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Ask Slashdot: How Would You Suggest Making Rugged, Weather-Resistant ARM Systems?
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."
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 military and embedded products for this reason.
What a silly suggestion. The raspberry pi 3 is thermally challenged at room temperature. Adding 40C to that would put it well above Tjmax
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.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Think outside the box. Mount your camera at the top of a simple pole mount, then run the wires down to a box at the bottom where the cpu and guts are. Then dig a hole in the ground a few feet deep and bury the box. A few feet down it should stay cool/warm year round with no active cooling/heating.
That is what we use to do with water pipes to keep them from freezing over in winter in the colder climates.
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.