Ask Slashdot: How Would You Suggest Making Rugged, Weather-Resistant ARM Systems? 194
New submitter pecosdave writes: I need suggestions for commercially-made ARM systems that will work in temperature ranges from -35F to 140F (-37C to 60C) for an engineering project. These things are going to be in metal boxes on the side of Texas Highways. The existing Intel systems we're using in other areas are all fan-less, but I'm not going to rule out systems with fans. Considering the extremes of Texas temperatures I'm actually contemplating putting fans on top of our fan-less systems anyways. Almost everything I can find pre-made with ARM is a bare board, or something not nearly as temperature tolerant as some Intel systems I can find. The very nature of an ARM processor should be more tolerant simply because they produce less heat, but I can't seem to find any manufacturers exploiting that fact. Slashdot reader pecosdave added more details in a comment: "It's more closely related to speed cameras, but it's not a speed camera. It's for a toll road, and its main job is to take pictures of a sign at about 10 FPS, though less is probably fine, with a time-stamp so if someone runs the toll we have a separate picture of the current price. If there's a problem with the sign it shows up as well. They just want something local to store it I guess in case the fiber link goes down. We're going to run it rather low-res too to keep the CPU and storage overhead low. I figure 640x480@10FPS is reasonable, but that's not set in stone."
Talk to an engineer (Score:5, Insightful)
There are plenty of industrial manufacturers that will get you a custom chip in an IP65 enclosure. My company does these things all the time, but it's a bit more complicated than just putting something in a box. You have to spec the comms, peripherals, serviceability, lifetime, support, software, updates, ...
Fans on top of fan-less design is a bit weird partially because you're going to sacrifice your IP rating and your fan shorting out or seizing up could bring the power and thus the system down. Also a fan is for moving hot air out and cooler air in. An ARM chip in most data collection circumstances won't get as hot as an asphalt highway in summer so you're just exchanging hot air for hot(ter) air, what's the point of a fan?
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Yup.
I work in an industry that buys a fair bit of this stuff, and there are a whole pile of companies that will build you a solution for any combination of hot, cold, wet, corrosive, vibratey, electrically noisy, portable, etc. Most of the companies we deal with mostly do industrial (machine shops, power plants, mining, etc). Like you said, it's a whole package. You need an engineer to really figure out exactly what you need, then you work with them to figure out maintenance and sparing.
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We stick stuff into a metal box, no fans, enamel coating. But the parts are all rated to +85c at 85% humidity (and also -40c?). Ie, they are industrial rated and not commercial rated; which has a drawback that there aren't as many suppliers and you won't find pre-made boards on the web for this.
As an FYI, if you have anything mounted high on poles then don't have any blinking LEDs on the outside. This tends to attract bullets from those looking for some target practice.
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Yeah, fans don't really work if you're trying to do an IP65 enclosure, as those should be fully sealed.
Honestly, something like this could probably be done with a Raspberry Pi nowadays in terms of CPU power, except that the boards don't really meet the temperature range requirements. I'd imagine that you could find something in your Arrow Electronics catalog that would do the trick, though.
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As for enclosures, I'm not sure which cabinet this project is going to be in, I was asked for help, this isn't really the area I work the most but I tend to be good at finding the right things.
It's going to be in a cabinet akin to this, plus or minus on size, probably minus considering what's going into this particular box. Some of the stuff I've built is in cabinets bigger than this by far, and some of it's in smaller, and yes, I've put stuff in nearly identical cabinets.
https://fdotwp1.dot.state.fl.u... [state.fl.us]
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Do we get consultancy fees if we answer this?
The very nature of an ARM processor should be more tolerant simply because they produce less heat, but I can't seem to find any manufacturers exploiting that fact.
The processor heat will be a tiny part of the overall equation.
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>An ARM chip in most data collection circumstances won't get as hot as an asphalt highway.
Doesn't matter - it might not get as hot as the highway itself, but it will get exactly as hot as the ambient air if powered off, and then immediately start heating up further when powered on. Basic thermodynamics demands that ambient air will *always* be cooler than an operating processor, unless you're refrigerating the chip directly.
Now, if you stick the whole thing in a well-insulated sealed box like a styrofoam
paint it white (Score:3, Insightful)
A lot of ARM systems (even raspberry PI) will live life fine at 60C. You will need a nice passive heatsink inside your box (if it is large) or thermally couple the device to the box wall and put a passive heatsink on the outside. You'll need an active heater of some kind in order to operate reliably below 0C, but that is easy. Paint your box white too... that will help keep it cool in the sun. Good luck! Also post to an appropriate reddit rather than slashdot!
