Thinking - Three

I was hanging out with a three year old, and a pair of hand held UHF radios the other day.

I said, "You have to push the button and hold it down when you talk.".

She pressed the button briefly, then lowered the radio almost to the ground before she spoke.

Kids are smarter than grownups.

Electronics - Reasonable success milestone

What's pink and white, and looks a bit like a short alien under stage lighting, talking to a tall man with a diode for an upper leg, and a friend with a paper bag over his head?


Too much Christmas spirit.

120 Things in 20 years - Electronics - Demand feeder diorama 

120 Things in 20 years - As at 2012 12 24 23:56 my demand feeder actually works (if you include a light where a motor should be as "working" (which I do)). I declare this point in time , an Official reasonable electronics success milestone.

Electronics - Aquaponics - Motor woes

I found out what was wrong with my motor.

I'll start that again.

I've been having trouble with my motor.

I opened it up and found what the problem is.

Too many parts inside just rattling around doing nothing.

I'm trying to explain to them that everyone has to pull their weight, otherwise nothing gets done.

So far they are ignoring me.

It's hard to fix something when you have no idea what it looked like before it was broken. Firstly, the bit of metal on the end of the yellow wire has to fit through a hole that's half the size of the bit of metal. But it did just fall out through that hole.

Clearly someone's being funny.

There are two bent bits or copper that look like they make contact with the shaft, but I cant see how they could without wearing out, But then, they are actually worn, or at least they look worn. but if there are magnets on the outside that don't have power going to them, and a rotating shaft with copper coils that gets it's power through these copper bits, why not just build the thing inside out, with the coils on the outside, stationary bit, and the fixed magnets on the inside. That way you would avoid the need to put power through a rotating shaft.

I must be missing something 

120 Things in 20 years - Electronic and Aquaponic motor woes, and much of the world, are confusing.

Electronics - Aquaponics - Demand feeder 2 breadboard

I've started work on the electronics and programming of my new demand feeder.

I also found my cardboard fish from the first version demo on youtube, so I thought I'd re-make the video with the new chip and this time, a counter that flashes the number of illegal attempts to get food. There will be another counter to flash feeds and a few others.

But for now, here is where I'm at so far....

I'm feeling a lot more confident this time with a little better understanding of the electronics involved.

120 Things in 20 years - I'd better get back to my Electronics - Aquaponics - Demand feeder 2 breadboard

Electronics - Aquaponics - Demand feeder version 2 schematic

I've been busy.

I've been busy learning how to create a plan, and a circuit schematic to go with the plan.

It looks like this, and I think it might be finished.

I now know a stack of stuff that I didn't before.

Things like...

It's ok to not connect up the earth (0 volt) wires in a schematic.

You just label them as earths, and leave them hanging in the wind.

It actually makes the diagram a look a lot better to read. (thanks SuperVeg)

When you make a real version, all those earths, are connected to the power supply's negative terminal.

So now that I have a plan and a circuit diagram, my next step will be to build a working model on a breadboard, then solder the real thing together.

I've already started.

I've also started to write some of the required software.

120 Things in 20 years - It's 3am

Thinking - Electronics - Education

I'd like to take this self created opportunity, to comment on my experience of the South Australian education system.

It was really, really boring.

For example, the following two phenomena would have got me very interested in science, but were conspicuously absent.

Did you know that if you stick a powerful magnet on a battery, then reach a copper wire so that it balances on a point at the top, and just slightly touches the magnet on the bottom, the device creates a stack of rotational motion?

I didn't, and I've been to school.

It looks like this...

And if you add that failure to educate me to this other example, you see why I'm a little disappointed...

In this second video, the rare earth magnet creates a magnetic field in the copper pipe, and that reacts with the magnet using ordinary magic.

 Both videos are real, but totally lacking in my childhood experience. 

Not happy.

120 Things in 20 years - When thinking about electronics, and education, I want my money back. 

Electronics - Aquaponics - Aquaponics manager

I'm trying again.

I'm making a digital demand feeder, and I have a few other ideas I'd like to try as well.

I'm using a PICAXE 20M2 chip, And I've managed to get as far as this...

Clicking on the image should make it larger.

