Is the memory card actually more expensive than the controller?
Titan submersible’s $62 SanDisk memory card found undamaged at wreckage site
201–210 of 221 posts
Re: Titan submersible’s $62 SanDisk memory card found undamaged at wreckage site
#202I know the default policy is to use the source headline, but I feel the mention of $62 is kindof unfair. It evokes cheapness. Many many aspects of the craft were cheap and underbuilt, but it’s not clear to me that the memory card was one of those areas. Seems like it was an actually useful COTS part
Re: Titan submersible’s $62 SanDisk memory card found undamaged at wreckage site
#203I know the default policy is to use the source headline, but I feel the mention of $62 is kindof unfair. It evokes cheapness. Many many aspects of the craft were cheap and underbuilt, but it’s not clear to me that the memory card was one of those areas. Seems like it was an actually useful COTS part
Yeah, and the title doesn't mention that is for a camera either.
This seems perfectly reasonable for camera data storage, and apparently a camera that's manually operated as well.
It'd be worrying if it was storing the binaries to operate the sub, but this is a decent quality SD card for camera storage.
Re: Titan submersible’s $62 SanDisk memory card found undamaged at wreckage site
#204Earlier quoted context omitted.
So what if you can't replace a screen on an epoxy-filled cell phone? That's a small price to pay for knowing that your camera will survive if you take a one-way trip to crush-depth.
Is this sarcasm? 99.999% people will never take it beyond a meter in a pool.
Poe's Law never fails. I should have accounted for that.
Re: Titan submersible’s $62 SanDisk memory card found undamaged at wreckage site
#205I see a lot of discussion in this thread stemming from some confusion+not reading the actual report[0]. Some key points: 1. The Camera+Card was encased in a separate enclosure made of titanium+sapphire, and did not seem to be exposed to extreme pressures. 2. The encryption was done via a variant of LUKS/dm-crypt, with the key stored on the NVRAM of a chip (Edited; not in TrustZone). 3. The recovery was done by transp…
> 1. The Camera+Card was encased in a separate enclosure made of titanium+sapphire, and did not seem to be exposed to extreme pressures. I wonder what the price of the enclosure was then. Feels a bit like click bait...
It might have been filled with mineral oil, those external enclosures often setup that way so that the enclosure is less extreme to manufacture. Not sure if that would work for camera lenses though unless those were also filled.
Re: Titan submersible’s $62 SanDisk memory card found undamaged at wreckage site
#206Earlier quoted context omitted.
It's a solid piece of silicon encased in epoxy, so there's nothing really to get crushed. Contrast this to something like a cellphone that's made of hundreds of separate parts and has void space that will get crushed.
Why isn't a cellphone filled with epoxy?
Because then it’ll become unrepairable. It’s a tricky trade-off that cell phones/tablets-laptops have to deal with.
Easy to repair vs durable vs cost/time.
And Apple (for example) cares about repairability because they also need/want to repair phones (warranty/trade in for example)
Re: Titan submersible’s $62 SanDisk memory card found undamaged at wreckage site
#207Earlier quoted context omitted.
(I previously wrote something rather crude. I am attempting to revise that into something more positive.) In this context, all people are free to do whatever they want. It is beyond me to suggest that any person cannot do a thing.
Well, but it's not about whether someone can or cannot do something. Since you seem experienced with these devices I'm just asking if there's any technical reason why this might be a bad idea other than the fact that it just doesn't seem like a very professional thing to do. Like for example even though I'm far from an expert I know Raspberry Pis would be awful for any commercial application because they are notoriou…
People do whatever they want. It doesn't have to make sense.
Perhaps disturbingly: I even know of one bit of critical public safety communications infrastructure that is is expensive, low production volume, and has a Raspberry Pi 3 embedded inside. I won't name names because that's getting a little too close to home for my liking, but I was quite surprised to find this inside of a very nice waterproof box with chonky, expensive, olive-colored milspec connectors to connect it up to the outside world.
Which, well: Yeah. There's a ton of good reasons not to do that. But building a whole Linux system on a custom board using individual parts is hard, so it can make sense to buy someone else's work instead.
Except... that's what the CM3 is designed to provide, including on-board eMMC instead of an SD card. I'd not have been surprised at all if there was a CM3 in there, but there is instead an entire Pi 3.
