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So. Many. Wires.

Posted 2010.12.31 18.58 in Computers/Internet/Technology, Hobbies by Stephanie

The DIY Thermostat project hasn’t gotten as far along as I had hoped. Or, it has moved forward in leaps and bounds. Depends on how you measure progress, I guess.

I haven’t started building the finished project, it is still on the breadboard. However, I’ve expanded the breadboard to include all the working parts, i.e. the finished button layout, and the relays that will control the furnace and air conditioner.

I’ve also changed plans, in terms of the communications.

I was originally working with Bluetooth, and indeed had a working prototype with a bluetooth module. I wasn’t too happy however with the BT functionality. It was not that reliable, I found — as in, being able to ‘guarantee’ that I could connect to it every time, automatically, any time I tried. There’s that messy handshake business, with PIN numbers and stuff, and that seemed to be a hang-up.

Also, ultimately it would have been paired with my server which is Linux, and there seemed to be more issues there, getting the paired connection and the PIN numbers and blah blah blah. It was looking aggravating.

My plan-b was to use a different wireless scheme, the XBee modules. These looked attractive in that at the computer-end it would just be a usb-serial port, and would be always connected. However, there were some cost issues (It would have run about $100 for the modules etc. to achieve what I wanted) and again, no guarantee of 100% reliable connectivity.

So on to plan c. Good old safe, secure, and reliable ethernet. Getting from wireless to wired didn’t happen in one step. I was also dealing with the power requirements my Thermostat had. I didn’t want to have to constantly feed it batteries, and my design looked like I was going to need 3 or 4 AA batteries to fully power it. So I was already starting to accept that I would probably have to run some extra wires into the thing, to provide 5vdc.

With that on my mind, and looking at the communications options, I realized that I could solve both the power and comms issues with a single Cat5 line. Power over ethernet. I can use mode B, grab one of the unused pairs in the Cat5 cable, and pump the power in there, from my switch. Then at the thermostat, I just tap the power pair and run it through a regulator and hey presto, 100BaseT link, and power too!

Here’s the new version of the prototype, breadboarded with the relays, switches, and — yeah, that’s an ethernet port up there on top.

So the next step (again) is to start building all this into the finished project box; moving it off the breadboard and into the final package. Also, there’s some more coding to be done, to get the ethernet comms working right.

I can’t build a complete web server into it — not enough space left in flash or ram. I’ll create my own little thermostat protocol and then create a web interface for it on my home server. And the iPhone app that I will be creating. 😉

End of the Year

Posted 2010.12.31 18.19 in Pointless Blather by Stephanie

So 2010 is drawing to a close in a few hours. It went by quickly, except when it was going slow. There were ups and downs. Mostly downs. All in all, I’d rate it about a 4. Solid “Meh.”

Nearly adequate.

The Gakkenflex

Posted 2010.12.26 18.57 in Hobbies, Photography by Stephanie

Last week I assembled the Gakken kit # 25, the Gakkenflex Twin Lens Reflex camera. It was a pretty straight-forward assembly, the Japanese instructions are well-illustrated enough to get by, although there are some English translations around for the assembly.

As cameras go, this fits in the ‘toy’ category, next to other plastic wonders like the Holga or Diana. The lens is a simple plastic meniscus, the shutter is single-speed (about 1/125 allegedly) and there is a single fixed aperture (said to be about f/11). The focal length is roughly 40 or 45mm. The Gakkenflex takes standard 35mm film, and is actually very small and kind of cute in person.

Winding is manual of course and there is no frame counter, just an indicator to let you know when you’ve moved the film far enough for a single frame. Unlike the Holga, the Gakkenflex actually has a focus-aide! As a TLR, you are looking down onto the focus screen, and adjusting the twin lenses, so when it’s in focus on the screen it is (supposed to be) in focus for the film.

As with the Holga, the shutter release is not connected to the film advance, so you can take double-exposures, on purpose or accidentally. Finally, the Gakkenflex has a tripod mount (on the side of the body, so you mount it sideways) but there is no provision for a flash. None at all.

