Aquaponics Cherry tomatoes

Those crazy cherry tomato plants I have growing directly in my fish tank water are producing some really nice fruit.

This bunch looked like a likely candidate for some photos so here they are...

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Photography Camera hacking

Ive bought a new camera!

But more importantly for right now, my old camera didnt focus any more, so I thought I might pull it to bits to see if I could fix it.

A camera hack if you like.

Well its hacked now.

But in the process of attempting to fix it, I thought it might be grit or something stuck in the focus gears. I figured I might be able to override the emergency shutdown on lens fail, and just use brute force to get past the grit.

But before pulling it apart I thought Id look for a software hack to manually focus the thing. Its a Canon Powershot A490 point and shoot (or at least it was), so it doesnt normally have manual focus.

I found much more than a focus hack, but also much less.

Much less in that I still couldnt do manual focus, but so very much more in that I found CHDK - Canon Hack Development Kit.

CHDK is amazing. Its a kit full of files that you install onto your SD memory card, put it into your camera, then use the update firmware option (only seen on my camera when the CHDK is on the card) of your camera to install all the new functionality. It does things like...

• motion detection
• increment focus to automate focus/photo stacking as mentioned in the previous post
• depth of field calculator
• exposures from 2048s to 1/60,000s with flash sync
• change the layout and visibility of you on screen display info
• etc etc etc (so much more)

Look here to see a slightly bigger list, but still not all of it.

And here for the manual which covers more.

But even more can be found on the forum in the form of scripts that can be loaded into your camera. There are scripts that do motion detection fast enough to catch lightning strikes. (less than 60ms I think it was - dont quote me)

So in spite of just buying a new camera, Im off to see if the $20 camera I saw in the electronics shops bargain bin is a cannon powershot. 

120 Things in 20 years CHDK camera hack - Awesome. 

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Photography New to me Canon EOS 20D camera

My new camera is a lot like my old camera in so far as they both take pictures, and they are both 8 megapixel cameras.

But after that they diverge a bit.

The Sanyo Xacti that Ive been using for the last 1300 photos Ive taken was gifted at me by someone (Thanks anonymous company) when I really needed a replacement because all the point and shoot digital cameras Ive bought to make this blog (I think its 3 now) fall over just after 5000 happy snaps.

5000 seems like a lot when I put it in print, but in terms of time, that equates to less than a year per camera.  Sure they cost less than AU$100, but I still want more than a year out of anything I buy.

This one that Ive been using is still going strong, and does a pretty good job of it I suppose, but I found the interface very heavy going.

It has quite a few options and features, but all of them have to be accessed via a clunky multi-level menu system. That means that every time you want to do anything other than what its set to do now, you have to explore a stack of menus to finally find what you need, and by the time youve found it, the ladybird has finished eating its aphid, and flown away.

My new camera on the other hand is a zillion times better to work with. Ive only had it for around 10 hours, but it already feels comfortable.

Its taken around 1200 pictures so far in its life.

I have very greasy fingers.

Im eating zucchini and haloumi fritters.

Delicious.


The new camera is a Canon 20D. It was originally sold for around AU$1500 (Australian dollar) in 2004, and was described as a "semi-professional" or "prosumer" camera at the time, which of course means substantially more than other imaginary words and their associated imaginary metrics.

But on the whole, the camera rocks.

Thats my official rating out of 5.

It has a 4 GB CF memory card, which is the size of a bulky circa 2012 64GB mp3 player, and that cost around the same as a bulky circa 2012 64GB mp3 player. It takes a while to transfer photos, but it has very nice functionality, and best of all has an interface that works.

It also comes with some nice lumps of glass in the lens. It seems to be the lens that lets down lots of little point and shoot cameras. The quality of the photos taken by my new 8 megapixel camera is a lot better than those Ive taken with an 8 megapixel point and shoot style camera.

The second lens feels a bit like it might blow away, but at $10 its a very nice thing to have around.

The camera came with a Canon 18-55mm f3.5 image lens, with image stabalizer. Ive just discovered I love image stabalizing. Image stabalizing allows you to be a bit shakey, and have the lens do some stuff to fix it.

As I understand it, there are exactly two ways to do image stabilizing.

• 1. Project an image onto the censor, so that the image is a little larger than the censor, and the image has some extra image in the margins. Then have the camera track your shakey projection, and then use magic or software or something to knit together a nice crisp image.

• 2. Track some points on the image, and move the lens around a bit so that any given point on the censor always sees the same bit of the image, or move the censor to achieve the same thing.

• 3. Use gyroscopes mounted on at least two axes to resist the movement of the entire camera. Things spinning around like to keep doing it. If you take the tire off your bike (stop first) and hold the axle while someone else spins it as fast as they can, it becomes difficult to change the angle its on. This is why a spinning top (do they still have those?) stays upright, and is simply due to the universe being an amazing place.

