davidp11
@david-patel · Mitglied seit März 2025
Facility manager · hospitality · new to IoT
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Von English mit KI übersetzt ·
Ich schicke das an unseren Jalousien-Dienstleister, die gleiche Idee sollte funktionieren.
Sending this to our blinds contractor, same idea should work.
Von English mit KI übersetzt ·
Im Anschluss dazu haben wir dasselbe Problem bei motorisierten Jalousien.
Following this, we have the same with motorised blinds.
Von English mit KI übersetzt ·
Ich wusste nicht, dass sich das bei den Pi OS-Versionen geändert hat, gut zu wissen.
Didn’t know the Pi OS versions changed this, good to know.
Von English mit KI übersetzt ·
Keine Weiterleitung nötig, die Geräte bauen die Verbindungen immer selbst auf. Ich bin auch eher Facility-Management als IT, aber ich habe das letztes Jahr in unserem Hotel durchgemacht, als unser IT-Dienstleister alle Zimmersensoren und das Heizkessel-Gateway in ein separates SSID gelegt hat, und dabei habe ich viel gelernt.Was die Sensoren ausgehend benötigen:
TCP 8883 MQTT over TLS to the device host on your Connection details card
TCP 443 only if any of them use the HTTPS device API
UDP 53 DNS (they connect by host name, TLS needs the name)
UDP 123 NTP, the ESP needs real time to check the server certificateEingehend nichts. Im AX55-Gastnetz mit ausgeschaltetem „Sehen sich gegenseitig und Zugriff auf mein lokales Netzwerk“ erhältst du in etwa das Richtige: Die ESPs können das Internet erreichen, aber nicht den Laptop.Meine Vermutung für deinen Testsensor: Entweder kann er den Host nicht auflösen (manche Gastnetze verteilen seltsame DNS-Server), oder er bekommt keine Zeit. Bei uns war genau das der Fall: Die ESPs scheiterten beim TLS, weil NTP im neuen SSID blockiert war. Schau dir nach Möglichkeit die serielle Ausgabe an.Auf der Hermetry-Seite öffne dein Geräteprofil und prüfe die Härtungsliste auf der Seite zur Geräte-Transportsicherheit: Klartext-MQTT aus (nur TLS, Port 8883), Token in der URL aus, Befehle ohne TLS erlaubt leer. Außerdem gibt es ein Feld Erlaubte Netzwerke (bis zu 64 Netzwerke oder Adressen); Geräte außerhalb davon werden abgewiesen. Wenn dein Zuhause eine feste öffentliche IP hat, kannst du sie dort eintragen, sodass ein von einer Platine kopierter Token andernorts nutzlos ist.Für deine Zählerseite: Mit aktivierter Isolation erreicht dein Handy im Haupt-WLAN sie nicht. Wir hatten dafür einen Laptop im Geräte-SSID.
No forwarding needed, the devices always call out. I’m a facilities guy too, not IT, but I went through this at our hotel last year when our IT contractor put all the room sensors and the boiler gateway on a separate SSID, and I learned a lot from that.
What the sensors need outbound:
TCP 8883 MQTT over TLS to the device host on your Connection details card
TCP 443 only if any of them use the HTTPS device API
UDP 53 DNS (they connect by host name, TLS needs the name)
UDP 123 NTP, the ESP needs real time to check the server certificateNothing inbound. On the AX55 guest network with „see each other and access my local network“ switched OFF you get roughly the right thing: the ESPs can reach the internet but not the laptop.
My bet for your test sensor: either it can’t resolve the host (some guest networks hand out odd DNS), or it can’t get time. Ours did exactly that, the ESPs sat there failing TLS because NTP was blocked on the new SSID. Watch the serial output if you can.
On the Hermetry side, open your device profile and check the hardening list on the device transport security page: plain MQTT off (TLS only, port 8883), token in the URL off, commands allowed without TLS empty. There is also an Allowed networks field (up to 64 networks or addresses); devices outside it are refused. If your home has a fixed public IP you can put it there, so a token copied off a board is useless anywhere else.
For your meter page: with isolation on, your phone on the main Wi-Fi won’t reach it. We kept one laptop on the device SSID for that kind of thing.
My pool sensor did weird stuff when there was condensation on the face, worth wiping it.
