Electronics - Aquaponics - Demand feeder hits

It turns out the fish have been hitting the lever, but the switch hasn't 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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Electronics - Infinite battery life camera

I've had to make a few compromises with version 2.0 of the demand feeder.

One is that I've re-written the code and made it a lot more simple than it was originally. I've still got the old code, and I'll 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, I've 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 isn't 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.

It's a camera taped to it's 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 that's 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 LED's that flash out the number of feeds so far, the feeds remaining, the number of attempts made at the lever when food isn't 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 that's 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, I'll have some video soon.



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

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Aquaponics - Silver Perch update

I recently ran out of fish feed, so I've been hand feeding them worms, and what ever they call fly larvae in whatever part of the world you live.  They are called "gents" here when bought as bait, or stored in a fridge shared with people who don't want maggots in their fridge. "Maggots" when found in smelly stuff.

The point is, as a result of feeding them live food like worms, gents, and caterpillars, they are venturing a bit further up the water column to the point where they are now easy to photograph.

This guy is pretty big.

And heavy looking.

It looks like this up close.

I have no idea how big or how heavy it is, but I'll try to get a photo next to a ruler.

I wont try to weigh it because I cant think of a way to do it without stressing it.

I'll weigh it if I ever eat it.



120 Things in 20 years - Sometimes your aquaponics silver perch get quite big when you're not looking.

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Electronics - Zero K breadboard resistor

I always try to not just "take" when it comes to learning a new thing, but this electronics caper has really been worked out already by a whole stack of really clever people.

I cant seem to come up with anything to offer the world, so I came up with this as a forlorn attempt to quench my karmic debt.

It's the zero K breadboard resistor.

It's a wire with a knot in it.

It works just like a wire, but is easier to handle.

It's all I've got at this stage.





My karmic overdraft doesn't seem to have changed.






120 Things in 20 years says, "When thinking electronics, a zero K breadboard resistor can be simultaneously just right, and not quite enough.".

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Electronics - Motor repair success

I fixed my broken motor that is meant to power the auger via the tiny gearbox that will deliver the fish food in my demand fish feeder.

Normally I prefer less complicated sentences.

But I'm all excited.

It turns out, the problem was there were simply too many parts.

Or more accurately one too many parts, and one that was simply in the way.

The silver bit was the one too many. I think that broke off the bit where the wires connect, and fell into the motor, generally clagging things up.





The little nylon washer creates part of the front bearing, but it made getting the brushes back on impossible, because it had to be put on after the brushes. That's an impossible path through the plastic front. I don't have the kinds of quantum tools that walking through walls requires. And if I did, I wouldn't waste my time with motor repairs. I'd do much more interesting stuff, like poking my head through the fridge to see if the light really does go off when the door is closed.

So be leaving out those two small parts, I managed to make my motor work.

Only two parts.

And they were tiny.

Those that know me will realise that's a pretty low number of excess bits after a repair. I think I did quite well.

So well in fact, that it looks like this when it's running.

That should do nicely.

What this all means, is that there is really no reason why I cant put this thing together today, and actually finish something.

Maybe.








120 Things in 20 years - If I keep repairing them, one day an electronic motor repair might leave me with enough parts to eventually build another motor. I should fix cars.

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Electronics - Aquaponics - Demand fish feeder software

As far as I know, the software is all working on my demand fish feeder.

It's a bit of a mess, with a few goto statements and a few unused variables. I'll fix it in time, but for now I'm going to move onto getting a finished product up and running. As far as I can tell with the software simulator everything works, but the real world might be a completely different story. (the breadboard version also works)








A switch lever extends down into the water. If a light near the lever is lit, the fish can press the lever and feed is delivered. Feed can also be offered with an override button that sets the light on and the feed on if the fish hit the lever (so you can show people how it works)

Dawn detection seems to work. In the end I went with two startup options.

1. A human who holds down the FeedNow override button during startup, then taps out the approximate number of hours since dawn. This skips the code that searches for a new dawn.

2. An abnormal restart with no human. This stops all feeding (there might have been a blackout, and subsequent ammonia buildup) (note to self - add code that flashes some lights to indicate the device is in abnormal start mode so a human can reboot it if they desire). Feeding resumes after night time is detected, and a dawn is detected.

The user can select (via a screwdriver to resist little finger making their own adjustments) ...

 - the feed amount per day in tenths of a second of motor on - from 0 to 65 (I'm guessing I'll use 1/2 a second per feed event) The motor turns an auger under a hopper full of feed. So there is another adjustment available

- The number of feeds in a day that are offered (0 - 255 per day)

- The level of light at which dawn is detected. This allows for a system built in the glow of a streetlight or whatever. At dawn each day, all the numbers reset. This is a bit of a problem as far as reading how many feeds were delivered in a day, but for now I'll leave it as it is. My fish feed like crazy at dawn, so I want to give them the greatest opportunity to feed. Eventually I'll add a data logger, so it wont matter when it resets.


The system reports...

- the number of hours since dawn

- the number of feeds since dawn

- The number of false hits to the feed lever when the FeedIsAvailableLED is NOT lit (these will go down to near zero once the fish learn they can only get food when the light is on)


I ran out of feed a while back, and have been feeding my two big silvers on duckweed, lettuce, and worms, so I will need some pellet food before I can test it in the real world. (I still have the PVC device from the first version).

I'll also need a motor as my original one is no longer with us.

The feeding regimen isn't very intelligent at the moment, but I'll do a bit of research, and add some code that tries to deliver the maximum amount of feed in a day that the system can handle. This will probably involve allowing 3/4 of the feed to be dumped at will, with the rest being spaced out over the day ... or something. I haven't given it enough thought because I don't really know what the fish need. My experience in fishing for wild fish indicates that the feeding pattern is far from a constant grazing all day long. I'll work it out.

But...

It's going to work. In fact, it already does.


120 Things in 20 years That's all. Just 120 Things in 20 years.

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Aquaponics - External Tomato growing in fishtank

I've been away for a few days.

It was nice.

One of the best things about aquaponics, is the fact that it takes care of itself. I came home to a system overflowing with produce, and with lettuce that was ready to eat, where when I left, it was nowhere near ready. It's amazing what a few days can do.

Also, not seeing my system for a few days made me realise just how big my tomatoes were getting.

That's them hanging off the side of the little grow house.

I'm calling this experiment a complete success. I had to tie the foliage to the growhouse to support it, because it was starting to pull the roots out of the water.



There's fruit forming everywhere, and in spite of the late start due to pruning it all back to only a few leaves, I think it will be a good season. Once the capsicum season is over, I think I might just pick up the tomato, and move it back inside for winter.

The tomato grows through a PVC pipe to stop it growing inside the growhouse, and the roots are all just hanging inside the fish tank. There is no media involved, and it relies on the water being oxygenated by the water movement, and the nutrient it gains from the fish.

This has been a lack luster post.

I'm sleepy from too much driving.

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