But MCUs, like on the Teensy, aren't like that. They aren't hard to integrate on a custom board like the Broadcom SoC on a Pi 3 or CM3 is.
The primary purpose of an MCU is not to be stuffed onto a dev board like a Teensy, but instead to be stuffed onto the board inside of a microwave oven or an air fryer or a fancy remote control and be easy to interface with other things and to program.
It really doesn't take much to get them going: Some require external ROM or flash, but a lot of them have internal flash memory and only need power and programming pins wired up to let them run code and do whatever IO is needed within a system.
This camera already had at least one very custom board inside. It could have integrated the MCU, as well, instead of the kitchen-sink Teensy.
Doing so is not just style points; it's quite often easier, cheaper, and more flexible.
This allows a person to use all of the IO pins on the MCU to do stuff with, instead of just the functions that the designer of a dev kit decided to build out through whatever interfaces they decided to include.
Re: Titan submersible’s $62 SanDisk memory card found undamaged at wreckage site
#208Earlier quoted context omitted.
The longer I last in this world the more products I realize are the result of telling a few people who don't know what they are doing to "make it kind of work."
That’s my entire experience in embedded. Everything I get from other companies basically looks like an internship project right down to the pointer arguments with unspecified bounds on the function calls. One of the companies we bought hardware from keeps representing things are working when they only work on devices in the lab. Almost nobody in the space produces anything professional and everything uses Yocto even…
> Almost nobody in the space produces anything professional and everything uses Yocto even for two person projects where Multistrap would be more productive.
While I agree with your sentiment that there's a lot of poor software engineering in embedded space (especially in consumer-oriented novelty products, less so in established fields like industrial or telco), I can't but wonder what's wrong with Yocto? In my experience, it's quite the opposite: Yocto is the quickest path to get the firmware for a new device assembled, once you have climbed its pretty steep learning curve. I have built a few homebrew firmware build systems out of Debian and make/shell scripts (not my choice), you pretty quickly find yourself reinventing half of the stuff that Yocto does out of the box, but it's all bespoke, janky and hard to maintain. While with Yocto you just take the vendor's meta layer for BSP, put your application in another, and it bakes you a set of flashable images on the other end, complete with SDKs and other goodies for your dev workflow, reproducibly. It doesn't get significantly more sophisticated once you start to need kernel customizations, firmware updates with A/B partition layout, readonly rootfs, manage board- or customer-specific variants and other features that are very common in embedded systems but poorly or not at all supported in standard distros.
Re: Titan submersible’s $62 SanDisk memory card found undamaged at wreckage site
#209Earlier quoted context omitted.
>They must have crazy margins on that camera and producing custom board is very cheap. It's expensive in time and expertise to do a custom board, and to debug a custom board. All to what, save 20$ on a bom which might not even be 1% of the profit per unit? Far more efficient to just ship the dev board. They could have perhaps picked a better dev setup to start with, but if it looks stupid and it works...
Point isn't to save BOM cost, margins are high already and they can eat into them. Unless they are making literally less than 10 of those, custom board will be easier to manufacture than that mess of dev boards and more reliable than random wires and headers all over the place. Plus they can spend money where it makes sense, using better regulators etc.
Only if you happen to have the relevant skill set.
Speaking as someone capable of designing the mechanical hardware and who is broadly electrically savvy but who is most definitely not an embedded engineer: I could bang out a few hundred hacked together dev boards in week, but doing a custom board would take me a few months. Starting with reading 'Prototyping PCBs for Dummies'.
Re: Titan submersible’s $62 SanDisk memory card found undamaged at wreckage site
#210Earlier quoted context omitted.
Point isn't to save BOM cost, margins are high already and they can eat into them. Unless they are making literally less than 10 of those, custom board will be easier to manufacture than that mess of dev boards and more reliable than random wires and headers all over the place. Plus they can spend money where it makes sense, using better regulators etc.
Only if you happen to have the relevant skill set. Speaking as someone capable of designing the mechanical hardware and who is broadly electrically savvy but who is most definitely not an embedded engineer: I could bang out a few hundred hacked together dev boards in week, but doing a custom board would take me a few months. Starting with reading 'Prototyping PCBs for Dummies'.
or just hire a guy that knows how to do their job.