If anyone is willing, can you please check my layout to make sure I limit how many chips I toast before I actually start toasting them.

This is the serial data connection from the stereo plug to the chip.

The overlay is what it should look like, the rest is my interpretation.

For people that don't know this stuff, the serial data connection is the bit that makes it possible for me to send information from my computer to the chip.

I write code  (computer programming stuff) on my computer on some software provided free by the PICAXE company. When I'm happy with my code I send it to the computer chip (the grey thing that's centre right with all the legs) via a cable that has a USB plug on one end, and a stereo headphone jack on the other. The headphone jack plugs into my project, and the USB end plugs into my computer.

Once you connect the power supply, the chip starts running it's program, and that program typically loops around forever, waiting for external inputs from things like switches, variations in connected voltages, or fish bumping levers.

When the chip detects inputs, it can react according to the code you have written, and produce outputs. (like when your computer displays a box with buttons marked "OK" and "Cancel" , That box is an output, if you click one of the buttons, that becomes an input.

So the code might look something like this...

read this line over and over, unless the fish pushes the lever,  then run the rest of the code

       power up the feeder motor for 3 seconds

       count to a few billion to wait a while so the fish dont get too much feed

go back to the first line

That's roughly what code looks like, but unfortunately computers don't understand English very well, so you have to use very structured language, and code words to make it all work. I wont go into that here.

Here's another bit that connects the lever that the fish will push when they want food...

This time the overlay shows the circuit diagram of a switch and it's connection to the chip.

I'll use a momentary contact switch that is only on when there is pressure on the switch, and reverts to it's natural state - off, when there is no pressure on the switch.

I'll attach a lever that extends down into the fish tank so the fish can press it.

When the fish press the lever they send an input to the chip that sets the code in motion. The code does some calculations and checks to make sure the fish aren't being too greedy, and if all is well, the chip turns the motor on for a few seconds.

The motor section looks like this (I think)...

One form of the chips input and output abilities, is to set the pins "high" or "low". That being high voltage (up to 5 volts) and low voltage down to not very much.

The chip can also receive high and low voltages as inputs.

So we design the circuit so that flipping the switch changes the input from either high to low, or low to high, and then write code that uses the different state to start some other bit of code. The other bit of code might change a different pin from low to high, and trigger the motor.

That code might look something like this...

keep looping this line until the pin the switch is connected to changes from low to high, then...

       check that the fish haven't had too many feeds so far today      

        if they have had too many feeds go back to the first line, otherwise keep going to the next line

       set the pin to which the motor is connected to high, to send power to the motor.

       add one to the number of feeds so far today

Go back to the start

The computer you are sitting at is essentially just a really, really, really complicated version of that.

The chip I'm using works faster than my first desktop computer, and only costs a few dollars.

Please give some feedback on the design if you are familiar with this electronics caper, as I'm still a bit vague on all this stuff. My greatest problems are around interpreting a circuit diagram onto the breadboard with special regard to shared nodes, where say in that last picture all three components meet at that one point. When I place components on the board, they rarely fall in the same layout due to space restrictions etc. Even the fact that the strip board often creates the need for zig zags rather than straight lines. ie three components in a straight line might need to be stepped with each component and wire on a different horizontal line. This can really mess with my head at times. Another problem I have is with missing track cuts that cause shorts.

I also have many other problems with stuff.

I'm not sure I believe in electricity.

So please help me through this part if you can.  There's a comments section under this post, or you can get involved here at Backyard Aquaponics. The project is all open source, and the details of the code, the electronics, and the PVC construction will all be freely available on this blog and at that link.

120 Things in 20 years re-bites off more than it can chew with  an electronic, aquaponics manager.

Photography - Time lapse camera

Someone nice gave me a new camera today.

Thanks someone nice.

It does time lapse photography.

You set it to take a shot every 30 seconds or whatever (30 seconds to 990 minutes), and when you feel like it, you turn it off pull out the memory card, and knit them all together with some software * so you have a movie.

It looks like this.

I've played around with it a bit, and so far the results are excellent.

It was given to me, so I have no idea how much it cost, but they tend to be called "garden cams". A search for "garden cam" will see you on the right track.