Amazing!

The camera shows its age through its 8 megapixelness, as at the time of writing, thats about 16 megapixels short of where it should be.

I bought it from a second hand camera store in Japan for $150 with the Canon 18-55mm zoom, and I got the second lens, a Tamron 100-300 zoom, for $10 from the bargain bin.

Thanks Tom.

Toms a friend of mine.

Hes really good at buying way too much camera gear from junk bins. His hobby includes buying those instamatic film cameras that were big in the 70s. He likes to buy them when they have rolls of film still in them so he can process the film. In some subtle way, thats slightly different from buying some old photos.

Which is nice.

For him.

Hes kind of a time traveller, but he only gets to look, and doesnt get to choose what he looks at.

Mostly he gets to look at darkness.

Sometimes darkness, but with slightly mouldy edges.

Luckily, I dont suffer from collecting things other than my collection of odd people I know.

Toms one of my favourites.

Thanks Tom.




120 Things in 20 years - One of the best parts about getting my new, second hand Canon 20D camera, was getting to look at the Japanese supermarket junkmail it was packed in. Its been 20 years since I was in Japan, and the junkmail paper is now of even better quality.

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Lights Camera Basil!

The Aquaponic Garden with Grow Lights (20,000 Lumens)

The lights have arrived!

Ive got the system set up now so the lights are on a timer, and the pump plugs into the light, so it will come on when the lights come on.

The water is crazy clear right now. Its so fun to watch the fish darting around! Plants move and grow too, but theyre not as exciting to watch. Ill be interested to see how much they grow with the lights!

The only two herbs they had at the grocery store were basil and mint. I bought a basil and transplanted four of the plantlings into my growbed. The rest will go up to the kitchen for now.

I didnt buy the mint, because mint is crazy. I might set up a "windowfarm" next to the aquaponics units and risk mint in those. Mint is very aggressive and develops roots like theres no tomorrow.

I think if the world were struck by some disaster that wiped out almost all plant life, mint would be amongst the plants that survived. However, no need to give mint a place in my garden.

In other news, I havent heard from the Virginia Department of Game and Inland Fisheries. Theyre the folks who need to inspect my setup prior to me getting a license and purchasing tilapia.

Im tentatively planning to go with 25 male fingerlings from TilapiaFingerlings.com. That way I shouldnt have to start off dealing with the issues of breeding females, fingers crossed! 25 male fingerings will run me $102, which includes shipping.

My approximate costs to date have been:

$150 for tank and grow bed
$141 for the grow lights
$12 for gravel
$30 for the air pump
$45 for the water pump
$20 for the plumbing
$80 for the shelving unit
$15 for incidentals (e.g., metal tape, 2x4 sheets of thin luaun plywood)
$30 for vermiculite, seeds, and plants
$22 for licenses
$30 for water testing kit

So my total outlay has been $575. Add fish ($102) and food ($20) and were just under $700. With care, you might be able to knock the price down even lower than that.

If you didnt have a drill, bits (1/4", 1/2", & 1"), a door knob hole saw, and a saw, youd have to purchase (or borrow) these. Ive got a timer and am decorating to hide the industrial black plastic, but those arent necessary expenses.

Color me happy!

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Aquaponics Cucumber

Cucumber.

Strange word.

Anyway, Ive been getting good results with hand pollination. For some reason the female flowers (the ones with the fruit attached to the back of them, open well, but the males dont.

I thought bees were supposed to do this work. There are no bees anywhere doing anything. Is there a strike or something. Perhaps people are talking about it on TV. Maybe there is a reason to watch TV after all.

I planted my four cucumber plants in the corner of the growbed nearest the door. The door stays open for summer, so I trained the plants to grow outside.

Actually it doesnt really matter if the door was open or closed, they could be made to grow under the door with a little pruning.






Ive been using a small, soft artists paint brush to tickle all the flowers on my plants and do the bees work for them.

Every female flower Ive hand pollinated has produced a very tasty fruit, but none of those that I left for the bees have manage to set fruit.

There seems to be a lot of fruit. More than we could use, but they are finding good homes with friends and relatives.

One even went to a friendly relative.





120 Things in 20 years - Cucumber is still a funny word.

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Electronics Aquaponics Demand feeder hits

It turns out the fish have been hitting the lever, but the switch hasnt been working.

It should be an easy fix, but for the time being, this will have to do.

[edit from the future - I fixed the switch and got a few proper hits with feed delivered within a few hours]

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Thinking Bacon

I thought it was just me that was a big bacon fan, but lately Ive been seeing bacon T-shirts, bacon poems, bacon coffee mugs etc everywhere I go online. Which brings me to remind myself how the net works. If I do a search on google, I see things that google thinks Im interested in. That means that if there is even the slightest connection to bacon, I get a lot of bacon hits. Everything I search for adds to the database of things Im interested in, so google thinks that even a tenuous connection is worth reporting, because Im clearly interested in bacon AND electronics.


