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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."
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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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!
(this is offended to the end of comments you post, 120 chars)
... against the people for which the state even gets to exist at all!
"I was just doing my job." never worked in any trial. If you are mentally healthy, you are aware of what you are doing. And you can say no. So if you did't, but said yes, *you* chose to support evil. Not just your superior.