The stuff Paludariums are made of


People are often confused what things are all in the paludarium, what they are called and what they do. In this blog post I’ll explain the different components (sub projects if you will) that make up the paludarium today.



A quick overview

In order to get the paludarium working as it works today, I had to run several different projects and put them all together. First I’ll quickly list all the different components:

  1. The Cabinet – The custom-built cabinets that hold the paludarium;
  2. The Paludarium – The glass structure that holds water and air (the paludarium is a closed construction);
  3. The Land part – The part above water. Filled with tropical plants, and for now no animals here;
  4. The Aquatic part – The front underwater part of the paludarium, where the fish live;
  5. The Sump – The rear underwater part. Any excess water from the Aquatic part is dumped here, and the plants living on the background panel get their water from here (and return it there too);
  6. The Waterworks – The board in the cabinet that holds all the plumbing (water valves etc);
  7. The Canopy – The intelligent armature sitting on top of the paludarium;
  8. PaluPi – A standard Raspberry Pi with an RS232 level converter that sits inside the Canopy and handles all the “smart thinking”;
  9. Apollo units – Named after the god of light, there are around 12 of these units inside the Canopy, each handling up to 4 leds, halogens, TLs or fans;
  10. Neptune module – Still under development, this unit controls all pumps, valves etc in the Waterworks;

Quite a list right? Everything in this list had to be tuned to each other in order to work. In the following paragraphs I’ll put in some details around each and every component.


1. The Cabinet

Build to carry over 500KG of weight, the Cabinet is basically just a very slightly modified kitchen cabinet:

The paludarium cabinet as it turned out; TV on the right on a lower section, and room for the paludarium on a higher section on the left.

The paludarium cabinet as it turned out; TV on the right on a lower section, and room for the paludarium on a higher section on the left.

Built to size (exact height and layout) using standard kitchen cabinet equipment. The normal “legs” that raise a kitchen to its correct height have been left out (as they would cause the cabinet to break apart when loaded over a few hundred KGs). Instead the cabinets are sitting on wooden beams that sit directly under the vertical panels. The wooden beams sit directly on the concrete floor. That allows the cabinet to hold extreme pressures. Read more about it here.


2. The Paludarium

The glass structure itself:

The Paludarium v2.0 standing on his reserved spot. Looking good!

The Paludarium v2.0 standing on his reserved spot. Looking good!

This was also built to size by a company specialized in the construction of (custom) aquariums and terrariums. Its dimensions are 1 meter wide, 60cm deep and 120cm high. It features up to 50cm of water inside. There is a divider inside that divides the Aquatic part from the Sump.


3. The Land part

The Land part is the space inside the Paludarium, above water. The main components here are a beach, a waterfall and the background:

Completely filled paludarium. Note how the beaches are half-flooded, exactly how it was planned.

Completely filled paludarium. Note how the beaches are half-flooded, exactly how it was planned.

There is more planning involved in this sub project than you might think: Water coming down the background, has to go back into the Sump. Water pumped though the waterfall may in no circumstance go in the Sump (that would cause the filter to drain the aquatic part over time!).

Also, it was difficult to make all the components using just styrofoam, epoxy resin, silicon glue and natural materials. For more details look here and here. I think it turned out nice though:

non-aquatic part planted as well!

non-aquatic part planted as well!




4. The Aquatic part

This is where the fish live! This part is, together with the Land part, the main attraction:

Looking through the Aquatic part of the Paludarium from the right side.

Looking through the Aquatic part of the Paludarium from the right side.

The first fish are already in there:

Cleithracara maronii (keyhole cichlid) discovering their new world. The blue stripes in the background are Paracheirodon axelrodi (Cardinal tetras)

Cleithracara maronii (keyhole cichlid) discovering their new world. The blue stripes in the background are Paracheirodon axelrodi (Cardinal tetras)

Detailed view of the Aquatic part with the Cleithracara maronii as the main stars :)

Detailed view of the Aquatic part with the Cleithracara maronii as the main stars 🙂

Soon I’ll post some more images of the Aquatic part. Just waiting for my Anableps to arrive!


5. The Sump

the Sump is basically the gutter of the Paludarium. Any excess water (for example when fresh water is added) is spilled over the divider into the Sump. Rainwater should largely hit the background and go into the Sump, and water used to moisturize the background is actually pumped out of the Sump, over the background back into the Sump.

Any excess water in the Sump flows directly into the sewer through a thick pipe:

Detail of the sewer pipe in the paludarium. Any access water will flow straight into the sewer. Note how the water is exactly leveled to the edge of the drain.

Detail of the sewer pipe in the paludarium. Any access water will flow straight into the sewer. Note how the water is exactly leveled to the edge of the drain.




6. The WaterWorks

The WaterWorks sit in the cabinet, and contains most of the plumbing. The Paludarium uses valves, heaters and reverse-osmosis. The Waterworks contains all of this stuff:

The WaterWorks mounted in the cabinet under the paludarium. Almost ready to go!

The WaterWorks mounted in the cabinet under the paludarium. Almost ready to go!

The valves on here will be controlled by the Neptune module.


7. The Canopy

Now here it gets serious. The Canopy is the light armature that holds all lighting, fans and the Paludariums “Brain” (The PaluPi). This Canopy was originally built for the first Paludarium (version 1.0) and was largely reused for the current version 2.0 of the Paludarium.

