Four Raspberry Pi 5s live in a custom rack I 3D-printed for them, stacked above a 5-port switch. The red frames are Proto-pasta's Amie's “Blood of My Enemies” HTPLA, a translucent red with a name better suited to a metal album than a home network. The black parts are their carbon fiber HTPLA, which is stiffer than regular PLA. HTPLA can be heat-treated to hold its shape at temperatures that would soften ordinary PLA. That's a good trait in a box of computers that never turns off.
The rack runs Home Assistant, backs it up every day, watches every service, opens the house to me from anywhere over Tailscale, and turns home sensor data into live dashboards and a nightly AI-written digest. It also runs Immich, which finds the faces in our scanned family photos so the photo frame can show who’s in each one. NetAlertX keeps a census of every device on the network, and the coffee maker starts my morning brief.
citygroundPi 5, 8 GB, NVMe on Geekworm HATmercedesbenzPi 5, 1 GB, NVMe on Geekworm HATheinzfieldPi 5, 8 GB, NVMe on Geekworm HATtheforumPi 5, 4 GB, NVMe on Geekworm HATEvery Pi takes its name from the home ground of one of my teams.
citygroundSlot 1Nottingham Forest (EPL)
Forest have played here since 1898, on the south bank of the River Trent, about 300 yards from Notts County's ground across the water. The stand built in 1980 on the back of two European Cups now carries Brian Clough's name, and its seats were the first in football to spell out a club name: FOREST. The oldest ground in the rack runs the house.
About the City GroundmercedesbenzSlot 2Atlanta United (MLS)
Open since 2017, with a roof of eight translucent panels that slide open like a pinwheel and a halo video board wrapped around the rim. Atlanta United won MLS Cup 2018 here, beating Portland 2 to 0. It also hosted Super Bowl LIII and a 2026 World Cup semifinal. The roof opens so the world can get in. Slot 2 runs Tailscale, which is how I get into the house from anywhere.
About Mercedes-BenzheinzfieldSlot 3Pittsburgh Steelers (NFL)
Home of the Steelers and Pitt since 2001, on the North Shore along the Ohio River, with giant ketchup bottles that tip over the scoreboard after a score. The sign has said Acrisure Stadium since 2022. I stand with the traditionalists. The Pi that keeps the backups gets the name that never changed. Now it also keeps the names of everyone in our old photos.
About Heinz FieldtheforumSlot 4Memphis Grizzlies (NBA)
Home of the Grizzlies and the Memphis Tigers since 2004, at 191 Beale Street in downtown Memphis. It was the first arena with see-through shot clocks, which the NBA later adopted everywhere, and its floor sits below ground level under a round dome. Slot 4 keeps score for the whole house now. The database, the dashboards, and the nightly digest all live here. The building that made the clock see-through seemed like the right place for it.
About FedExForumSlot 4 reads Home Assistant directly every 15 minutes and pulls the GA4 export from BigQuery each morning. Only computed summaries leave the Pi for Claude.
Temperature, humidity, air quality, thermostats, lighting, motion, occupancy and weather. Each event carries the entity ID, state and reading.
New readings stream in every day, to BigQuery and to the local database on theforum. The cloud project is locked against deletion, and a copy of the full history lives on the Pi.
Nothing here needs a person to start it. Uptime Kuma on slot 3 watches every scheduled job and alerts when one fails or goes quiet.
| Cadence | Job | Where | Result |
|---|---|---|---|
| Continuous | Sensor events sent to GA4 by Home Assistant | cityground | A cloud copy of every reading in BigQuery |
| Every 5 min | NetAlertX scan of the home network | heinzfield | A current list of every device in the house |
| Every 10 min | Photo frame asks Immich who’s in each scan | thepyramid to heinzfield | Names under the photos on the frame |
| Every 15 min | Pull of Home Assistant states, statistics and names | theforum | Dashboards under an hour old |
| Every 15 min | Pull of the NetAlertX device list | heinzfield to theforum | A Network dashboard showing what’s online and when |
| Hourly | Backup freshness check | heinzfield | An alert if the newest backup is over 26 hours old |
| Daily | Home Assistant automatic backup, 7 kept | cityground to heinzfield | A restorable .tar on the Samba share |
| 5:30 AM | NetAlertX device list export, 14 kept | heinzfield | Every device name survives a rebuild |
| First cup, 5 to 7 AM | Coffee maker draws over 500 W, so Home Assistant asks for the morning brief | cityground to libertybowl | The brief plays in the kitchen within about 5 seconds, once a day |
| 7:15 AM | GA4 pull from BigQuery | theforum | Home sensor history in the local database |
| 12:40 AM | Insights digest: summaries computed on the Pi, written up by Claude | theforum | An email to Gmail with trends, anomalies and comparisons |
| 3:30 AM | Database and Grafana settings backup | theforum to heinzfield | The data server can be rebuilt from slot 3 |
NetAlertX runs on heinzfield and scans the home network every 5 minutes. The first scan found 84 devices, which says something about how many things in a house now want Wi-Fi. It only listens and counts. It never touches DNS or DHCP, so if it falls over, the internet doesn’t notice. I named every device by room and type, theforum copies the list every 15 minutes, and a Network dashboard in Grafana shows what’s online and when.
The coffee maker sits on a smart plug that measures power. Idle, it draws under 1 watt. Brewing, about 1,300. When Home Assistant sees it cross 500 watts between 5:00 and 7:00 AM, it asks libertybowl, the Pi on the kitchen counter, to read my morning brief aloud. That happens once a day, so a second cup stays quiet. The plug never switches anything. Home Assistant only watches it. Every cup also logs one event to GA4, so the house now keeps data on my caffeine habit.
Each job lives apart from what it protects, so one failure never takes out the house.
Kuma alerts. Restore the newest backup from slot 3 onto a fresh install.
Home Assistant and the GA4 copy keep running. Dashboards and the digest pause until it's back, then the 15-minute pull and the daily GA4 pull catch up.
Kuma can't report its own outage. Home Assistant shows failed backups under Settings, System, Backups, which is the place to check now and then. The photo frame keeps showing the last names it got from Immich. The device census pauses until it’s back.
Without slot 2 there is no Tailscale, so nothing opens from outside the house. Everything at home keeps running, and Raspberry Pi Connect still reaches every Pi from a browser.
| Service | Address | From outside the house |
|---|---|---|
| Home Assistant | homeassistant.local:8123 | Over Tailscale |
| Grafana dashboards | theforum.local:3000 | Over Tailscale |
| Uptime Kuma | heinzfield.local:3001 | Over Tailscale |
| Immich photo library | heinzfield.local:2283 | Over Tailscale |
| NetAlertX device census | heinzfield.local:20211 | Over Tailscale |
| Shell on any Pi | Raspberry Pi Connect | Yes, from a browser |
| Board | Supply | Boot drive | Note |
|---|---|---|---|
| Pi 5 (slots 1 to 4) | 27 W, 5 V / 5 A | NVMe on Geekworm HAT | A 3 A supply caps USB and peripherals at 600 mA. |
| RAM | 8 / 1 / 8 / 4 GB | Slots 1 to 4 in order. Slot 2 only routes Tailscale, so the data server and its database live on theforum's 4 GB. |