Hello,

I am a college student attempting to follow the plans detailed on the following blog (http://120thingsin20years.blogspot.com/2012/12/electronics-aquaponics-demand-feeder.html).

It would be greatly appreciated if someone could give me an idea of how much the supplies to build the schematic would cost (right now I do not even have PICAXE) and where to get them.

Thank you very much!

 

Hi.

You can buy most of the parts here: http://www.picaxe.com/

 

Welcome to AAC.

What country are you in? This will help us tailor our suggestions to help you save on shipping.

Is there more information on the schematic elsewhere? I can't read most of the text on the schematic.

Do you have a motor selected? If so, what is the running current? This allows us to properly size the MOSFET.

We're happy to help you out if you could describe in detail what it is you'd like to do. Sorry, I'm having a hard time figuring out the purpose of the schematic from the link you provided. The post appears like a page from the middle of book with no easy way to navigate the book.

 

What little I can read on the schematic makes me a little concerned. For example, the download circuit for the PICAXE has the wrong value for R2. It shows a 1k, but it should be 22k.

In glancing over the blog, I don't see where the blogger has actually built this. Did I overlook that part? If not, that would add to my concern.

 

What are we feeding?

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.

 

What are we feeding?

I'm not sure of the links policy here as this is my first post. Sorry if I have broken any rules, but I link in the interest only of providing more info.

This fish feeder was my first electronics project, so there were a lot of errors along the way. Much of the stuff in the threads on my blog, and on the backyardaquaponics forum contained errors. because I was learning as I was publishing. That's kind of what I do.

I cant remember what Tigger (this threads originator) was feeding, but my original design was to feed my Australian native fish - Silver Perch, as a plate fish (ie for me to eat) . Tigger contacted me to get help with the project and we eventually sorted out some stuff that might mean something to other people. I had the device working with the fish feeding for quite some time, but didn't document it very well. You can see Tigger's final hand draw schematic here ...

http://www.backyardaquaponics.com/f...t=14584&hilit=demand+feeder&start=555#p453730

and some video of my original picaxe feeder working here ...

The fish that hit the feed lever in that video is now over 40cm, and the only one that didn't get eaten. It's now kept as the reserve nutrient supply over winter to keep a few winter plants alive, and will probably never make it to the plate.

All the others were delicious.

Also... someone made a really good auger (personally I used an old wood drill bit from a hand cranked drill) out of twisted, heated, PVC as part of an instructable derived from my feeder. I don't think it had the electronics to limit feed, but I might be wrong. It mentions a "timer" but I'm not sure what they means. You can see their very clever auger here http://www.instructables.com/id/DIY-automatic-fish-feeder-for-aquaponics/

My original design had...

1. A light that came on to tell the fish that food was available (it took only a few false hits for the fish to realise they wouldn't get fed if the light wasn't on)
2. PICAXE restricted total amount of feed in any given 12 hours (in auger seconds)
3. PICAXE controled delay between feeds ( to allow the growbeds to process the nutrient in case the fish decided they wanted all their days feed at dawn or something
4. PICAXE reported (blinking LEDs long for 10s short for 1s... number of feeds so far today, number of illegal hits (when the light wasnt on)
5. some other stuff I cant remember
6. POTs to set each of those values, and LEDs to flash out the new values as they changed
7. a light dependant thinggy to reset the entire kit at dawn every day so the fish could feed based on a natural clock to reset their feed limit rather than some human thing based in Greenwich. (never got this bit working)

 

Hello,

I am a college student attempting to follow the plans detailed on the following blog (http://120thingsin20years.blogspot.com/2012/12/electronics-aquaponics-demand-feeder.html).

It would be greatly appreciated if someone could give me an idea of how much the supplies to build the schematic would cost (right now I do not even have PICAXE) and where to get them.

Thank you very much!