I thought it was time for me to introduce in this thread my new terrarium. It will be more 'techy' than 'planty', so if you are expecting mainly pictures of plants here, well, you'll be pretty disappointed.
I started over 6 months ago with this new project, as I had to stop growing carnivorous plants and put away my former terrarium. I hope it will meet the same success as its elder brother. The previous one was already running with a RPi, but its use wasn't maxed out.
Here we go, the result as it was a few weeks ago:
Basically, it's a small terrarium (65x55x65) dedicated to grow highland carnivorous plants, but also, to answer my needs as a grower: autonomous, tailored set up with remote monitoring. Handy, transportable by one person, and good-looking (enough). Almost bearable in a living room, i.e, not giving away too quickly a vibe of 'eccentricity'.
But behind the scene, it's a different kettle of fish.
I bought the glass panes, and started to drill them. The holes will be used for aquarium tubing:
Then starting with actual panes:
Watering the area of interest:
The silicone used to joint the terrarium together:
A bit messy:
Top pane set up. I stuck the first rail for sliding panes. Wait of 24h. Then final jointing and installation of the through-tank connectors.
48h wait, and leak test :
I built a small tank made of 2 cm styrofoam to contribute to insulate the cooled water from the outside of the terrarium. The aim was to prevent cold losses and reduce outside condensation on the window:
Second profile rail drying:
As a side note, the bottom profile rail is smaller than the top one, allowing easy removal of the sliding panes :
Slicing off a gutter, so to make support for gratings :
To water the plant wall, I set up a pierce hose on top of it:
Same goes with the tree fern panels:
I made a tank for the fogging system, as well as two shelves (one for the tank, one for the watercooling radiator):
Now, about the lighting system.
In short, I wanted LEDs, as they have more opportunities for playing around. They can be dimmed and can have precise wavelengths. So it's possible to roughly mimic sunrise/sunset.
I used several small ones instead of few big ones because I wanted passive cooling (silent installation), and not being forced to have fans running on top of big LEDs to have them cooled down.
I bought MK-R LEDs and no-name ones (blue: 440-445, 430-435nm and red: 660nm), all powered around 4W.
The MK-R as I received them:
The first step is to mount the MK-R on their individual PCB:
I spread solder paste on the PCB:
I did reflow soldering, by making solder paste melt between the PCB and the LED. Information about the specifications on how to carry out this process can be found on the MK-R datasheet:
Useful thermometer (there wasn't any LED on the pan at the time I took this picture):
Then, I drilled and mounted some heatsinks together:
I added some tin to make the connecting easy:
Thermal paste and other tools:
(there was actually a mistake in this wiring at the time of the picture)
Warm effect (morning):
A bit of an overkill, but in case, some fans to help the heatsinks dissipate the heat:
How the lighting system is fixed. Inspired from aquarium hobby:
Funny trick - how to adjust the height of the lighting system:
The fusebox, when I was still tinkering with the RPi:
The cooling system (below 13°C at night and no higher than 25°C during the day):
The cooling unit:
The watercooling radiator:
The heating system is based on a heating pad and a fan (that I also use for the fogging system, and all day long to promote air circulation):
The fogging system, with classic mist makers:
The watering system is composed of 4 nozzles:
And a pump:
And for the geeky part, the Raspberry Pi to rule them all. This is the micro-controller (small computer) which manages all the devices related to the terrarium. Good news, you can do almost everything you want. Bad news, the RPi won't program itself:
I connected several sensors and other hardware resources to it. To have something neat, I designed a printed circuit board (PCB). Yep, the schematic is quite messy:
Rendering this after milling (a friend of mine milled it for me):
I soaked it into liquid tin:
Then, components' supports:
In the end, more or less:
A webcam on top of the terrarium:
Which gives this kind of snapshot (I consider doing time-lapse, as soon as I don't have plastic bags on top of some plants. I removed them for the sake of the pictures):
How to command the devices ? Using relays. I had some that I very recently replaced with wireless (radio/433 Mhz) ones.
A receiver (to copy radio signals, or for instance, coupled with a remote controller to switch off the terrarium):
And not-so-useful remote controllers, as everything is managed by the RPi.
They bypass the RPi (as they send the same signals as the RPi do), so, I can turn on/off a device without having to use the RPi, and without tampering with the rules I set up. I just have to ensure that I put the device back in its original state after I'm done operating it.
About coding, I had a first version which was working but far from being optimised. The crucial upgrade was made possible thanks to Clément Lefranc, who gave me his entire code. He is the one who takes the credit.
Thanks to his gesture, I could start from a working base that I adapted to my own needs.
As you might be assuming, I have developed a website to better introduce the terrarium. Almost finished with it, just left with a few things to correct. It will be more convenient to look up for any information related to the terrarium, as I'm afraid there are too many pictures on this topic.
But in case of major update, I'll make sure to put the info into this topic as well, so that the gist is always presented here.
That was all for the initial investment. Then, what is interesting is to watch how the plants will react to all this attention. Especially in the long run, as, when it comes to growing, that is the only thing which matters in my opinion. And the more it is complex, the more it's likely to break down somewhere. But I'll keep you updated. At least, the start is successfully completed: believe me, it could have not been so.
I hope it might give ideas to some of you.
P.S: I still can't get my hand on the 'preview button'. Has it totally disappeared? Is there any way to have it back?