Saturday, January 18, 2020

Makita and Rayovac Battery Pack Teardowns

It's once again time for everyone's favorite type of post!  Tool battery teardowns!  This week, I've got three seemingly identical batteries.  They've got the same connections, the same dimensions (except height - the center one is a smaller capacity pack), and so one would expect them to be very much the same on the inside.  Are they?


I assumed one thing going in, and was very much surprised when reality turned out to be something quite different!

Saturday, January 4, 2020

End of 2019/Start of 2020

Another year over.  Another year starting.  And this means yet another annual reflection blog post!

Or, in this case, "What the hell happened to 2019?"


I know the answer - he's about 18 months old and insanely active, but it still feels like the year slipped away without leaving much of a trace.  Just keeping up, not really making good headway on anything.  We had a lot going on, but keeping up with two kids took an awful lot more time than I'd anticipated.  But, I've still had some fun!


Saturday, December 21, 2019

Roomba i7+ Clean Base Teardown

It's been a little while since I did my Roomba i7 teardown, which must mean it's time for another Roomba related teardown!  This week, I'm diving into the "clean base" - the big vacuum base gizmo that sucks dust out of the bin, automating a lot of the cleaning process.  Plus, this base sits far better on carpet than the normal docking station - so what's inside?  Quite a bit!


Unfortunately, this teardown isn't just a teardown.  It's a postmortem analysis of why it's really, really important to not let this your Roomba anywhere wet - because if the clean base sucks water, it's likely to totally destroy the controller board.  Which, of course, you can't get separately.

So, join me at the end of the decade for a teardown and failure analysis!

Saturday, December 14, 2019

Building a Raspberry Pi 4 Desktop

The Raspberry Pi 4 has been out for about 6 months, and early reviews made it clear that the best option was just to sit back and wait for it to get a bit more stable.  That's happened, so now I'm going to dig into one and see what it looks like as yet another light desktop system!


My benchmarks showed that the Pi4 is a rather massive step up in performance from the Pi3 - and on paper, should outrun the Jetson Nano I've been using for a while.  Of course, I've got some of my tweaks...  so jump in and let's make a yet-more-capable desktop!

Monday, December 9, 2019

Being sick sucks.

So if you're wondering about Saturday's missing post, that's why.

I've been sick the past few days (and I basically hibernate when sick), and the kids have been varying degrees of sick as well - which isn't fun either.

I'll try to get my Pi4 Desktop post finished for Saturday and get back on track.

Question to debate in the comments: Will a 64-bit kernel on a Raspbian 32-bit userspace help or hurt performance?  I don't know the answer, and might do some testing if nobody has any conclusive data on the topic.

Sunday, November 24, 2019

Battle of the Boards: Jetson Nano vs Raspberry Pi 4 (and overclocked)

Shortly after I got my Jetson Nano up and running, the Raspberry Pi 4 came out - and, on paper, it looks like it should actually thrash the Nano for just about everything except GPU tasks.  Does it?

Actual comparisons between those two boards are hard to come by.  The internet is long on spec sheet comparisons and awfully short on real world, head to head benchmark results.  When the Pi4 came out, it had some firmware limitations that hurt performance and thermals, which have mostly been resolved by now (supposedly).  The Jetson Nano comes stock with a massive heatsink that really helps out.  So... how do things stack up in the real world?



I've got my Raspberry Pi 3B+, my Raspberry Pi 4, my Jetson Nano (with the very nice stock heatsink), and, for comparison, Clank and a few other machines.  Let's get testing!

Saturday, November 9, 2019

What Replaces 1:1 Net Metering?

One recent area of interest to me is net metering of homeowner-installed energy generation systems - and what's likely to replace it in the long term.  I'm in the process of designing a solar and energy storage system for my property, and I like to design for the long term - a 20-30 year design life of the installed hardware, with a refresh around then (hopefully) to carry the system for the rest of my life.  I optimistically have another 60 years to live, and I don't plan to move at any point in those 60 years (or, at least, will have an operating home base here), so designing long term systems is an interesting challenge.

Before wading into the waters of designing grid-tied home solar, I sat down and did an awful lot of reading on net metering, the various replacements for it, power grid issues, and all that sort of great evening reading (which I do genuinely enjoy).  There are many problems with net metering, long term, and I expect it's going to disappear within the design life of my system.  It's actively in the process of disappearing in a lot of places, mine included.  So, how does one design a system for a somewhat unknown future?  Sample the likely options and see how one's design fares against all or most of them!


Interested?  You should be!  Net metering is an important part of the future of the power grid - and how it's done has a massive impact on how sustainable power systems will be!