The three software stacks that actually work on a Pi
| Stack | What it is | Protocols | Honest catch |
|---|---|---|---|
| FUXA | Open-source web SCADA/HMI (Node.js) with a drag-and-drop editor — the closest thing to a real HMI package | Modbus RTU/TCP, Siemens S7, OPC UA, EtherNet/IP, MELSEC, MQTT | You are your own integrator and support line; check driver maturity for your PLC generation before promising anyone anything |
| Node-RED + Dashboard | Flow-based tool with a huge community; dashboards and glue logic in an afternoon | Everything, via community nodes of varying quality | Great at dashboards, weaker as a hardened operator panel; flows grow into unmaintained spaghetti without discipline |
| CODESYS + WebVisu | If the Pi itself is the soft-PLC, the visualization is one click away | Its own runtime's world | Only makes sense on the soft-PLC route; licensed runtime with limits in the free tier |
Myth-bust while we're here: AdvancedHMI is Windows-only — it does not run on a Raspberry Pi, despite what half the forum threads imply.
The real parts list
- Raspberry Pi 4/5, or a used thin client if you don't need GPIO — plus the official 7″ touchscreen or an HDMI panel (10″ class);
- DIN-rail 24 V→5 V supply rated for the Pi's real draw — brownouts corrupt SD cards;
- an enclosure or VESA mount that survives the plant floor;
- boot from SSD or industrial SD — consumer cards die of write wear in logging duty;
- total: roughly $150–$300 in parts. The panel-shaped hole in the budget was never the hardware.
The integration work nobody budgets
This is the honest core of build-vs-buy. Before the screen is trustworthy, someone does: kiosk-mode autostart (browser full-screen, no cursor, no screen blanking), a watchdog that restarts the stack when it hangs, driver quirks per PLC generation (S7 needs PUT/GET enabled and non-optimized DBs for classic access; Logix tag types have edge cases), network hardening so the Pi isn't a bridge into the machine network, an update path that can't brick the screen mid-shift, and a backup image so the next failure is a 10-minute reflash instead of a rebuild. A weekend if everything goes right. A part-time project when it doesn't. If that list sounds fun — genuinely, build it; it works. If it sounds like a second job, that's the honest argument for buying.
Try the idea before you build anything
The fastest way to know whether a DIY screen would even satisfy your operators: put the free LineKeeper app on a phone or iPad on the machine network. It speaks EtherNet/IP, Siemens S7 and Modbus TCP, reads Logix tag lists automatically, and gives you the dashboard-and-operator-panel experience in 15 minutes — the same experience you'd spend the weekend building. If it covers the need, you've saved the weekend; if you outgrow it, you've prototyped the requirements for free. And the LineKeeper device in development is exactly this recipe — industrial touchscreen, embedded Linux, built around the Raspberry Pi platform — with the integration hardening already done.
The 15-minute temporary panel
Zero-config tag browser for Logix, drag-and-drop dashboard, operator panel, alarms — no changes to the PLC program.
On a desktop? Scan with your iPhone or iPad to get the free app.For the machine itself: the LineKeeper device — in development — is a self-contained 7″ or 10″ touchscreen built to live on the machine permanently — the same drag-and-drop screens, plus what a phone shouldn't carry:
- Live view of every tag, refreshed twice a second — plus write access with a full audit log
- Operator panel: start/stop, indicators, setpoints — hold-to-run buttons release safely
- Stays useful after the repair: data logging, dashboards, machine diagnostics
Small hardware that helps while the panel is out
- GL.iNet Opal travel router — Wi-Fi into the machine network from a spare switch port, so the phone app can stand in as the screen today.
- Anker USB-C to gigabit Ethernet adapter — wired straight into a spare switch port, the phone sees the controller in seconds; USB-C iPhones and iPads need no drivers.
- VIVO pole-mount VESA arm — puts the temporary screen at eye level on a machine post instead of a chair.
- TICONN IP67 enclosure with clear cover — houses the gateway or Wi-Fi bridge on the machine without bare boards on the rail.
Amazon affiliate links — they never change the price you pay.