, but a failed fan in a hot van is worse than no fan at all, as I found out.
• The Pi doesn't switch to an available WiFi network the way the Cerbo GX or your phone does. You only get one SSID so give some thought to which one you connect to. I connect to my home WiFi so I can tweak the Pi in the driveway, and connect via ethernet to my travel router on the road. That will probably change as I get everything dialed in.
• The HA software installs with a Matter server running. It's a resource hog on a Pi 3B+, so uninstall it unless you actually need it.
• Tailscale is available as an add-on but it's also a significant memory drain — on a loaded Pi 3B+, HAOS will eventually kill it when memory gets tight. If you need remote access, consider running Tailscale on your travel router instead and leaving it off the Pi entirely.
• The first apps I install after a fresh HAOS setup (which I've done a bunch of times now) are Backups and Samba. Backups so you can restore your configuration, and Samba so you can pull the entire HA config folder down to your PC — which means if the SD card corrupts, you can reflash and restore from what's on your PC rather than starting from scratch. Then I add Terminal & SSH for command-line access. If you're chasing a lot of reboot problems, it's often faster to start fresh and restore the config folder via Samba than to troubleshoot a destabilized install.
• Update HAOS with caution. A failed update can leave the system unbootable, requiring a full reflash of the SD card — and if your last backup is stale, you're rebuilding from scratch. It took me three or four update attempts before I realized the update itself was failing (out of memory) and corrupting the SD card each time. Always back up the config folder to your PC via Samba before hitting update, and don't update in the field where your recovery options are limited. At home you have your PC, a card reader, and time; on the road you may have none of those.
• The easiest way to connect Victron devices inside the van to HA is using Bluetooth via the Victron BLE integration. That works with or without a Cerbo GX. Once you have that working, you can layer in Victron MQTT, Victron GX, or Victron DRM connections PRN — but BLE was the right place to start for me.
• Be careful with the watchdog function in apps. When enabled, it doesn't just restart the app if it fails — it reboots the entire Pi. On a memory-constrained Pi 3B+, HAOS will kill apps when running low on memory, and if watchdog is enabled on those apps, every low-memory event becomes a full Pi reboot.
Bruce
