PowerDot 146 – 1,46-Zoll-Runddisplay für die Victron-Anlage über MQTT

Saw something similar pop up in a German forum recently — a tiny round display pulling Victron data via MQTT, and honestly it got me thinking about my own setup.

Been running a Victron Cerbo GX for my emergency backup system and the monitoring side is decent but I'm always looking at ways to get a quick glance at SOC and grid status without opening VRM or fumbling with the phone. A small dedicated display mounted somewhere visible would be ideal.

Anyone here experimented with compact round displays pulling data from Victron over MQTT? I know Node-RED is the obvious route for parsing the data, but curious whether anyone's gone down a more plug-and-play path.

Few things I'm wondering:

• MQTT broker — running Mosquitto locally on a Pi, is that what most people are doing?
• Display options — seen a few ESP32-based round displays floating about. Anyone tried something like that with UK voltage/setup considerations?
• Reliability — for emergency backup use this has to be dependable. No point having a status display that drops off when you actually need it

Not after anything fancy, just SOC percentage, charge state, and maybe grid/inverter status at a glance. Something I could mount near the consumer unit.

Would love to know if anyone's built something similar or has recommendations for displays that play nicely with Victron's MQTT topics. Feels like the kind of project that looks simple until you're three hours deep into JSON parsing at midnight.

@TelScott75 interesting concept — I've been doing something similar in my van build using an ESP32 pulling MQTT data from the Cerbo GX. The round display format is genuinely useful for a single KPI like SOC or battery voltage; you're not trying to replicate VRM on a postage stamp.

Worth noting the Cerbo's MQTT broker needs enabling manually under Settings > Services — not on by default and catches people out.

My concern with these boutique displays is longevity. If the firmware stops being maintained you're stuck. I'd rather build on ESPHome or Tasmota with a cheap GC9A01 round display module from AliExpress — total cost under a fiver, fully customisable, and you own the stack completely.

Has anyone confirmed whether the PowerDot exposes the raw MQTT topics or locks you into its own cloud layer? That's the dealbreaker for me.

@TelScott75 @GoldenTrekker — worth noting that the Cerbo's MQTT broker needs enabling manually under Remote Console > Services, which catches people out. Also, the VRM MQTT endpoint (mqtt.victronenergy.com) requires an internet connection, whereas the local broker works entirely off-grid, which matters on a narrowboat mid-canal.

I've been running a small LVGL-based round display on my boat pulling N/+/solarcharger/+/Dc/0/Power and SOC topics locally. Latency is negligible compared to VRM polling.

Main caveat: Victron's MQTT topic structure is well-documented but can shift between Venus OS versions — I got burnt going from 2.9x to 3.x. Always pin your Venus OS if a display integration is working reliably.

Good shout @FenlandSolar — and worth adding that once you've enabled the MQTT broker on the Cerbo, you'll want to keep an eye on the topic structure. Victron uses N/{portal_id}/... for read topics and W/{portal_id}/... for write, which trips a lot of people up initially. For a little display like this PowerDot, you're mostly just subscribing to read topics anyway, so it's fairly straightforward once you've got your portal ID sorted (find it under Settings > VRM Online Portal on the Cerbo).

@GoldenTrekker — curious what refresh rate you're running on your ESP32 setup? I'd imagine for something this small you don't need it hammering the broker every second, every 5–10 seconds seems plenty for a quick glance display.

@Paul1999 raises a fair point about keepalive — and I'll add from bitter experience on the boat: don't discover your MQTT broker has quietly stopped publishing at 11pm on a cold February mooring when your battery bank is doing something suspicious.

The round display is genuinely clever for a narrowboat helm position — glanceable data without squinting