If I do the same search on someone elses computer, I get different results.

One of the side effects of getting good search results that are relevant to the searcher, is that there is no editor to decide on the things that everyone is interested in. That tends to mean we keep a tight lid on broadening our horizons. One role of a TV news editor was to decide that say, an impending asteroid impact about to wipe us all out, was important to even people who were only normally interested in puppies and real estate. This, because it might impact their desire to buy more puppies or real estate, or might just be worth knowing about in spite of their desire to buy more puppies and real estate.

Google never includes impending asteroid impacts in search results for "haberdashery" on your grand parents computer.

A good haberdashery magazine editor might at least mention in passing thats its worth buying some extra buttons to see you through the coming asteroid induced ice age.

Im guessing magazines are a weigh point on that path, from hearing about things to only hearing about our obsessions.

The net can be an amazing way of gaining information, but it can also be a trap, set to turn us back on ourselves, and blindly confirm that which we already believe to be unconditionally true.






120 Things in 20 years is just reminding itself to wake up and smell the bacon.

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Electronics Infinite battery life camera

Ive had to make a few compromises with version 2.0 of the demand feeder.

One is that Ive re-written the code and made it a lot more simple than it was originally. Ive still got the old code, and Ill use it and post it when I make it a little better, but the full version resets each day at dawn as one of the overfeeding protection measures. I only have two silver perch in a 100L fish tank, with 300L of filtration media, so they can have as much feed as they like. To encourage the pressing of the button, Ive made it so that they only get a small amount of feed each time, but they have the opportunity of more feed after only eight minutes since the last feed. The point of making a simpler version of the software was so that it would keep a running total of all events like the number of times the fish have hit the feed lever when the light is lit, and the number of times when the light isnt lit.

The fish pressed the lever only once in the 24 hours since I added it to the system. This may have just been a tail swipe, but it would have delivered feed, so some reinforcement of the behaviour of getting at least near the lever has begun!

It wont take them long to get the hang of it.

I ran the camera until the batteries were dead last night, but the hit must have happened some time since dawn while the camera was on charge. To solve this two hour filming limit, I created this.

Its a camera taped to its battery charger, that is in turn taped to a tripod.

I plugged it into the earth leakage safety switch that the rest of the system is plugged into.



It blends in a bit with the actual feeder, but thats the feeder with the birds nest of wires sticking out of the back of it. The orange looking light under the camera is the LED that tells the fish feed is currently available. The red light at the top is the power on LED, and the yellow one is flashing out the number of feeds allowed in a day (even though the thing no longer resets after a day, so really it shows the number of feeds allowed ever). There are also LEDs that flash out the number of feeds so far, the feeds remaining, the number of attempts made at the lever when food isnt available. That is when the feed LED isnt lit, because they just fed recently. And one more that flashes out the size of each feed thats delivered. The size is measured by how long the motor is on for, and doesnt actually represent the amount of feed, but on average, should spill a predictable amount each time. Currently, they would get around 5-8, 3mm pellets each time they hit the lever.

Hopefully, Ill have some video soon.



120 Things in 20 years - Electronics - Infinite battery life camera - This project is far from finished.

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Stirling Engines My second attempt

I think I may have actually built something.

Or nearly built something.

It looks like this and almost works.

Most of that junk in the picture isnt part of it. The bits that are part of it are the bits that look like a Stirling engine.

Sometimes Stirling engines look like tin cans, and wire, and pink balloons. They also look like cardboard disks with blu-tac stuck weights all over the place to act as a flywheel.



I planned on posting a video of it working today, but it doesnt.

What it does do is spin around freely for a few seconds when you spin the flywheel. It also has a displacer and power piston that are configured in such a way as to do what they are meant to.

I think.

When I put it on the stove top, it nearly feels a bit like its trying to work, then smoke starts pouring out of the seals, so I take it off the heat before it catches fire.

Who knew tape might burn.

Yes. Thats right. I thought Id make my engine using gaffer tape for the seals.

It doesnt work so well.

Tomorrow, Ill buy some glue. I seem to remember hearing of someone who used two part epoxy on a real engine crankcase, so it should cope with the heat.

Maybe.

My next choice will be solder. Solder melts when you get it hot, so Im guessing that wont work so well either.

But the glue might.

If it works, Ill put up a big build post. If it doesnt Ill try something different.




120 Things in 20 years - Using a random evolutionary approach to building a Stirling engine. Chuck some bits in a bag, shake, then cull anything that doesnt work like a Stirling engine. Ill get there eventually.


[edit from the future - For anyone concerned that time may not be linear any more, this post was actually written two days ago, but for some reason didnt get posted. As a result the post after this one was actually two days after this one.]

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