Backyard Aquaponics
A place to discuss aquaponics

After recently loosing 200 SP because I bumped the pump lead a little and didn't notice I feel very inspired to get some monitoring happening fast. I was intending to go raspi but given the maturity of this project and Chium, anfu strong knowledge I'm compelled to run with this project. It will take a few weeks to get the parts in, I already have some but not all. By my calculations building this project from scratch will cost around AUD$520, with almost half that cost coming from the Atlas DO kit.

Chiumanfu, my experience with Ardunio is limited so excuse the questions if they seem obvious and sorry for the quantity of questions, but I'd like to know;

- If I leave off the Atlas DO, can this be easily disabled in the code. (in my experience DO monitoring has never been necessary if my water pumps are working)

- How hard will it be for me to customise the code, after the fundamentals are stable I'd like to:
| _ Create rules for flood and drain. I don't use a bell syphon but instead flood and drain, ideally this would be sensor triggered, eg. pump off until bed is drained, although in hot weather I would trigger when the bed is only half drained.
| _ I want to control greenhouse curtains automatically, inspired by: https://www.youtube.com/watch?v=qmSyfodR7E8
| _ Automatically dose up/down pH in the system: eg. https://www.youtube.com/watch?v=bbRGrWuBp-Y
| _ Manual override (although alerts should still trigger of course) pump state.
| _ Have two pump inline and auto-switch on pump #1 failure.
| _ Switch air pump on when water pump fails

Also, if I customise heavily will this make it difficult to include or port your upgrades back into my code?

Lastly more as a side note, how come you chose the keypad method over a touch screen which seem quite nice, eg. https://www.youtube.com/watch?v=nq5Wde_V-TE

Many thanks
Brendan

Disabling any sensor is pretty easy if you know what to look for. There are four sections that each sensor appears. It has a variable declaration at the top, a routine which is clearly labelled and it appears in the grovestreams upload section. It may or may not appear in the control section depending on what sensor it is.

I can help you comment out any sensor, just let me know which ones you want to cut out. I can also help you add sensors if you need more temp sensors for instance. Better to take these conversations offline, so send me a PM with your exact system layout and requirements.

I know the Dissolved Oxygen sensor is the biggest pill to swallow in this whole thing, accounting for over half the total cost. But really it is the most critical. I think most fish deaths are in some way attributed to low oxygen levels, more so than pH or any other water parameter.

This is easy to do in code. The problem is what sensor are you going to use? How can you tell if a growbed that is full of media is half drained. Maybe a small float switch halfway down a standpipe with holes drilled all through it? What if the float switch sticks?...

Super simple. Tie the motor to a relay and control using the greenhouse temp/humidity exactly the same way that I turn on the fans when the temp/humidity gets too high.

This can be as simple as adding a big red panick button which toggles the pump control relay. Not sure exactly how you want this to behave.

This is a really good idea and I just might integrate it into my system. Thanks for the idea.

I have my air pump running all the time on battery backup. I think it is important to have a certain level of redundancy. Arduino's are not bullet proof and can lock up for various reasons. It's a good idea to have something providing oxygen that is independent of the controller.

There is an even better one here with fancy iPhone inspired graphics and such. The problem with elaborate GUIs is the amount of memory they take up and the time it takes to render. You see the lag as the screen is being drawn? During that time, the arduino can not do anything else. It may not seem like much, but this is an eternity for a microprocessor. There is already a lot of time sensitive operations in the sketch that require blocking code and adding a touch sensor scan and display refresh to the loop would slow things to a crawl.

You should be able to make a simple water level tester with two wires at the depth you want, stuck to opposite sides (inside) of a thin PVC tube. Then measure conductivity. A few different lengths of wire will give you accurate depth readings if you need it.

I haven't tried it, but a glass of water and a multimeter should test it.

The conductivity method would technically work but only if the probes are stainless or titanium. Copper will change resistance as it corrodes and also leach into the water.

If your water is super clean and the TDS is low, you may not see any conductivity change at all.

For one reason or another, the aquarium guys consider this method of water level sensing not reliable.

