Electronics #

See below for details on the custom-designed electronics for this terrarium.

There are essentially three options for obtaining the electronics:

• Order bare PCBs (from OSH Park, JLCPCB, PCBWay) and parts (digikey, mouser, etc) and solder them yourself. This can be a good option if you have experience with SMD soldering.
• Order fully-assembled PCBs from JLCPCB. This can be a good option if you’d prefer not to solder the boards yourself, but it can be expensive for small order quantities.
• Sign up to buy a kit if/when they become available. I don’t have any immediate or concrete plans to sell these, but will consider it if there’s enough interest.

Mainboard #

The mainboard contains:

• a microcontroller with builtin wifi (esp32-c3)
• led driver
• 18v to 3.3v voltage converter
• ultrasonic mister driver
• fan driver
• usb connector for updating firmware

Find the KiCad design files here: https://github.com/justbuchanan/oasis/tree/main/pcb/main.

Schematic #

3D Renders #

Top View

Bottom View

Ledboard #

The LED board is very simple - it’s 5 LEDs wired in series mounted on an aluminum board to act as a heatsink.

Find the KiCad design files here: https://github.com/justbuchanan/oasis/tree/main/pcb/ledboard.

In order to connect to the mainboard, the ledboard needs a 2-pin JST PH connector (for example https://www.amazon.com/dp/B01DUC1O68) soldered onto it.

Schematic #

3D Render #

SHT30 Sensor Board Wiring #

The sht30 sensor board comes without a cable. You’ll need to solder a standard 4-pin connector cable in order to plug it into the mainboard.

PCB Order History #

v0.1 all-in-one board - Feb 11, 2025 #

Single-board design - esp32, leds, sht30 temp/humid sensor, and everything else all on one board.

A lot of the board was assembled by JLC, but the following parts were purchased and assembled separately (in total, probably $17 worth of parts per board):

• led driver
• leds
• sht30 temp/humid sensor
• sht30 bypass capacitor

Files: https://github.com/justbuchanan/oasis/tree/main/pcb/fabricated-boards/v0.2

Pricing #

note: this price info is what I was charged by JLC, it does not include the components I sourced and assembled myself (mentioned above).

• total: $140
  • merchandise total: $89
  • shipping: $38
  • sales tax: $13

v0.2 ledboard - March 16, 2025 #

Based on the poor thermal performance of the all-in-one boards, I decided to do a major redesign and put the leds on their own board, made out of solid aluminum. The electronics are on their own board.

This order is for 5x 1.6mm thick boards for the leds. Price/board = $6.84. This price doesn’t include the 5 Cree XT-E LEDs or the connector cable soldered on.

Files: https://github.com/justbuchanan/oasis/tree/main/pcb/fabricated-boards/ledboard-v0.3

Pricing #

• total: $35
  • merchandise total: $14
  • shipping: $18
  • sales tax: $3

v0.2 mainboard - March 21, 2025 #

Files: https://github.com/justbuchanan/oasis/tree/main/pcb/fabricated-boards/mainboard-v0.3

5 Control boards. Fully assembled except the 2 4-pin headers. Price/board = $40.6.

• total: $203
  • merchandise total: $153
  • shipping: $29
  • sales tax: $21

Power Consumption #

Power consumption of the electronics was measured using a bench power supply set to 18V. Here are the results: