FUTURE BLINDNESS » personal

CNC build started

AKA — Sun, 05 Dec 2010 01:59:40 +0000

I’m building a 3d CNC mill, here is the (somewhat familiar) skeleton being assembled.

Thanksgiving brewing in NH

AKA — Fri, 03 Dec 2010 00:30:46 +0000

Dennis and I brewed a batch of 80/- ale this past Thanksgiving weekend. This is the recipe we used (the ingredients were my birthday present—thanks Dennis!). I wrote a small thermocouple datalogging sketch that would let us see the exact temperature of the brew throughout the process. Dennis made a quick graph in R:
As you can see, we were able to chill the wort quite quickly under the circumstances by continuously running cold water past the brewpot in the bathtub. The initial temperature change you can see between 170 and 180 minutes is a false reading, though, which we think happened because the thermocouple was touching the pot (which is metal and would cool much more quickly) rather than fully immersed in the wort.
After an always-tense 24 hours of no activity, the brew started bubbling away at a good pace by the time we left.

Here’s a timelapse of the brewing. It’s not too interesting. I took it because I thought we might be able to correlate the frames with temperature readings, but I never ended up setting up a good shot that would let us capture details like exactly when certain ingredients were added, etc…

Version 1, I suppose

AKA — Wed, 29 Sep 2010 18:15:16 +0000

For all the flag-flying I do for open-sourceness and collaborative prototyping/development, I do a shit job of actually contributing anything myself.

I told myself I’d publish/share my garden software once everything was running smoothly, and I had added all the features I wanted to add on the first version. Well, everyone says that, and that’s why it’s hard to find introductory, simple stuff sometimes: everyone has done it but does not feel like it’s special enough to warrant sharing it.

I am very certain that my software is not special. It is not even original, not at all. And I am a little nervous about how to allocate credit (as I would hate to take credit for the work when in fact I only very slightly modified the work of many others). Nevertheless, here it is:

Arduino-to-Pachube firmware for v1 of AKA Garden system: AKA_pachube_only_client_v3_release1

This software has been tested to work with an Arduino Diecimila (although I don’t know why any other Arduino board that can take a shield wouldn’t also work) and the v2 Arduino Ethernet board. I had a terrible, terrible time trying to get LadyAda’s older Ethernet shield working (the one with a Lantronix XPort Direct+ chipset), and I recommend you just get the newer boards with the Wiznet module. I say this because I spent about 40 hours trying to get success with the old board, and if I had instead gone outside and looked for coins I would only have had to find about a dollar an hour to make it worthwhile to just buy the new board…

The garden setup has been up and running for more than a week now with zero downtime, so I feel OK about the reliability of the circuit and the code. Next steps are:

More sensors (I am now trying to develop a low-cost, perpetually-embeddable pH sensor, as these don’t exist for under a couple thousand dollars)

Code that posts to my own database, rather than just posting to Pachube (I would like to have more features than Pachube offers for free, such as infinite-resolution histories, different graph options, and infinite streams)

Code that allows for actuation as well as datalogging; for example, to trigger a drain cycle on the system, take a photo, or adjust the lights

The Garden page has a slideshow of all my Flickr photos with the “garden” tag, and if you browse to the most recent photos you can see the physical setup of the board, shields, and sensors.

I tried hard to comment all my code and make everything intelligible, but it’s my first time letting code out into the wild so I bet I messed it up. Hit up the comments if you have questions or want help!

Another garden update

AKA — Tue, 17 Aug 2010 00:54:58 +0000

Pepper closeup

Originally uploaded by AKA MEDIA SYSTEM

After a rocky patch, the garden is doing better. This, however, is the only result of the entire operation so far. A ~200$ pepper, photograph much enlarged.
The current problem (which I believe I may just now have resolved) is that my pepper plants took off: once I installed the LED panel and set it to provide 18 hours of consistent light, most of my plants much improved. The Thai basil is still oddly spindly, and the rosemary withered up and died, but an investigation of their respective root structures leads me to believe that they were doomed to fail. The Thai basil had few usable roots at all after its potting-soil transplant (its leaves were constantly brown, brittle, and flaking off), and the rosemary had such spare, woody roots that I imagined it had been compromised long before I got ahold of it, when it was being potted for sale at the garden center.
The aphids have returned, though, and I will make a second spraying tonight in an effort to defeat them.
The real problem, though, is that while the pepper plants have really thrived, they are not producing any peppers. It is also shockingly difficult to find anywhere online that will describe what it is like to watch a pepper grow. I have worked out that the flower turns into the pepper, but all my flowers have been drying up and falling off.
In a move of reprehensible deceit, I visited a local garden store and asked about this issue, carefully implying that I had sourced the peppers from their establishment. I was told by a dull boy that I should probably have been pruning it, so pruning it I have done, this evening.
Do please leave jibes, advice, or commiseration in the comments. Thomas, I hear you! But this household is leery of worms, because our landlady would not like to hear of such a thing. (“Hydroponic grow operation” does not faze her, but I know that worms will!)

Garden takes a turn

AKA — Sat, 24 Jul 2010 18:32:41 +0000

The garden is not doing well. The pH of the nutrient solution is almost always far too acidic (no matter what steps I take to adjust it), and if one plant isn’t suffering, then another is. I appear to have chosen a poor mix of plants—that is, an environment that makes one thrive (say, causing my peppers to flower) causes another one to fail (and my rosemary immediately turns black and curled). Here are some photos from a recent five-week checkup:

I have my doubts about the mechanical efficiency of the system I am using. It has two tiny air stones at the bottom that both oxygenate and circulate the nutrient solution. However, in practice I can see that very little circulation takes place. In a test, I half-emptied the system and refilled it with a new nutrient solution (whose light-red color made it easy to differentiate from the existing solution in the bed). I poured the entire gallon of solution in one corner—the airstones run down the center of the bed, so one corner is the same as any other—after five minutes the new solution had barely moved at all.

pH monitoring has also revealed some complications that may be impeding plant growth. It has been difficult to keep the acidity of the solution down to a normal level, which I didn’t initially think would be an issue. (Not that I didn’t think there wouldn’t be issues—I just anticipated wild swings in either direction, rather than a persistent acid problem…) I’ve posted the readings in a graph below; will Google Docs be smart enough to update it every time I add a new reading? We’ll have to see. I intend eventually to use my server to publish these graphs without needing Google.

These considerations spur me to two actions: to increase the size of the system (in order to better dampen it from shocks like the introduction of new nutrient solution), and to change its main method of circulation to flood-and-drain. This will involve sourcing two larger grow beds and installing them one over the other, much like this arrangement. Flood-drain will, I hope, circulate solution much more efficiently and get more oxygen to the roots. It is also convenient that flood-drain is also the eventual system we’d like to have running when we try adding an aquaculture element to the system.

I have also added a grow light to the setup, and have (but have not yet set up) a large solar panel and charge controller. More about these next time.

First seedlings started

AKA — Fri, 18 Jun 2010 02:51:16 +0000

I enjoy hobbies, and this one seems fun—I can combine my interest in resiliency, my love of cooking, and my pleasure in experimenting with code and hardware.

Thai basil seedling in expanded clay medium

I set up the garden kit this evening and transplanted three seedlings: rosemary, chive, and Thai basil. I’m using this system to begin with (I’m not a good gardener, so I needed all the startup help I could get) but the plan is to use this setup to learn the processes and then make a larger-scale, more complete system when I have more room.
The current system is smaller than most—especially if I were to try to add the aquaculture element now. Murray Hallam, who seems to know what he is doing, says that smaller systems are much less stable, prone to large swings in state. Part of the reason I’m going to try to monitor and automate this process is to get faster, more precise access to the state of the system.

Protected: Thesis done

AKA — Wed, 19 May 2010 23:15:02 +0000

3d printer finished

AKA — Wed, 03 Mar 2010 20:57:55 +0000

More details soon.[Gallery]

3-d printer nearing completion

AKA — Fri, 19 Feb 2010 18:54:38 +0000

Andrew2.0 and I have been working on building our own RepStrap for the last three or four weekends, and last night we had a very successful first run (without the extruder installed). Above, you can see a video of it in action. (Thanks for the FlipHD, Dad!). We made some initial measurements of its alignment and were pleasantly surprised to find that the X and Y axes are just about perfectly square to each other, and even with our hardware-store threaded rod we seem to be getting accuracy to about 0.02mm(!)

We’re assembling and mounting the extruder head tonight, so by early next week we should be printing in ABS for real. It’s pretty addictive building these, partially because it’s awesome to build something that is so much more accurate than a person can be.

New Year

AKA — Mon, 25 Jan 2010 19:21:34 +0000

Yellow sapphire on white gold

Get ready for a characteristically uneven spate of updates. First and most important, I convinced Harlo to get engaged! It was on New Year’s Eve. The original plan was to meet at the Bravest, a bar where we used to hang out after work. I had the evening so meticulously planned and was so cunning that, in fact, I forgot to tell Harlo that she was supposed to meet me there.
So, Plan B turned out to be meeting her at her doorway and giving a wonderful speech about how much she means to me, and how I can’t wait to grow old with her. I had been in the car driving down from Boston for a very long time, though, and had drank a lot of Diet Coke in my nervousness, so I really had to use the restroom. I don’t recall, um, the full speech I managed to perform, so you will have to ask her.
After convincing her that this wasn’t a joke, she said yes, which set the tone for the evening’s celebration.
After a strange, fancy dinner cooked by a roommate’s boyfriend, we headed to a wonderful nameless place on 5th street between A and B; we had previously rung in the New Year there and loved it because there was very little fanfare—just a quiet little place where it might not even be a holiday. A great number of our best friends were able to make it to the celebration, and we had a lovely time. Also, there was a dog who was trained to play pool!