Re:paint it white (Score:4, Informative)
Posted something similar in the firehose. A bit of heating would also help with the camera and is probably the easiest option.
60C isn't a problem, most ARM hardware is at least "industrial" temperature range which is up to 85C.
Seal it up to keep dust and moisture out.
There is probably an off-the-shelf CCTV option for this. They have CCTV in cold countries.
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most ARM hardware is at least "industrial" temperature
I think you'll find "most" ARM hardware is in cheap toys and gadgets that barely work outside of room temperature. But if your point was that there is oooodles of ARM hardware available that suits industry then you're most definitely correct. But that is the exception not the norm.
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Most of our cameras do have built in heaters. I'm not sure about this one in particular, the final specs aren't picked out, but I doubt they'll be as high-budget as the cameras for reading plates. The plate-reading cameras could just about do the job I'm asking for on their own, they have complete Linux systems in the cameras themselves, the only thing they're missing is sufficient storage.
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That is what we use to do with water pipes to keep them from freezing over in winter in the colder climates.
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There are problems with your suggestion:
1. This is Houston. We are at sea-level. We have electrical ground boxes that we can't pump dry - they're only about four feet deep but they're wells.
2. The box with the CPU and guts is exactly what we're talking about.
3. This is Texas - not as bad here, but note my user-name, I'm from the other side of the state. I've been fifteen feet underground out west in the summer and it's capacitive-hot. Meaning the ground gets baked in the sun all day, so much that the
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(totally off topic reply)
but note my user-name, I'm from the other side of the state
You know, I've seen you post plenty of times before. I think we've even bounced random replies off each other over the last decades. Yet I'm only just now noticing that is an "e" and not "i" in your name.
All this time I thought you were just a really teeny tiny sized Dave :P
Re:paint it white (Score:4, Informative)
But now the box will possibly be wet or moist all year round which has its own problems. By the side of a road means you'll get some odd toxic stuff there too so you need to make sure things are resistant to corrosion. Even if above ground you can often get a lot of salt corrosion if you're closer to the ocean.
Beware of people intent on tampering. And animals. We had one product where we were considering a more expensive armored cable just to avoid problems with rodents.
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Tampering and rodents aren't really a big issue. They're solid aluminum enclosures that are well sealed with sealed conduits, there are vents at the top under an awning/shade with fans and a mesh grill. Birds getting up in there might be an issue, but it's likely to be too hot to build a nest considering location. it's going to be right off a major toll-way and freeway with plenty of patrols and the OTHER cameras for toll collection and overview nearby in the open. I'm not going to say it's not going to
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Are there wires that come out, such as to get power or connect to sensors?
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The wires come up through a concrete slab it is sitting on in some cases, or through armored conduit that has hermetic seals at the bottom of the box.
This is serious road-side work here, there's very little exposed wire anywhere, maybe the last few feet to few inches between a conduit and a piece of equipment, even then sometimes the conduit screws into the equipment.
Our electrical conduit could be used as plumbing in many cases if it had to be.
Common misconception (Score:2)
For best temperature regulation (easiest to alter the interior temperature), paint it black, and shade it from direct sunlight to inhibit external hea
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Said the guy that has obviously never tried walking barefoot across an asphalt road in summer.
Hint: To avoid blisters on the bottom of your feet, walk on the white stripes.
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What, x86 chips don't need a heater because they run hot by themselves?
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We do have heaters in the x86 enclosures, but they really don't see a lot of use, the enclosures are well enough heated by the systems in the winter. A Houston winter rarely gets severe. I've never seen snow last 48 hours around here, and only 24 hours once since I moved here in 1998.
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Also post to an appropriate reddit rather than slashdot!
Why? He is getting great answers here. Further, some of the most qualified people on the planet are here.
Reddit is high-traffic, so it is a great place to ask, but the person asking has been around Slashdot for a VERY long time (as have you!) so why not ask here? Hell, he might end up with someone like the person who invented Apple (Woz!) answering. John Carmack lives in Texas and might answer too (hasn't in years, but still possible). I imagine working on rockets gives some insight into designing computing
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A lot of ARM systems (even raspberry PI) will live life fine at 60C.
