Show HN: Oasis – An open-source, 3D-printed smart terrarium

See the website for a demo video: https://oasis-terrarium.com

This project is an enclosure for growing plants. Features include:

  - high-power LED lighting
  - a built-in water tank and mister
  - fans for airflow
  - temperature and humidity sensing
  - wi-fi connectivity and a web-based interface for control and monitoring (see https://oasis-terrarium.com/docs/usage_guide/#web-interface)

The entire project is open-source:

  - electronics: designed in KiCad
  - 3D models: designed in CadQuery
  - software: written in Rust

I initially started this project during COVID and built a working prototype using a Raspberry Pi and off-the-shelf parts. The first prototype worked, but was pretty rough. Several months ago, I picked up the project again and began a complete re-design. After two rounds of circuit board design and countless iterations of the 3D-printed parts, I'm finally happy with the results. Along the way I learned a lot about electronics design and fabrication, 3D modeling, and Rust.

Happy to answer any questions - thanks for checking it out!

Here are some direct links to parts of the project you may find interesting:

  - demo video: https://oasis-terrarium.com
  - detailed build guide with pictures: https://oasis-terrarium.com/docs/build_guide/
  - interactive 3D model: https://oasis-terrarium.com/docs/3dmodel/
  - detailed info on electronics design: https://oasis-terrarium.com/docs/electronics/
  - 3D-printable models: https://www.printables.com/model/1315117-oasis-smart-terrarium

Show HN: Oasis – An open-source, 3D-printed smart terrarium
github.com

Total cost is roughly $110 USD, but there are a couple caveats to that price:

  - some parts are sold in multiples, so you'll have to buy several even if you only need one for the build
  - I ordered the electronics from JLCPCB where the minimum order quantity is 5 (minimum assembled is 2). At a quantity of 5 assembled, the LED board is ~$12/board and the mainboard is ~$41/board. If you're comfortable with SMD soldering, you can order bare PCBs and parts and do it for much cheaper by assembling only one of each board. You can find some more details here: https://oasis-terrarium.com/docs/electronics/#how-to-get-them. And a history of my JLCPCB orders including costs here: https://oasis-terrarium.com/docs/electronics/#pcb-order-history

With those caveats in mind, the rough breakdown is:

  - custom electronics: $53
  - 3D-printed parts (~600g of PETG): $12
  - other parts: $46

As for build time:

  - acquiring/assembling electronics: this can vary a lot depending on whether you buy assembled or do it yourself
  - 3D-printing: depending on your printer, maybe 2 solid days of printing
  - waterproofing 3D-printed parts: takes ~15 minutes to do and 24hrs for the epoxy to cure
  - final assembly: 30-60 minutes

Thanks!

> To protect the ultrasonic mister from bad firmware frying it, you could probably replace R6 with a sufficiently sized capacitor to make an effective DC block

That is an excellent idea - I'll definitely keep that in mind for a future version.

> I've also had issues with a thermal sensor just reading board temp, best solution is to make the sensor a separate board. Short of that, one can mill slots around it and reduce copper pour to reduce thermal conductivety from the PCB.

I ended up just moving the sensor offboard and as far away from the heat source as I reasonably could. I did consider the milled slots + reduced pour option, but given the amount of heat generated by the LEDs, it seemed best to move the sensor further away.

Most of my time designing hardware is spent trying to find ways to prevent the doofus writing the firmware from releasing the magic smoke. I am that doofus

I like it, but it is not mostly 3-D printed.