perjantai 27. tammikuuta 2017

Are you 'Full Stack'?


This occured to me awhile ago. Everyone seems to be fixated on full stack developers. But what does that phrase mean, exactly?

Most common approach I've seen is that you need to master server- and user-side things. Which, granted, is pretty common application these days. You've got a server (or cloud of servers) and user (often a phone), and you've got write the software for both.

'Both' here is pretty ambiguous term, but really, it isn't just that easy. There are loads of skills that you could list on both ends. Server maintenance, databases (very likely several of them, depending on clients' neds), programming languages (also several, both server and client-side), web user interface (html, css, js, libraries..), mobile user interface...

But wait, is there something missing here?

How about this IoT - Internet of Things - stuff? Where does this sit on this "full" stack?

As it seems, it doesn't.

Granted, that might be beyond most applications, but it also gives me this warm, fuzzy feeling of superiority to know that at least there I'm easily beyond what's understood as full stack. But then again, jack of all trades etc etc. I can, if needed, work on any level of said stack. The thing is, it seems that everyone wants to be on the "top" of stack while I enjoy staying close to the metal anyway.

</not-so-humblebrag>

Oh, and when I say "close to metal", I do mean it:







keskiviikko 25. tammikuuta 2017

Automotive fuses


Some time ago I posted about interesting looking fuse holder I was considering to an application. At the time I found out that these aren't really rated for high voltage applications.

Now I was browsing fuses again and this little thing turned up:


Whoah, that actually looks like something I could use.

Except that those small automotive fuses aren't really rated beyond 80V DC (and typically no AC rating at all). So what good is holder with 250v rating (both AC and DC) when you can't get similarly rated fuses easily?

So I'm still looking...



perjantai 13. tammikuuta 2017

Climate change isn't real!


Sorry, title should be in quotes.

Another equally common quote is "we [the humans] aren't causing it!"

If you believe either of above, take a look at this graph below. I know, It's huge, but humor me here and scroll all the way down. No need to read everything, just follow the graph on the way down.


Now, scrolling down, did you, at any point earlier, see as large change as during last hundred(-ish) years? (that's the solid black graph at the very end).

I was pretty sure about climate change before, but when put in this way, it really makes the point. The change here definitely isn't due to any natural causes - it's us. No point trying to argue or deny it. And we, all the humans here, absolutely need to do everything we can to minimize the impact. After all, the change that has already happened here is way too large to leave us with only minimal impact.

Credit where credit is due, this is borrowed from xkcd here.



maanantai 9. tammikuuta 2017

Demise of component catalogs


These says the thick - no, huge component catalogs from various distributors seems to be dying breed, being moved to the net. I do understand that there are huge amount of different components and not all can be included in a book, but sometimes even one or two of a category can be enough.

For example, I happened on picture below just earlier (source).


This gave me an idea on a project I was working on, but I already had suspicion that it wouldn't work, at least not by going by the book. But I went to a distributor site (which shall be remain unnamed but people my) and tried to search for a fuse holder (third rephrasing of query, first two resulted nothing useful). And got this listing:

Screw that, half of it seems completely wrong and by experience I guessed other half would be just a red herring anyway. These sites pretty much always use very literal search which is great if you know what you are looking for, but when you only have a vague idea of what exactly you want, is completely useless.

So I grabbed my by now 10-years old, 1000+ page component book and started browsing. And found the similar holder in a few minutes. As it turns out, my first suspicion was correct - automotive fuses (and their holders) as pictured above are rated only for low voltage applications so I have look for another kind of protection anyway.

Now, even with this known, just finding the similar holders in the component book gave me exact component code to look for, which allows be to trace back to correct category in the net to see full listing of holders - which is what I wanted in the first place anyway.

But for how long, I wonder - as the book I have is already 10 years old and as far as I know, no newer editions exist. Which is sad as browsing for suitable looking components in a printed book (with pictures) is always faster and easier than trying the same in the internet. Even when you have to go to the net for details in the end anyway.





sunnuntai 1. tammikuuta 2017

STM32F469 USB working - once again


Okay, I've got USB working again on the STM32F469 now. Kinda. There's still something funky with the descriptors preventing it from working with Windows properly, but with Linux it works pretty nicely now. There's more pressing issues at the moment so for now I've postponed further studies as my board works well enough not to be show-stopper (as in: requiring layout changes) later on.

What I did was to take newer STM cubeMX firmware and adapt it to my use. It took a while but eventually I got it working (at current levels) with my expected configuration - STM32F469 MCU, OTG HS port/core and HID firmware. It's nice to be driverless.

I still have no idea why the older USB drivers don't work at all. It's like USB subsystem is never initialized properly, it just doesn't do anything with 469 MCU. No interrupts, no activation, nothing. But as the newer one works, that's kind of irrelevant at the moment.

Now, whether I post new(er) drivers - well, I don't really know yet. I'm pretty busy and polishing current mess to release-able niceness takes some time. Also 469 Discovery board doesn't use HS port so those are not useful there (alhough they might with with FS port too) , but they might help some people. If you are interested, let me know.