NO!. A Raspberry Pi, unless you're talking about one of the industrial hardened ones will definitely not "live life fine" at 60C. In fact at that temperature it will thermally throttle at no load and be utterly useless. It is barely able to run at load on a hot day if you don't have the AC on.
my raspberry pi & 3D printer says (Score:2)
. Because of low heat you can just use ABS to print a nearly air tight box to put it in and 5v power supply and bob's your uncle.
Re:my raspberry pi & 3D printer says (Score:4, Informative)
What a silly suggestion. The raspberry pi 3 is thermally challenged at room temperature. Adding 40C to that would put it well above Tjmax
Thermally challenged (Score:2)
The raspberry pi 3 is thermally challenged at room temperature.
"Having the thermal throttle kicking in and not letting you have 200fps on whatever thing you're trying to emulate in RetroPi"
!=
"I won't be able to take a shot every now and then".
Also, the poster want to just take a shot every now or then of a street sign.
A Raspberry Pi Zero (lower consumption, cheaper) would to the job okay.
It's SoC is qualified for -40 to +85 (source) [raspberrypi.org], though you'll have to check if the other chip used (wireless functionality of Zero W for remoting, the chip used in the ca
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"Having the thermal throttle kicking in and not letting you have 200fps on whatever thing you're trying to emulate in RetroPi"
!=
"I won't be able to take a shot every now and then".
"Being thermally challenged at room temperature" also != "systems that will work in temperature ranges from -35F to 140F (-37C to 60C) for an engineering project"
Leave your toys in the cupboard where they belong. There are countless more suitable options out there in the world than throwing *the cheapest* toy at the problem.
It's SoC is qualified for -40 to +85
What the SoC is qualified for is completely irrelevant as that qualification does not take into account the final integrated solution. Your raspberry pi will not work (not may not work,
More iBuzzwords please! More cluelessness. (Score:1)
The plastic, like all plastics, will turn brittle incredibly quickly under that hot outdoor sun. If it doesn't get soft outright.
It is also horrible at leading away heat, and will not survive a single e.g. baseball bat.
Basically, your kind of people with that kind of mindset are the cancer that entered our industry, and literally why we can't have nice, lasting things anymore.
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That plastic will bleach, crack (become permeable) and melt in direct sunlight. Plastic in UV light degrades.
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Ah, no. The max temp rating of a raspberry pi is 85C; it would never survive at 140C. It would probably burst into flames.
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I had a bare Pi with no additional heat syncs that couldn't play full HD movie with Kodi before overheating in a 78F apartment in the summer (we couldn't cool that apartment well, metal green front door, lots of sun exposure, the AC just couldn't get it cooler than that in the daytime summer).
I literally work on this kind of thing. (Score:2, Informative)
This is my industry. I've worked with super ruggedized military grade ARM boards. I would go fanless, and for your application you shouldn't need much power. Products end up as metal boxes with fans if they even need that.
You've gotta find vendors which make automotive and military/aerospace grade chips, so the usual Samsung and TI OMAP chips won't always work. NXP is bigger into this space with IMX.6 chips and similar. As much as tons of developers dislike Freescale/NXP, they have a huge presence in m
Stupid idea (Score:2)
I just thought about double sealing it in a small container. The first layer filled with a compressed gas and the second filled with oil. Then have radiator tubes going through it and around, put a tiny 5 inch fan on the bottom so the breeze from the cars helps spin the fan, possible mount a heat sink on top...
I'm just imagining this thing built like a car radiator or computer heatsink, with the breeze off the road that should keep the fan going even with no electric, the pressurized gas + oil double seal
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Just put it in a box and fill the whole thing with epoxy. Use a big enough heat sink that the tips of the fins are exposed. Then mount it upside down so that if it gets wet, the water runs down the fins. :-)
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I like that idea,except here in TX the rains only come around fall and spring and some years it can be hit and miss. I wonder if the epoxy will cause gaps to occur over time like who pool tiles start blistering off after a while....sorry I wasn't trying to be shoot down your idea, im sure mine is shit, at least yours was economically more plausible, lol.
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The box protects against the force of the water. The epoxy protects against the moisture. :-)
I'm not saying it will work, but if it does, it's the simplest approach.
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I wonder if a ceramic based enclosure might be better, it would be more eco/cheap
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Stick to software.
Bulletproof? (Score:2)
Judging from the number signs riddled with bullet holes that I have seen in Texas, you may want to make it bulletproof.
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Absolutely, we had a problem with this with a pole mounted device until we turned off the LED, and this wasn't even Texas.
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Well, if you'd stop shining the bleeping thing in their window at night, maybe they'd stop shooting it out.