You could try out eTape, though it is relatively new to the market.
http://www.adafruit.com/product/464

Thanks for taking the time to answer Chiumanfu and for been an all round swell guy and been open to discussion




I agree on it been up there with the primary fish death reasons. I guess my thinking was that I know with certainty that as long my water pumps are working then there is no D.O. problems, so why use the electricity when its not needed. I've run 80 mature trout and 200 half-sized SP with no issues and this is still using the flood and drain method, so my pump is generally on 45m / off 30m. Your comment on the ardunio freezing is valid and sobering though and I'm now leaning toward your thinking. If your pumps are under ardunio control then it would be sensible to run a simple external script check/alert to cover the down/frozen ardunio scenario but however many levels of redundancy is sane. I guess the ideal would be that the air-pump backup trigger is not reliant on the ardunio however that now gets into silly territory I think.



I'll think it through, the other approach would be to just go timed, ie. switch pumps off then wait x mins. Fine tune x as required.


Anything with a big red panic button certainly has my vote! Again I'll think it through carefully, where-ever possible I'd love to contribute back changes to your code.



I understand now, if only there was something small and yet built with a dedicated GPU
Silliness aside I understand the reason now, how easy / resource hungry is building a neat GUI via http?

Actually, if you're considering the GUI/http route, then you may want to start looking at a Raspberry Pi for the front end. Possibly still use the Arduino for control, and have the Pi and Arduino communicate over I2C?

I was been a little cheeky and making an not too subtle reference to the raspi

No problem. I like being able to contribute back to this group. I've learned so much from this forum.

That is surprising that you can have 80 mature trout, no water movement for 30 mins in the heat of an OZ summer and not have DO drop critically low. Your water volume must be large. There are ways to make the Arduino more reliable. Watchdog timers for example. The watchdog timer is a little buggy in my MEGA board so I haven't tried implementing it. When you buy cheap chinese clones, they almost always have out of date bootloaders.

Timed is a valid method as long as you have an overflow pipe.

When you get into fancy GUIs or HTTP interfaces, the RPi is 100% the way to go. The Arduino is not the right tool for those jobs. I feel like the Arduino is a better choice for this application because it is more stable in long term operation in less than ideal environments. All that GUI stuff just adds complexity and complexity usually reduces stability.

Me again.

I've just finished buying most the parts on the list you provided, should arrive in 10 days or so from China. Could you please describe the elements I'll need not on the list also please to make it easier to find them on ebay. Things like types of ribbon cable, connectors, prototype board you used for cleaner connections, M3? stand-offs, various terminators, pins etc. I realise this is probably just odds and ends that people have laying around who work with these things often. But for those like myself who do know there way around a soldering iron but aren't familiar with the terminology of the parts it would be very helpful.

I have a decommissioned electrical box I intend to use for the encloser complete with DIN rails, mounted power supplies, DIN relays etc, its a bit over the top size wise but hopefully will make for a tidy result. I'm not sure what parts I can use, should be fun to find out.

That is a tough question. You can build it up as complex or simple as you like. Most of the required hardware will be determined by the case you choose.

I suggest using IDC ribbon cables to connect the LCD and Relay board.
C14 socket to plug the power into.
AC bulkhead sockets to connect your devices to the relay board
Dupont wire M-M connectors to connect all the Arduino headers to other components.
Screws, standoffs and nuts to mount everything. If your box has DIN rails, you can use DIN mounts for everything.
Heatshrink to protect the AC side.
Adhesive back cable tie mounts to keep the cables in order

Thanks that's very helpful. Another thought, you make mention of "magic" washable solder flux. I found this on ebay http://www.ebay.com.au/itm/261802062085 is this it or is there a better supply?

That is just the solder. To make a really clean joint, you should use liquid flux and apply a drop with a needle applicator before soldering. This is what I use.
http://www.alliedelec.com/images/produc ... 177913.pdf

It doesn't technically need to be water soluble flux. If you use a standard rosin flux, just use isopropanol alcohol and an old toothbrush to scrub until you can not feel anymore stickiness.

Also, the link you gave is super expensive for the amount your getting. Try to find a local electronics supply store.

Thanks, I thought the flux is usually inside the core of the solder, so I thought your solder was a special variety.

What commands would you have to add to be able to pipe the sensor values out to the Serial Monitor?

Thanks
Paul