The majority of US homes use a split phase setup. So 240V is readily available and in fact the only way you can run central AC. Nominal voltage of a single phase is 120V. Technology Connections has an entire video about it.
One example from the software side: A common thing to do in data processing is to obtain bit offsets (compression, video decoding etc.). If a byte would be 10 bits you would need mod%10 operations everywhere which is slow and/or complex. In contrast mod%(2^N) is one logic processor instruction.
I find hand soldering QFN is faster, easier and more reliable than (T)QFP once you got enough practice. If you need to rework the QFN part the key is to FLOOD the footprint with good solder flux from a syringe. Do not use one of those flux pens, those do not dispense enough flux.
> If you need to rework the QFN part the key is to FLOOD the footprint with good solder flux from a syringe.
I've never tried this but this makes a lot of sense in my mind's eye. I'll try this next time I have such an issue.
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TQFP seems nice because I can sloppily shove tons of solder down, and then just wick up all the excess solder with solder wick. In fact, I purposefully over-solder all the TQFP joints for this practice. (Too much solder during reflow, and then just a quick cleanup step with a soldering iron later).
I concur, bought insurance for a new car early January and got it instantly using esurance.com (Allstate) by just entering my VIN. Yes, I am in SF/Bay Area.
interesting. i forget if it was allstate or state farm but one of them refused to do online and also refused to do fewer than 14 days out - this was like two days ago.
To be clear: I already had my old car insured with them for several years, so I just removed the old car and added the new car. I am also 50+ with no negative record and a garage in a single family home.
Ok, I'll bite. Uploaded my gerbers using https://instantdfm.bayareacircuits.com/ Site does not respond for 10 minutes+ which is is not a good start. It's instant on the Chinese sites.
Quote for 100 boards (ENIG) on Bay Area Circuits, 10 days lead time, excluding shipping: $1000 ($1244 for 5 days lead time)
Todays quote for exact same 100 boards (ENIG) on pcbway.com, _including_ DHL shipping cost, 2 days lead time: $148 (shipping to Bay Area is usually 2 days with DHL, so really 4 days lead time). I've never had any quality issues and my boards have fine pitch 0.4mm BGA parts.
Yeah no, not even close. Certainly not marginally higher.
It's slightly cheaper than oshpark.com, they want $15 a board.
I do this all the time. OP is talking about of their ass.
China is dramatically cheaper than domestic.
If it wasn't for the DoD requiring all military parts be domestically manufactured, there probably wouldn't be a board house (or metal fab) left in the US.
And that is domestic versus imported. In Shenzhen they do production of smaller quantities in 12 hours overnight for $30 extra with local express delivery.
I hung out with a friend of mine in Shenzen who does this stuff all the time (and is Chinese not that is super important other than the fact being fluent helps a ton).
Together we prototyped a product over a 2 month period, him handling the HW and EE bits and me writing the board firmware and HIL simulator/test-harness.
We would get some boards, he would find and correct any issues with the board, get a new file to the board house before 5pm and we would get new boards in the morning at 9am delivered by a motorbike courier for about $20 or something. As a software guy that seemed pretty insane to me.
All up we probably did about 6 or 7 HW revisions like that and a few of those probably could have been avoidable if more care was taken but why would we when it's so cheap to iterate so quickly?
Unfortunately for various reasons we didn't choose to continue the project but I learnt a hell of a lot and really enjoyed hanging in Shenzhen and getting to understand the hacker culture there a bit more. We burnt overall a pretty small amount of money to learn some important lessons that I think would have been much more expensive anywhere else in the world.
If you every write more about it, please post a link here in HN, I'm sure tons of people would be interested in more details about the what, why, how of what you were doing, and life in Shenzhen.
I haven't used pcbway so maybe they're much better, but I can say that messups and throwaway board issues are common enough with JLCPCB assemblies that their "sorry, here's a $5 coupon" response is a meme in hobbyist communities. They're very hard to trust for anything truly complex or critical.
I’ve heard very positive things about pcbway. I use JLCPCB regularly for fab and assembly. Most issues I’ve had come down to misunderstandings due to problems in their web order PCB viewer, which can be slightly janky. I have however learned to use it properly and I don’t have that type of error anymore.
As far as PCB fab or PCBA quality issues, I’m unable to think of any problems I’ve had across 15+ orders over the last three years. I just got another two PCBA jobs back in the last couple weeks and they were great.
I’m honestly in awe of what JLCPCB does and it’s a big inspiration to me for how much better things could be in the USA if we were committed to manufacturing.
The short answer is yes. The long answer is that most of the VideoToaster software and hardware were specifically designed for the Amiga hardware architecture and therefore did not easily port to other systems. The extension card was Zorro II and the performance critical software was written in 68k assembly. In some cases the assembly code is written in such a way that it depends on cycle exact sync with the video signal. Original source code is on github.com, search for OpenVideoToaster.
If I recall correctly the original video toaster, and I believe even the revised toaster 2000 and 4000 all occupied the video slot, a dedicated internal interface that provided direct access to analog RGB component signals as well as some other video timing and audio channels. There was no connection to the Zoro II or later Zorro III system buses. The Amiga 4000 video slot added digital rgb counterparts to these analog signals, and also some oddball 8 bit connections to,I believe the parallel port UART pins.
You can buy Prusa MK3 kits from Aliexpress for half the price of the original. I bought a kit from Prusa and one knockoff from Aliexpress. Parts wise they are 100% the same and perform the exact same way. Do I feel bad about it? Kind of. The Chinese seller certainly did not put R&D into any of it. And being in China makes sourcing much easier.
Yeah, I've bought a knockoff on Aliexpress too, but mine was not a 100% clone. I bought a kit that came with the Bear upgrade and didn't come with the parts that would be replaced during the Bear upgrade. Those are the ones I think are hard to define without being vague. My worry is that by adding vague and all-encompassing restrictions, the license will no longer be free.
The question is not if Rust is more expressive but if C is expressive enough for the Linux kernel. So far there is no evidence that Rust adds any value here. And if C is missing certain features, they can be added. It looks like ISO is looking at that very thing in C2x and beyond.
C might be enough, but Rust is better.
Rust makes programming more productive. Are you denying that?
And C is not going to get Rust features: C's philosophy to stay limited on purpose.
