davidp11
@david-patel · Membre depuis mars 2025
Facility manager · hospitality · new to IoT
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Traduit de English par IA ·
J’envoie ceci à notre installateur de stores, la même idée devrait fonctionner.
Sending this to our blinds contractor, same idea should work.
Traduit de English par IA ·
Suite à cela, nous rencontrons le même problème avec les stores motorisés.
Following this, we have the same with motorised blinds.
Traduit de English par IA ·
Je ne savais pas que les versions de Pi OS avaient changé à ce sujet, bon à savoir.
Didn’t know the Pi OS versions changed this, good to know.
Traduit de English par IA ·
Pas besoin de redirection, les appareils initient toujours les connexions sortantes. Je suis aussi du côté exploitation technique des bâtiments, pas informatique, mais j’ai vécu cela à notre hôtel l’an dernier lorsque notre prestataire informatique a placé tous les capteurs des chambres et la passerelle de la chaudière sur un SSID séparé, et j’en ai beaucoup appris.Ce dont les capteurs ont besoin en sortie :
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 certificateRien en entrée. Sur le réseau invité de l’AX55, avec « voir les autres appareils et accéder à mon réseau local » désactivé, vous obtenez à peu près ce qu’il faut : les ESP peuvent accéder à Internet mais pas à l’ordinateur portable.Mon hypothèse pour votre capteur de test : soit il ne peut pas résoudre le nom d’hôte (certains réseaux invités distribuent des DNS étranges), soit il n’arrive pas à obtenir l’heure. Chez nous, c’est exactement ce qui s’est passé : les ESP échouaient sur TLS parce que NTP était bloqué sur le nouveau SSID. Surveillez la sortie série si vous le pouvez.Côté Hermetry, ouvrez votre profil d’appareil et vérifiez la liste de durcissement sur la page de sécurité du transport des appareils : MQTT non chiffré désactivé (TLS uniquement, port 8883), jeton dans l’URL désactivé, commandes autorisées sans TLS vide. Il existe aussi un champ Réseaux autorisés (jusqu’à 64 réseaux ou adresses) ; les appareils situés en dehors sont refusés. Si votre domicile dispose d’une IP publique fixe, vous pouvez l’indiquer ici, ainsi un jeton copié depuis une carte sera inutilisable ailleurs.Pour votre page compteur : avec l’isolation activée, votre téléphone sur le Wi-Fi principal ne pourra pas l’atteindre. Nous gardions un ordinateur portable sur le SSID des appareils pour ce genre de cas.
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.
Traduit de English par IA ·
Suite à cela, nous avons les mêmes capteurs restants dans deux de nos hôtels.
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.
Traduit de English par IA ·
Le Pi n’a-t-il pas déjà son propre capteur de température ? C’est ce que lit vcgencmd, je pense.
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.
Traduit de English par IA ·
nous utilisons la même configuration Feather à l’hôtel, une passerelle d’intérieur Basics Station à 8 canaux coûtait à peu près le prix de deux Feathers
we use the same Feather setup at the hotel, an 8-channel Basics Station indoor unit was about the price of two Feathers