I rushed a roll of film through the Gakkenflex to see how it would go. As expected, the plastic lens gives a ‘soft’ look to the shots, and  you can get some Holga-like effects by playing with double-exposures and other ‘artistic’ errors.

I quite like the Gakkenflex, although the first batch of shots won’t win any awards. Maybe if I spent more time outside and wasn’t in a hurry to ram film through it… Oddly it also makes me want to blow the dust off my Holga and play with it some more too. The Gakkenflex has the advantage in cuteness, and if you don’t have a cheap source of 120mm film then the Gakken wins there too for using standard 35mm film.

As usual with kits, 80% of the fun for me is in the building.


Posted 2010.12.23 9.43 in Computers/Internet/Technology by Stephanie

Last night I got the bluetooth wireless module hooked up and tested it out. It works! My prototype thermostat can be wirelessly queried and controlled!

The bluetooth module is the little red thing at the left edge of the breadboard. It talks serial to the microcontroller and talks wireless to the computer. As far as the computer is concerned, it’s just a standard tty serial port. It’s fairly seamless!

In the above screenshot you can see some debugging info that comes over every 15 seconds, plus I sent the ‘run program’ command (rp) and the DIY Thermostat responded accordingly!

Geeky techy stuff below the fold.

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Joyous Yule

Posted 2010.12.21 10.05 in Computers/Internet/Technology, Spiritual by Stephanie

It’s the Winter Solstace today. [sarcasm]Yay, winter.[/sarcasm]

Also, this:



Posted 2010.12.20 21.01 in Hobbies, Life On Drugs, Pointless Blather by Stephanie

No posts for about a week here – I’m feeling rather scattered. Hard to believe it’s about 2 months since I got off the cryptospam. The side-effects / withdrawal symptoms have all but left finally, but that still leaves me with just the depression.

I’ve been trying to deal with that by forcing myself to be active, getting back into some of my old hobbies, like electronics. It’s difficult though, trying to get the interest or enthusiasm up. I think it’s a bit like when a kid is forced to do some activity by the parents, you know? Piano lessons or soccer or whatever… the kid doesn’t really want to, but grudgingly goes along with it because they have no choice. I think it’s like that, only I’m playing both roles.

This has led to me being a bit frantic and scattered. What I mean is, I know I’m supposed to be doing something but don’t necessarily want to do whatever I may have started yesterday, so today I try something else. Then there’s shipping delays and stuff so I’ll order some electronics kit, and before it arrives, I’ve gotten interested in six more things — and potentially ordered or bought them too, in the meantime.

Ontop of all this, it’s the stupid-season (season’s greetings) and that brings all sorts of additional baggage and issues. What a time to kick the anti-depressants, right? Always a joy at the x-mas parties, too: “Hi, haven’t seen you in ages. How have you been?” “Well, I feel like crap and I’m thinking about hanging myself from that tree over there. How about you?”

So I’ve got a lot of half-built half-finished half-thought-out projects on the go, and if I’m not working or trying to sleep, I’m trying to coax myself to “have fun” with a project. Today I’ve been working on my DIY-Thermostat.

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Blinkin’ Flashin’ Bliss

Posted 2010.12.15 0.57 in Computers/Internet/Technology by Stephanie

It’s a problem I’ve confessed to before. I love blinkin’ lights. LEDs, blinkins, flashins, flickering their magic little messages… and just recently, I’ve come across a wild and wonderful blinkin’ flasher that’s just plain blissful blinkin heaven.

Not only does it enchant and calm with it’s blinkins, but it also performs fun mathematical calculations. See, it’s based on Conway’s Game of Life.

It’s a GoL kit – modular boards, each with a 4×4 grid of cells (represented by LEDs). The boards can be linked to build larger and larger grids. I’ve started with 6 boards, for a 12 x 8 grid. It’s very addictive though. I already want to get another 6 boards and go to a 16×12 grid.

Here’s a short animation – it’s not perfect, there’s missing evolutions so the animation doesn’t exactly portray the way the game runs. But it’s close enough: a bunch of (seemingly) random flashes of LED light.