I’m a facility manager, not an engineer, but we had exactly this with meters in our hotel’s annex, and our electrician explained it to me. Two buildings with separate supplies don’t sit at the same ground potential. Your RS485 signal is measured against the gateway’s ground, and the MAX485 only tolerates the bus being about -7 to +12 V away from its own ground. When something big switches in building B, the difference jumps past that and the chip dies. Shield grounded at both ends also lets current flow along the shield between the two grounds, which makes it worse. He measured several volts AC between the two grounds with a meter.
What fixed ours, per the electrician:
- An isolated RS485 transceiver on the gateway (ADM2587E or ISO3082 type, or a ready isolated module). The bus side floats with the bus, the Pi side stays on the Pi’s ground.
- Shield grounded at one end only, and a third wire as signal reference between the transceivers.
- Surge protection (TVS diodes made for RS485, like the SM712) at the building entry, which also covers Michael’s lightning point.
Since the change, two years without a dead chip.
And for „nobody notices“: our gateway script sends v1/gw/disconnect for a meter that stops answering three polls in a row, so the child goes offline in Hermetry, and the profile of the meters has an offline alarm. We get a message within 15 minutes.
Von English mit KI übersetzt ·
Anknüpfend daran haben wir in zwei unserer Hotels dieselben übrig gebliebenen Sensoren.
Following this, we have the same leftover sensors in two of our hotels.
Didn’t know about 34 to 39 being input only, noted.
Way over my head, but following because we’re getting LoRa sensors next year.
I’m not an engineer, but I fought this exact error for a week with a Pi 3 and a heat meter in our hotel’s boiler room, and it was two things together.
On a Pi 3 the proper UART (PL011) is wired to Bluetooth and the GPIO pins get the mini UART, ttyS0. The mini UART’s baud rate follows the core clock, so when the CPU changes speed the 9600 isn’t 9600 any more. The mini UART also has no parity, and your meter is on 8E1. So the meter hears your request, answers, and the Pi can’t make sense of the reply.
Second one got me: the serial login console. If cmdline.txt still has console=serial0,115200, the Pi writes its login prompt onto the RS-485 bus at boot and keeps a getty on the port.
What fixed it for me:
# /boot/firmware/config.txt (or /boot/config.txt on older images)
enable_uart=1
dtoverlay=disable-bt
sudo systemctl disable hciuart
# raspi-config: Interface Options > Serial Port
# login shell over serial: No, serial port hardware: YesReboot, then use /dev/serial0 (it points to ttyAMA0 after this) in pymodbus. Also check whether your meter counts registers from 0 or 1. Schneider manuals list them 1-based, so 3028 in the book is 3027 on the wire, and you had that right.
Not an engineer, but our hotel hosted a rescue robotics demo last spring and I spent the day asking their team exactly this. What they did, and why:
Video and driving went over a tether: a thin cable on a reel on the robot paying out as it drives. They said every radio they tried for video failed in their rubble tests, and a cable also means the robot never loses control when it turns a corner.
Telemetry and an emergency stop went over a separate sub-GHz radio (868 MHz in Europe) at a low data rate, so if the tether snapped the operator could still stop it and still see gas readings.
When they had to go wireless for video they dropped small relay nodes behind the robot as it went in, each one in sight of the last.
4G was useless underground for them. The base station laptop was the only thing that talked to the internet.
For your dashboard: the laptop forwards the telemetry over MQTT, the robot never talks to the cloud itself. If you do use LoRaWAN rather than point-to-point LoRa, Hermetry’s network server follows the gateway’s frequency plan, so EU868 gear in Ireland.
Von English mit KI übersetzt ·
Hat der Pi nicht schon einen eigenen Temperatursensor? Den liest vcgencmd doch aus, glaube ich.
Doesn’t the Pi have its own temperature sensor already? That’s what vcgencmd reads I thought.
Is cron running it at all? Ours never ran because the script wasn’t executable
Way over my head, but is the board in a metal box? Ours lost GPS completely in a steel enclosure.
Von English mit KI übersetzt ·
Wir verwenden im Hotel dasselbe Feather-Setup; ein 8-Kanal-Basics-Station-Indoor-Gerät kostete etwa so viel wie zwei Feathers
we use the same Feather setup at the hotel, an 8-channel Basics Station indoor unit was about the price of two Feathers