With a name like that, clearly they want me to film some aquaponics growth.

Mine is made in china and the box is labelled "Live Cam".  If you do a search for "Live Cam", you get a list of every porn site in the world.

I cant endorse it, or any of the garden cam things mentioned, because I dont know how much mine cost, I haven't used any others, and I never said I would, but I'm pretty stoked at having one to play with. From the size of the jpg's it makes, It's around a three mega pixel camera, so it should make for a reasonably decent film. It's not going to be Imax or anything, but it should be a few million times better than your average liquor store hold up security camera footage.

I suspect it will end up pointing aft, mounted on the back of my little boat for the duration of my planned, epic Murray River adventure.

I've really got to get to work on that boat.

Anyway, this version has a micro SD card slot which means it can hold up to 32 gig of pictures. I just worked out how many 4 meg photo's that is, but I closed the calculator without looking at the result, and I never go back.


You'll have to work that out for yourselves.

It should hold a day's worth, and hopefully the batteries will also last a day at least. I suspect the camera goes into a sleep mode (otherwise the 990 minute setting would be a little pointless) where it doesn't draw a lot of power, but I'll be taking my trusty laptop (that was ripped from the jaws of landfill, and must be 20 years old), so charging (via USB) and emptying the memory shouldn't be an issue. Although, come to think of it, I think the new camera has more memory than the old laptop.

I'll work something out.

On a side note, and interestingly, you can drag a photo of a product into a web page showing google images, and it will search the net for images that match. I recently used it to find all the different labels that my new tent is manufactured under to see how much I got ripped off. (turns out I didn't)

But generally speaking it's a good thing to do before you buy rather than after to see if you got ripped off.

So, if you want to buy a toaster that burns tomorrows weather forecast into your toast, the same device might be marketed under three different labels, at three different price points. The exact same device, made in the same factory, not some kind of poorer quality knockoff.

It's a crazy, crazy world in which we live.

So get the photo, and save it to your desktop, then open google search, then click "images". ie go to google image search. Now grab your pic from the desktop, or another browser tab (you don't have to save it to your desktop (in chrome at least), and drag it into google image search.

It will find all the other versions and brands of your product that are using the same, or similar promotional pics.

Try it with the next product you buy, and depending on where you shop, you may be pleasantly surprised, or utterly disgusted with the universe at large.

You can also try it with a person's image, but it might make you sad. Most peoples's secret lives are very, very, boring.

Stupid universe.

*I use OpenShot Video Editor - a free, open-source video editor for Linux licensed under the GPL version 3.0

120 Things in 20 years - Photography - Time lapse camera. We humans are just like ants, but with no sense of humour.

The beer traps killed quite a few slugs, but it's clear many of the new hatch-lings found my sprouts before they found the traps. I guess that's the problem when they are hatching in the middle of the growbed.

All but three were taken off had their leaves chewed off, leaving just a stem.

I dont like slugs much at the moment.

So now I'm forced to go back to raising seeds in something a bit more like dirt.

This stuff comes in thin, hard, disks.

I think it's peat.

You put them into a tray, and pour some warm water on them.

They look like this when they are half expanded.

They must be poured into a bag, and then compressed, because the bag seems to unfold as the fibre expands.

The bag is thin like rice paper.

It might be rice paper.

I dropped two Sweet Remano pepper seeds into each one.

At first I thought I'd thin each pot out to one seedling by choosing the stronger ones, but now I think I'll just leave them if both grow.

I love this variety so much, that I'm going to grow as many as I can.

I should be able to crowd them in a bit as they have fairly sparse foliage, so ventilation and mould etc shouldn't be a problem.

The grow media looks like this when they are full expanded.

The device has a lid.

It was given to me by my sister in (common) law.

Even if this works well, I'm going to miss out on a lot of capsicums. One of the two plants I have that stayed alive from last summer already have full size* green fruit. That's the variety I dont like so much. The second of the two plants is my favourite sweet remano variety. It doesn't yet have fruit, but has the beginnings of a few flowers.

*for the miniature variety that it is

120 Things in 20 years - Thinks watching peat expand in rice paper bags is... Slightly interesting.

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