A terrarium is a little piece of the living world captured in a small enclosure you can pop on your desk or coffee table at home. If you want to keep it as alive as possible, though, you might like to implement some controls. That’s precisely what [yotitote] did with their smart terrarium build.
At the heart of the build is an ESP32 microcontroller. It’s armed with temperature and humidity sensors to detect the state of the atmosphere within the terrarium itself. However, it’s not just a mere monitor. It’s able to influence conditions by activating an ultrasonic fogger to increase humidity (which slightly impacts temperature in turn). There are also LED strips, which the ESP32 controls in order to try and aid the growth of plants within, and a small OLED screen to keep an eye on the vital signs.
It’s a simple project, but one that serves as a basic starting point that could be readily expanded as needed. It wouldn’t take much to adapt this further, such as by adding heating elements for precise temperature control, or more advanced lighting systems. These could be particularly useful if you intend your terrarium to support, perhaps, reptiles, in addition to tropical plant life.
Indeed, we’ve seen similar work before, using a Raspberry Pi to create a positive environment to keep geckos alive! Meanwhile, if you’re cooking up your own advanced terrarium at home, don’t hesitate to let us know.
I’m doing something similar for my mushroom grow-tent :)
Culinary or recreational?
Please be careful with these things.
I’ve read a few horror stories of animals dying because of a simple software glitch, or a faulty sensor. Even if your terrarium only has plants, you’ve probably put a lot of time and effort into making something beautiful, and it would bee a shame to see it destroyed because of a faulty sensor or software glitch.
Similar for 3D printers. A common fault was that the temperature sensor got pulled out of the heater, and the heater never turned off, resulting in the whole thing catching fire and possibly burning down your house. After that happened a few times, software loops were added to judge whether the input from the thermometer made sense (I.e, does the temperature go up when the heater is turned on?)
In general, always analyze the whole system (both hardware and software) and consider what happens if any of the parts fail. Also, If you want to use software. Making the software more robust is a fun programming exercise.
As they say, you are much better off when you design for the rainy days.
A trick on the hardware side that I used for my fish tank was to use two smaller heaters that together can provide enough heat for the whole tank, but not enough to overheat the tank individually.
That way if one thermostat failed on, the other heater would just regulate accordingly and prevent cooked fish from a single point of failure.
And if one thermostat fails “on”. Would you notice it?
The lilly-go t-relay works really well for these applications. I have a few setup for plants and greenhouse controls.
I built a similar thing with a web interface about 6 years ago and it’s been running stable ever since and luckily hasn’t flooded my living room yet :D
https://github.com/fehlfarbe/terraesp