Strange how that works.
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That's true in rural areas, usually peppered with a shotgun blasts.
Less common in Houston itself, and then it's usually a single pistol round....
Hint (Score:1)
Search for DIY and off the shelf Raspberry Pi trail cameras.
https://petapixel.com/2018/02/06/motion-detecting-wildlife-camera-made-raspberry-pi/ [petapixel.com]
https://peaknature.co.uk/blog/how-to-build-a-raspberry-pi-zero-trail-camera--part-1-what-you-need [peaknature.co.uk]
https://www.raspberrypi.org/blog/solar-powered-nature-camera/ [raspberrypi.org]
https://thepihut.com/products/naturebytes-wildlife-camera-kit?variant=28137973841 [thepihut.com]
You're asking the wrong question (Score:2)
Thermal management for high temperature is easily managed. You're very concerned about the high temperature when that is the easy one to deal with. Any ARM chip thermally bonded to the side of the case / large heatsink which is somehow externally accessible and allows minimal airflow should be able to handle the upper side of your temperature requirement.
Your problem will be at the other end. Sustained electrical performance at -37C is something many components are not rated for. Even in industry there are
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Typical "industrial" temperature ranges: -40C to 100C
"Automotive" range usually bumps the high end up to 125C.
Thermal isn't the OP's biggest problem here, IMHO.
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Errr. Those are thermal characteristics of components, especially in the automotive side of things. Actually integrating that into a complete design that actually works through the range of those temperatures *environmentally* (remember he didn't specify 60C is his max SoC temperature) is incredibly bloody difficult. You got a chip that's qualified for that temperature at ambient. Does that include loading the chip to it's max ratings while at that temperature or is that in typical operation. Your ambient t
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A lot of camera systems simply come in a case with their own heater systems and the 'guts' are simply standard cameras. That's presuming you can power the system reliably.
Heating a thing is easy, cooling is typically a harder engineering problem although I agree for the use case he mentioned, I highly doubt you have that much of a thermal envelope.
A few suggestions (Score:2)
The cold will get you too (Score:2)
Texas Records (Score:2)
The record high in Texas was 120 F in Seymour, TX in 1936 and -23 F in Tulia, TX in 1899. The range is considerably less along MO-PAC.
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As my user name shows, I grew up in Pecos.
Pecos did not have an official weather station that counted until less than a decade ago. While I was in high-school it made it to 128 one summer - of course the closest weather station was in Kermit and that's what shows as the official temperature for Pecos. My dad claims it made it to 132 in the mid 70's while he was still working cattle.
It has not gotten past 116 or so since that summer it hit 128 in 94 or 95.
What's fun is I used to pick cantaloupe with the mi
Power constraints? (Score:2)
With enough power available at each site, anything is possible.
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Well, if we evacuate the atmosphere of the planet and tidally lock it (might need to move a bit closer to the sun) such that Texas is on the cold side, that should mean all you need then is a heater and you can basically keep your box running at/near 0C constantly. Added bonus that without atmosphere there'll be no condensation and much less work for the camera software.
Technologic Systems (Score:1)
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I like that site, I've been all through it, but it's got the initial issue, it's all bare-board stuff.
I may be able to convince them to go with something bare-board, or to custom make my own enclosure, which I can totally do, but for some reason when you go ARM all the nice big heat-sink ready to go systems go away.
The closest thing I can find ARM wise to what I'm looking for are those media PCs for TVs, and they aren't exactly industrial grade. I've used bare board stuff in integrated systems, but this is
Texas? 60C? (Score:2)
How to make ARM work (Score:1)
2. Find the code to make all the parts that make a computer work with ARM.
3. Test the ARM OS and ARM ready computer parts.
4. Find a factory that makes the needed temperature tolerant enclosure.
Heat will need to be moved. A fan might become more of a problem over time/the ability to cool.
Look at people in the USA who make trail cameras/remote camera https://en.wikipedia.org/wiki/... [wikipedia.org] .
Why? They know of all weather US conditions.
Software and hardware
Temperature of Texas highways (Score:2)
Done this several times for one-off systems... (Score:2)
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This is actually one of the best suggestions I've seen, and actually not that far off from the mil-spec vehicle devices I considered. We would rather stick with standard connectors, that's what the Intel servers we have in the air-conditioned boxes. For some reason when you cross the CPU divide you go from normal computer stuff to mil-spec or bare board only.
