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Got Some Soldering Done

Posted 2012.08.14 8.20 in Computers/Internet/Technology

This past weekend I got the new version of the ISEB-6 mostly soldered out.

It all went together fairly easily, with two unfortunate exceptions. The BMP085 barometric pressure sensor, and the HMC6352 magnetometer/compass. Both components are surface mount ‘leadless chip carriers’ – and both proved harder to hand-solder than I expected.

The thing is, unlike the ATMega1284P which is a TQFP-44 or the few SOT23 parts — all of which have ‘pins’ sticking out (albeit tiny pins), the two aforementioned sensors are in LCC packages where the connections are all underneath the part. There’s nothing visible from ‘above’.

I had some tricks in mind to solder them, and the tricks failed. In the end, I unfortunately destroyed both parts. Boooooo. Fortunately I did have a spare BMP085 laying around, but the HMC6352 is kinda-expensive and I didn’t have a spare.

Also-fortunately, I had a backup plan for soldering these tricky parts – hot air. I have a Sparkfun Heaterizer XL-3000 which I hadn’t actually used before. It did the trick though, allowed me to remove the dead parts without destroying the rest of the ISEB6 board, and I was able to solder the new BMP085 with it.

When I get a replacement HMC6352, I’ll use the Heaterizer once again to get that in place.

After that, the next steps will be to assemble a new leather bracer, and then build it out, with all the peripherals.

The Good, The Bad, The Ugly

Posted 2012.07.12 10.10 in Computers/Internet/Technology

So twelve or fourteen hours into playing with my custom circuit board for the ISEB-6 Mark II, and I’ve been compiling a list of the things I did well, the things I did poorly, and the things that were just plain dumb.

The Good:

  • It ‘works’, more or less. That is, the uC functions, I can upload programs to it, and it accepts and runs them.
  • The screen works. This is more than just a hardware thing, as I had tweaked the library to use hardware SPI rather than software SPI, to get about a 50% bump in speed, and this was the first test of that library mod that wasn’t on a breadboard.
  • The buttons and indicator LEDs work.
  • The LiPo charging circuitry works.

So all in all, there’s some legitimate successes there. On the other hand, there’s some oopses too. Somewhere between submitting the board for fabrication, and actually receiving the boards back, I started to realize my mistakes. Having the board and testing it, confirms some suspicions and adds new problems to the list.

Starting Over from Scratch

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Time for Tourism

Posted 2011.04.26 17.44 in Uncategorized

If you’re looking for somewhere interesting and off-the-beaten-track to visit, maybe consider touring scenic Pripyat?

Ok I’m being a little bit tongue-in-cheek but in actual fact, this is something I would probably enjoy seeing. There’s a lot of history there, frozen in time for the past 25 years.

Here’s a photo that was taken almost exactly 25 years ago, give or take a day. I don’t want to think about how much radiation the photographer absorbed in this fly-over. Even today, visits near the plant involve radiation dosimeters and close monitoring.

Still, it would be a fascinating place to visit.

Reminder about Safety

Posted 2011.04.09 18.16 in Hobbies, Pointless Blather

I’ve been pretty good about doing the safety goggles thing when it comes to playing with lasers. But for general electronics work, it’s just never occured to me that they’re necessary. I mean, snipping component leads, working with solder, even some mechanical stuff like drilling or cutting enclosures… it just didn’t seem that dangerous.

Then, cutting a little hole in a plastic enclosure for a switch, and ZOCK!

Tiny metal fragment, right in the eye!

It came off the edge of the blade – a tiny little fragment of the cutting edge of an x-acto knife, straight into the right eye! Ok, now I suddenly recognize why safety glasses are a good idea even with simple electronics.

I was able to spot it with a mirror and a bright light, but couldn’t get it out – it was too tiny and looked like it was sort of stuck in the white part. Then I blinked and it ‘vanished’. Now I don’t know where it is… I suspect it’s lost in the conjuctiva under my eye.

Now my eye is vaguely itchy but I’m not sure if that’s from the metal chip or from me poking around in there trying to find the metal chip.

So anyhow, let this be a lesson — eyeball safety, is always a good idea!

Broken Pen

Posted 2010.09.14 21.13 in Computers/Internet/Technology

Now this time, it’s totally not what you think! I didn’t break it — I took it apart to fix it.

Honest!

See, I have this Wacom Bamboo Tablet for doing drawing on the computer. I’ve only just started playing with it a couple weeks ago. But I don’t have enough desk space to keep it out all the time, so when it’s not in use, I store it in a ‘cubbyhole’ in the hutch on my desk. So far, so good.

The tablet has a pen. The special pen that makes the tablet go. The pen is all full of delicate electronics, but it’s very lightweight, and rolls easily, and is not attached in any way to any thing…

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Playing with Chemicals

Posted 2009.09.06 17.51 in Hobbies, Pointless Blather

I remember back in high school, I think it was grade 10, when the science teacher banned me from doing experiments. Whomever I was partnered with, got to play with the chemicals and I had to take the notes. It seemed terribly unfair, although it probably saved the school some money and agravation.

Though I maintain to this day that it wasn’t my fault — the textbooks simply should not ask “What do you think will happen if you…?” unless it’s something they realize you might try. After all, it’s science! Empirical data beats speculation hands-down. Why wonder what might happen, when you have the vial in your hand and the beaker on the desk? Just find out!

But I digress.

Having recently got my hands on some chemicals for developing black and white film, and having some colour film laying around, I decided I wanted to find out just how ‘well’ the two would mix. I’ve read that you can process colour negs with b&w chemicals, but I’ve also read that it’s tricky and takes a lot of trial and error to make it go.

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