While it's a fascinating project I'd have some security concerns about plugging someone's USB business card into my computer.
More seriously, I never managed to understand the "obsession" with ROHS (this here is just an example):
>I made sure to have a lead-free process—the boards, parts, and solder paste are all RoHS—so that I wouldn't feel bad about giving them to people.
I mean, you are creating something that (besides being very nice) is not needed, that very likely will end soon in the trash (and that contains anyway a few grams of "far from clean" materials) and you worry about the tiny amount of lead in the solder tin?
How else would one do forensics?
"Ah-ha!"
Reference:
More considerate would be to provide the card in a protecting sleeve (that would protect from all the bad, bad substances it may contain) or just use a good, ol' plain paper business card, posibly printed with "bioetical" ink.
You get it on your hands and then ingest it when you eat. (People don't usually wash their hands after touching a business card.)
I was referring to the parent poster that talked of people putting them in their pockets.
Anyway, ROHS (or lead-free) is a good thing, but it is not like you get lead poisoning (or saturnism) because of the once in your lifetime you touched sometthing contained lead and then - if you eat with your hands - you managed to ingest it:
https://en.wikipedia.org/wiki/Lead_poisoning
You need to drink from lead or lead soldered tap water or water contaminated by lead to become poisoned by lead.
In the case of the Linux business card the exposed surface that would eventually contain a minimum amount of lead - pre-ROHS soldering tin contained in the common eutectic Sn-Pb alloy 37% lead - is in the below 1 square mm range.
You would nead to actually lick hundreds or thousands of such cards to ingest any meaningful amount of lead.
And lead free soldering tin may contain (in minimal amounts):
https://en.wikipedia.org/wiki/Solder
bismuth and antimony.
I will forever feel guilt about letting him play in the yard as a baby (my best guess as to where it came from) and take other efforts to reduce the lead in his environment.
Depending on your life situation, it may be impractical if not impossible to reduce the lead in your environment. I am open to being further educated on this subject, but it seems like reducing lead in all products that will be handled by people is a net benefit for getting to home environments that will not cause brain damage to the infants that live in them.
Right, but how are you going to put it in your pocket without touching it with your hands?!
>You would nead to actually lick hundreds or thousands of such cards to ingest any meaningful amount of lead.
Lead poisoning is cumulative, so you want to avoid ingesting even very small amounts. I doubt that good data is available regarding the amount of lead that would be ingested in this scenario or its potential effects. Best to be cautious. Lead free solder is not expensive.
In any case it is safe to touch, despite the people downvoting me:
https://www.quora.com/How-dangerous-is-it-to-hold-a-block-of...
HASL is perfectly usable with stencils, in my experience.
As you say it is just a matter of slightly increasing the soldering iron temperature, but it doesn't end there and there may be issues further on (JFYI):
https://en.wikipedia.org/wiki/Whisker_(metallurgy)
It seems like lead-free alloys tend to be more problematic in these - fortunately rare - cases.
But because it is more than 15 years that ROHS came in force, I read in 2019 "and I made it lead-free" like I would read "and I buckled my safety belt" or "I put my helmet on", etc. I see it as "the normal" way, nothing worth a mention (nowadays).
Very possible, there are a number of (pretty much wide) exemptions even in the last version:
https://www.gov.uk/guidance/rohs-compliance-and-guidance#wha...
Good to see you here, congratulations for your idea and creation.
I replied to that in another post, ROHS is 15 years old or more and most available parts and solders are ROHS compliant, I believe you would have had a tough time to intentionally make something that was entirely non-ROHS compliant.
Lead causes permanent brain damage in children. There is no detectable amount of lead in the blood of children which is considered safe. While an adult body absorbs roughly 95% of lead into its bones, children's bodies end up storing lead in blood and soft tissue where it causes damage. When untreated, it can take months for lead to exit a child's bloodstream.
I would never consider reducing the lead used in something I've built to be wasted time.
Is it safe for children to solder with leaded tin? (Many people here did so as a child, I suppose)
I used lead based solder as a child, and I turned out okay. That said, people used to use pewter plates and got sick from lead poisoning after eating tomatoes (the acid leached the lead from the plate); Roman soldiers would keep their wine in a lead container to sweeten it; pretty sure I've heard something about people painting their houses with leaded paint as well. On the one hand, society survived all that. On the other hand, if I have the opportunity to not risk poisoning a child by spending a couple extra dollars buying solder, that seems like a pretty easy decision to make.
Seriously, please choose lead-free.
Pregnant women weren't allowed to eat in the cafeteria due to the high number of miscarriages. The people inhaling the stuff all day... let's just say that had a reputation among the other factory workers for being a bit mentally challenged.
This is the responsibility of the creators of the USB hardware, firmware, motherboard firmware, electrical design, OS developers / driver developers.
It should be safe to plug in a USB device by default
In practice it can be safe on multiple levels. He could’ve also just put some malware I. A pdf or word document, as word is what recruiters want.
USB-C's midplate is specified at 0.7mm, and all of the cheap chinese PCB manufacturers only offer 0.6mm and 0.8mm. 0.6mm is too thin to make reliable contact with most of the cables I've tried: I haven't gotten around to ordering another batch at 0.8mm, but plugging the corner of a 0.8mm M.2 SSD into a USB-C cable, it's pretty (i.e. probably slightly too) snug. Thin PCBs are also extremely flexible, which isn't great for brittle solder joints, ceramic capacitors, etc.
When I first got my MacBook Pro, I just got USB-C cables for my external monitor and my (USB-A) hub. That was very cheap, but I love the convenience of Thunderbolt and shelled out the cash.
Having said that, I will say the USB C connector on my phone is far superior, as I plug/unplug it daily.
Power and bandwidth aren't even related to connector type.
You shouldn't need to remember orientation or look at it! You're apologising for a bad design.
> Power and bandwidth aren't even related to connector type.
Not true! For example the max bandwidth you can currently put through USB-A is 10 Gbps with USB 3.1. Through USB-C it's up to 50 Gbps with Thunderbolt 3.
Edit: I remember something, having done work related to embedded stuff. About 6 years ago, we still had 3.5" floppy drives in a couple of scopes in the lab. We replaced those with a device that internally had the interface of a 3.5" floppy drive, but on the outer faceplate it had a USB-A connector for thumb drives.
That means you need to create A peripherals if you want the largest audience.
Practically, since you can find them as you say, is that as a peripheral vendor in the west, you can't ship a C device with a C to A plug because you'll lose your license.
> It has a USB port in the corner. If you plug it into a computer, it boots in about 6 seconds and shows up over USB as a flash drive and a virtual serial port that you can use to log into the card's shell.
The parent of this thread has a valid point here and the insecurity implications of this is nefarious if one isn't careful.
While it is a technically cool fun project, I can imagine a bad actor taking this to DEFCON/CCC or even a tech-centric concert and mass producing this to emulate a USB drive, but is also a keylogger or a remote access tool of some sort which reminds me of the nightmares of BadUSB.
Now, where is the predictible sandboxing guy to counter your predictible "security implications" argument?