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Embed in Epoxy (Score:2)
They make whole devices that do this (Score:2)
At least I'm pretty sure they do everything you want. They're called "dash cams". If they can survive the interior of a hot car, they can survive this.
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My dash cam has only semi-survived the heat in my vehicle, it's a good brand, it's a Cobra.
It quits working sometimes if I have to park in the sun in the summer until I get the air conditioning going again, I have to cool it off then power cycle it. Also, it's not wired for IP, the camera is built into the recorder and the battery didn't survive a full year, so when the car gets shut down it doesn't have the two or three minutes of additional recording time.
That being said one of the items I submitted for
Why do you need a separate box? (Score:2)
Many IP cameras already have a micro SD card slot and can record video to the SD card in addition to streaming it offsite. A quick search on Amazon found one that is IP67 rated and has temperature ratings from -40c to +60c for $86, Dahua IPC-HDBW4431R-ZS. Iâ(TM)ve used Dahua cameras before and their optics and image sensors are great but their network security is lousy. Keep them on an isolated VLAN and donâ(TM)t let them connect outbound to the Internet.
VIA AMOS (Score:2)
Many manufacturers make ARM-based industrial-grade systems, e. g. the VIA AMOS 820 or the VIA AMOS 3003.
https://www.viatech.com/en/sys... [viatech.com]
https://www.viatech.com/en/sys... [viatech.com]
Raspi Zero W is fine with heat (Score:2)
I have a Zero W (with a stick-on SoC heatsink) in a box in my back yard that runs fine when the temperature in the box gets in the 50-60C range. Guess I could try it in a freezer to see how it does with cold.
My rates are very reasonable :) (Score:2)
NetBurner (Score:2)
[netburner.com] https://www.netburner.com/prod... [netburner.com]
In the past, we just seal up the housings against the elements, using appropriate vent holes if need be. I agree with other posters, if this field is new to you, you may want to consult local engineers who do this sort of thing as there are gotchas and maybe even laws to consider.
My company makes one of these (Score:2)
Beagle Bone Black Industrial (Score:2)
Check out the BBB Extended Temperature range ->> -40C to +85C
Plus a full Linux system for your development and deployment. I have used several for industrial apps with a custom daughter board with serial port connectivity.
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Link
https://beagleboard.org/e14-bb... [beagleboard.org]
Plenty of options... (Score:2)
We use imx6 industrial parts that are rated -40 to +95 C - that should be enough? Is the problem that you want something off the shelf? (We design our own solutions)
I think I found a winner! (Score:2)
There were lots of good suggestions here, but few were actual pre-built in chassis systems - like the Intel ones I mentioned. This came from an online buddy, I found a few in-vehicle systems that were alright, but this one stands out. Not the exact form-factor I was looking for, but it will do.
https://www.rugged.com/a177-tw... [rugged.com]
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Please take your anti government shit rant back to 4chan where it belongs.
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I'm pro-government, and I probably hate toll roads even more than the other guy! LOL
But the more serious answer to the question is, if it is an "engineering project" then your engineer should be telling us, you shouldn't be asking slashdot.
Are you going to need cooling? Yes, you're going to need cooling. Assuming that you have money, since you don't have an engineer you must still have the money, so you should buy a refrigerated water cooling system, and you're done asking about that part.
Since you're in Te
Automotive or milspec line. Or te Zach to call Ray (Score:3)
Thanks for getting this back on topic.
TI and others make units designed for automotive use which are speced for those kinds of temperatures. They are expected to work under the hood of a car, in Texas.
Just Google automotive micros or socs as needed, or call any manufacturer.
Milspec parts are similar temperatures plus a higher reliability rating.
Or, submitter could ask Zach, who works in signaling, which would then text Ray. :)
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And theft resistant.
Could you have a Beowulf cluster of toll sign monitors?
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On a side note to the original poster, the reason fanless is chosen is that fans have a really short mean time to failure (depending on conditions, fan quality etc.) rel
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For shits and giggles I googled it for you BAE Systems RAD750 3U cPCI Single Board Computer
Dude, that's a bit mean :-).
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if the ambient temperature is higher than the rated temperature of the silicon it doesn't matter how many fans you pack in, it's going to die.
The silicon part of the chip won't have problems below 150C; other parts of the package will fail first unless it is a ceramic package or the temperature increase was caused by over-current.
There are 0 toll roads on the planet Venus. Zero (0). Where else would have outside free air temperatures that high, and also have enough gravity for a toll road to make sense?