Looking up into the Canopy, it looks something like this:

The entire Canopy with lights burning (not at 100%). Well almost... I just noticed I burnt a halogen in the bottom left :S

The entire Canopy with lights burning (not at 100%). Well almost… I just noticed I burnt a halogen in the bottom left :S

You can actually see all of the small PCBs sitting inside. Those are the Apollo units. Fans on the right, and top right the PC power supply that is used/abused for all low voltage stuff (the LEDs are run from 5V, the Halogens from 12V).

The actual “brains”, the PaluPi is hardly visible at all. On the image above, it sits directly under the power supply. As it is built into a black housing, it is hard to see. The white thing on the left is the TL ballast that runs and dims the TL lighting.


8. The Paludarium’s brains: PaluPi

PaluPi is the highest level of intelligence inside the Paludarium (maybe the fish are smarter though 😉 ). PaluPi is actually a Raspberry Pi. It is connected to the internet via ethernet, and talks to all electronic components using the serial port. In order to be able to do this I mounted a small PCB on the Pi:

Raspberry Pi with my serial communication "level converter". It still fits in the RPi's housing, so I'm happy.

Raspberry Pi with my serial communication “level converter”. It still fits in the RPi’s housing, so I’m happy.

For more details on how the serial communication works, see here.

So what do the brains do? A lot of things. I’ll list some of the highlights here:

  1. Fetch data from the La Selva Biological Station (see here for more details);
  2. Store the La Selva data in a local database;
  3. Use the data in the Database to calculate values the Canopy needs to do lighting etc and send them out;
  4. (future) serve a website around the real-time and stored data.



9. Apollo units

The Apollo units are named after Apollo, the god of light. The Apollo units are extremely basic controllers. They are based on Atmel AVR controllers of the ATtiny2313 type. They feature 4 PWM outputs and optional 4 digital outputs. The units each have a unique address so they can be accessed individually. They also have several group addresses so when sending a group command all units will be listening in. This is what they look like in detail:

AVR Controllers inside the Canopy. Note the grey cable looping through all controllers to form a shared serial bus.

AVR Controllers inside the Canopy. Note the grey cable looping through all controllers to form a shared serial bus.

There are four subtypes of them:

  • LED – These Apollo’s dim four 1W power LEDs;
  • HALO – These Apollo’s dim four Halogen light (20W each) and look very much like the LED units;
  • FANS – This is actually a single Apollo unit inside the Canopy. It controls three fans and the two TLs;
  • RGBs – These Apollo’s have a different PCB. They are specific designed for high power RGB LEDs (3x 1W) for night lighting etc.

These little units only have 2KB (yes – KILObyte) of flash memory onboard. Needless to say that they are simple, direct and bug free. They have already done 2 years of service in Paludarium 1.0, and now continue their work (with only slightly adjusted software) in version 2.0 of the Paludarium.


10. Neptune unit

The Neptune module is under construction:

The Neptune module being prototyped. Connected to a level converter (on top) to allow a normal PC to talk to the module.

The Neptune module being prototyped. Connected to a level converter (on top) to allow a normal PC to talk to the module.

It is like an Apollo unit on steroids. It is based on an Atmel AVR Mega32 controller. This controller is very much bigger, and can also read analog values. This is the one big single unit that will control and measure everything necessary and it does not sit in the Canopy, but close to where it needs to function: Next to the WaterWorks inside the cabinet under the Paludarium.

So what does this unit do? It does the following things:

  • Control the three water valves (tapwater, rain, reverse osmosis);
  • Control the aquatic heater;
  • Control the pump that moisturizes the background of the Land part;
  • Control the CO2 valve;
  • Control the mistmaker;
  • Control the RGB light strip under water;
  • Measure aquatic temperature;
  • Measure air temperature and humidity;
  • Measure pH values;
  • Measure water conductivity.

Quite an impressive list, right? The above things are done using several technologies. For starters, there are 8 relays mounted on the PCB that can directly switch mains voltage. That allows the Neptune module to directly switch valves, pumps etc.

The RGB strip is controlled using powerFETs (IRF540’s), just like the Apollo units do. These FETs connected to PWM output allow a very detailed control of Red, Green and Blue (each in 256 steps of intensity).

Finally the Neptune module measures things. It uses the internal A/D converter in the Mega32 for all measurements but the air temperature and humidity. Those are measured by a specialized chip (Sensirion SHT11) and are read digitally by the Neptune module (and then sent back to the PaluPi).


Finale

Most of the sub projects are ready or almost ready. They have all been integrated into each other, and the Paludarium now works for the larger part. Inhabitants are already present! There are two main things that remain to be done:

  1. Completion of the Neptune module and adding some code in the PaluPi to support it;
  2. Construction of a web server on the PaluPi that delivers buttons, graphics etc. on the Paludarium.

Still a lot of work, but the payback is largely already there…. Right now the Paludarium is a real treat to look at!

2 Responses to The stuff Paludariums are made of

  1. Prachtig Project 😀 Ben momenteel ook bezig met een paludarium, en heb ook een volledig regelsysteem gemaakt (bij mij gebaseerd op een atmega328p-pu. Toen ik begon was ik een volledige leek op het gebied van programmeren, maar heb de code nu zo goed als af 🙂 Ik vroeg me af, publiceer je je code ook ergens? For teaching’s sake?

    • Sorry voor het late antwoord! Nee de code is nergens gepubliceerd. En met speciale reden… Ik wil voorkomen dat mensen de code gaan proberen te gebruiken en dat daar dan 1000 vragen uitkomen… De code is zo specifiek voor mijn bouw, ik verwacht niet dat iemand dit zo ooit gaat nabouwen.

      Als je iets specifieks zoekt in de code, laat het weten!

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