I have gone through several posts in this discussion about the “Best hardware platform” for OpenHab. I think there is no “Best hardware” available, but something that is “best suited” for the particular application and environment. I am currently thinking of a Rpi3B but it really doesn’t fit well to my environment requirements. Here is what I am looking for in the computing platform:
Powered by DC (8V-16V)
Low Power (24/7 operation with “bridge power” from a battery for a minimum of 24h) in case for main power outage
Ambient Temperature range -20C to +40C
Head Less operation
Passive cooling
Industrial application
CAN (Controller Area Network) hardware interface support
Ethernet Connection (wireless not required)
Support of OpenHab (main usage is to use CAN interface to gate data between other devices and use in combination with InfluxDB to record data; use HabPanel for system GUI); therefore I think Linux OS will fit best
Reliable (i.e. USB connected SSD storage for data and OS?)
The rPi3 would be a candidate, but the ambient temperature requirement might be questionable to fit the rPi3.
Any suggestions are greatly appreciated!
why is ambient temperature an issue?
Iam running bananapi outside in my garden for four years now, with temperatures -23C +35C (recorded maxes) without any issues at all
one rpi I do have in the attic, where temperatures these days are around 50C
I may be a bit in the minority here, but I am firmly and strongly of the opinion that openHAB is not suitable as an industrial control system. You want a real time system with built in fail safes and a far greater degree of consistency of operation and reliability than the openHAB’s parallel architecture can ever hope to support.
So from that alone I recommend against using OH in the first place. You need to be looking elsewhere, especially if you are looking to control or monitor systems that could cost money, damage, injury or death.
The Raspberry Pi is built from commercial chips which are qualified to different temperature ranges; the LAN9514 (LAN9512 on older models with 2 USB ports) is specified by the manufacturers as being qualified from 0°C to 70°C, while the SoC is qualified from -40°C to 85°C. You may well find that the board will work outside those temperatures, but we’re not qualifying the board itself to these extremes.
-20°C is pretty far beyond the LAN9514 chip’s operating range.
It may work but RPi won’t certify it. And for an industrial application, may is not good enough. They need to know that it will work in those ranges.
I’m with @rlkoshak. Having spent some time working with large scale industrial automation (e.g. CACH - Wikipedia), the nondeterministic nature of openHAB will give you nightmares. If timing and order are important to you (e.g. if you’re planning to fire PLCs through that CAN), you should stock up on pain meds to help deal with the headaches that will accompany the use of openHAB.
I think I was not clear enough in my requirements, I agree with @rlkoshak and @mhilbush, the rPi and openHAB is by no means intended to do the control function of the system. rPi and openHAB is intended to “listen” to the CAN bus info and be used as a data recording device and GUI gateway. The control will be performed by a realtime controller with guaranteed latencies and appropriate diagnostics and fail safe operation. You might say that even for recording the realtime sequential recording of info is also not guaranteed, agreed, but this is not mission critical in this instance. The application is a first proof of concept and is therefore not intended to ever go beyond a demonstration. The emphasis is more on the simplicity of development and ease of modification/adaptation of the GUI and the ability to use different devices (smart phone, Web Browser, Tablet). In that sense HabPanel and the Basic GUI for iPhone and Android phones are perfect candidates in combination with Grafana to easily visualize the data and interact with the system…
I agree, with that clarification, OH does seem like a reasonable choice. With that said, I’m afraid I don’t have any recommendations for an SBC that would be suitable. As you see with the RPi, that min temperature is going to eliminate a lot of your options. I did find this thread which might give you a rabbit hole to go down.
We are in the quotation phase, so I hope to get the contract. I am pretty sure it will get some press once it is demonstrated. It would be good for the openHAB community to see…
It runs on “Linux Mint”, so my hope is that openHAB will run using standard Linux installation procedure…
As a plus, this one has an add-on plug in card with CAN
Not sure where you are located… These guys make some reasonably priced industrial and ruggedized platforms, some of which have wide temp ranges and CAN bus support. But, unfortunately, I think they currently distribute just to the US.
@mhilbush, great find! I am in the US and it looks like one of their west coast locations is just around the corner
They key will be how complex it’ll be to pipe the CAN data in and out of openHAB…
Thanks @MDAR for the suggestion, I looked at it, but it does not specify if it can run down to -20C. This is a major requirement. I could test it, but I’d rather get hardware that has been designed with that in mind and that has “proof” for doing so…
MDAR
(Stuart Hanlon, UK importer of Velbus hardware)
17
That’s a big ask for any manufacturer.
I think you’ll need to make your own enclosure and keep the inside to a ‘reasonable’ temperature.
Yes, it is! That’s why I suggested Logic Supply. Although I have to admit I’m a bit surprised by the $646 US price-point on this item with operating temp specs of -25°C - 70°C.
@mhilbush, price is somewhat high, but you get a lot for the money, that will save work downstream: DIN rail mountable, CAN built in, RS232/433/485, power ON option selectable, auto shutdown based on power source voltage (prevent battery drain)!, TVS input protection, shock resistance to 50g…!
That will satisfy all my dreams, the only thing I have not found yet is the power consumption…
I would say -20C is not a huge problem for devices like this. The problem is it will create condens. So you´ll need to get rid of that. An idea could be to build a isolated box to put it inside. Then you´ll probably never reach -20C after all. If it gets too hot, you´ll need to add some ventilation, which may/may not mean, you also need to add a flap to open the box. Perhaps just playing around with ventilation holes could be an easy solution. But when it´s hot, you´ll need ventilation for sure.