That said, if the temperature inside the box without a fan would exceed them temperature limits of the [IC package] that does not imply that you c
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Or... like it says in the summary, they're not taking pictures of cars. They're taking pictures of the toll road sign.
I assume it's for disputes, where the defendant tries to claim the electronic sign wasn't working.
As for the actual question being asked, seems like they're trying to find a solution that fits their preconceived beliefs that ARM based systems must be more power efficient that x86, so therefore must do better in hot environments.
You'll find that ARM systems are gear towards mobile application
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This isn't true. Check out Texas Instruments. For example, all their Sitara processors are available up to 105C.
http://www.ti.com/processors/s... [ti.com]
I didn't even look at other lines, I just clicked the first product lines that would do the stuff in the question, eg push 32 bits around moderately fast.
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Cool! (or Hot!, I suppose)
So is that typical, or is TI an exception?
I know I still love my TI-85 calculator - I must have a first-year 1992 model as I think of the timing. That sucker has taken almost 30 years of abuse and is still going strong. I just have to remember to replace the AAs every couple of years when I cant crank the screen darkness high enough any more.
Anyway - I recall them being quite proud of the durability of the thing in their marketing, and could easily see them being an outlier in th
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That is typical for quality suppliers. If your chips come from a random small fab in Shenzen, probably not.
Across most integrated circuits that are available from multiple vendors, you'll find high quality ones from TI, including automotive and milspec parts.
For ARM in particular, high quality is their thing top to bottom. At the bottom you have MSP432 which is a really cheap microcontroller, but with a better ADC and lower power usage than similar units from other manufacturers; for a few cents more, of co
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You'll find that ARM systems are gear towards mobile applications.
I'm sure these systems will be quite mobile once people find out there are free PCs sitting around on TX roadsides ...
Re: Intel just hides inefficiency outside the chip (Score:2)
Atom has certainly crossed my mind. I was a fan of netbooks at one time as my coffee shop cruisers and I was impressed with them. I have not however used them for long term harsh work. I've had them not do to well under abusive loads, then again they were in netbook format, and old models of chips.
Atom is still on the table, and I won't be making the end decision. I found some nice Atom based systems packaged in passively cooled industrial cases like in looking for.
I am trying to avoid Windows due to the
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Funny rant from that guy, about roads provided _by_ the very government he's pissed at. Unbelievable unaware.
It happens all the time. For instance, some inmates complain about the prisons provided _by_ the very government they're pissed at.
Nobody should be allowed to complain about the government. They should just be grateful for whatever they get.
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You heard it first on Slashdot folks, toll road payment checking system = war crimes.
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One of the potential systems I've submitted was an appliance meant for use in aircraft. I found some automotive ones as well. I have no idea how much any of those costs, every supplier I found wanted full company info for a quote, it makes it difficult to shop around.
Alternately pre-built full systems tend to at least sometimes have a price-tag next to them. Systems like are off the shelf and akin to what I want [logicsupply.com] but out of spec. I'm trying to shop a little before settling on a supplier. Unfortunately I
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You realize this is exactly what I asked for.
ARM = bare board.
Intel = prebuilt system with a huge heat-sink on top, exactly what I'm looking for in ARM
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At the toll-rate you're talking about less than a month to pay for itself. This contract is for somewhere in the neighborhood of 40 years. It's quite likely the equipment will be replaced many times over, paying for itself many times over each time, before the contract is up.
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Ambient temperature in the shade can reach above 100F easy.
A three foot deep hole in some of the areas we've already got three feet deep holes is a water well.
Even though this isn't a TXDOT project TXDOT is still involved and wouldn't approve something like that. They're pretty strict about enclosures.
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I like it, I'm calling the people from the US distributor now to see if we can build something from that closer to what I need.
Still, a board, but I like it.
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You've probably thought of this, but I'll mention it in case you haven't. If your primary concern is high temperatures, make sure the boxes are painted white. If the bigger problem is low temperatures, pain them black.
As for fans, make sure your thermal design doesn't require them under any except the most extreme conditions. The vast percentage of the time fans shouldn't be bringing equipment temperature into the desired operating range, they should be bringing it farther into range.
Re: (Score:2)
The boxes they're in are reflective aluminum and are unlikely to be painted unless some city official or something has a community outreach program and lets an artist pain them at some point. That's always possible and I've seen it with other boxes around the city, but never toll road ones.
Re: (Score:2)
The range requirements are contract requirements.
I honestly doubt we're going to see anything near the bottom requirement anytime soon, the top requirement I think we need to exceed....