Hayden Geiger

// Shipped · 2025

Microfarm prototype & anemometer

A first-year ENED team project for the Pine Ridge Reservation — a 3D-printed microfarm that breaks the wind for a small garden. I did the CAD and printing and built the test rig, including an anemometer I made from scratch (my own Altium board and a printed impeller) to measure how much the wind dropped inside.

Fusion 3603D-printedAltium anemometerDC-motor sensor
The finished project on a windowsill — the 3D-printed microfarm with black wind mesh on its frame, and the printed anemometer beside it.
The printed microfarm and the finished anemometer

What it is

A first-year design project (ENED 1100). Our team was assigned the Pine Ridge Reservation, where thin soil and constant wind make it hard to keep a small garden alive. We landed on a microfarm — a small enclosed planter that blocks the wind and holds the soil in place. To see whether the idea held up, I printed it at 1/10 scale.

My part

It was a group project. I took the physical build and the electronics — I modelled the microfarm and the test hardware in Fusion 360, printed the prototype, and put together the rig we used to find out whether the enclosure actually cut the wind.

The anemometer

The whole idea hinges on one question: does the structure really slow the wind down where the plants sit? To answer it I needed a wind reading, so I built my own anemometer instead of buying one.

A 3D-printed impeller rides on a small DC motor. Spun by the wind, the motor runs backwards as a generator — faster air, higher voltage. An ESP32 on a board I designed in Altium (I had it fabricated and soldered it myself) reads that voltage, shows it on a small round display, and logs it over serial so I can average it.

It only reads volts, not real metres per second. That was fine here: same sensor, same distance, inside the farm against outside it.

Testing and results

I put a fan a foot from the printed farm and took readings inside and outside the walls, five runs each way.

  • Outside: about 0.64 V on average
  • Inside: about 0.18 V

So the reading dropped by roughly 70% once it was inside the enclosure — which is what we were hoping to see.

What I’d change

The signal was noisy. A bare DC motor is a rough way to sense wind, and the trend line through the data was weak, so I trust the direction of the result more than the exact number. Another time around I’d calibrate it against a known wind speed, or just use a real sensor, so it reads in actual m/s. The erosion and durability tests never happened for real — a 1/10 plastic model wouldn’t wear the way the full-size farm would.

// Drawings

Schematic and stackup
Altium PCB layout of the anemometer control board, two-layer, with traces in red and blue.
Anemometer board — PCB layout
The wind test in progress — a fan in the foreground aimed at the mesh-wrapped microfarm, the anemometer held over it, with a breadboard of electronics alongside.
The wind test — anemometer logging inside the farm, a fan one foot away
The anemometer on a workbench — the bare control board above, and the assembled unit below with a printed ducted impeller and a round display on the back.
The anemometer — printed impeller, DC motor, and a round readout
The 3D-printed microfarm with black wind mesh stretched across its top frame on printed posts.
The microfarm with wind mesh on the frame
Bench build — the printed anemometer body, the fabricated control boards from JLCPCB, an ESP32 dev board, and a breadboard of test wiring.
Bench build — fabricated boards (JLCPCB), an ESP32, and the printed anemometer
Altium 3D render of the anemometer control board — an ESP32 module across the centre, pin headers down both sides, and a two-pin power connector.
Anemometer control board, in Altium
Fusion 360 render of the 1/10-scale microfarm — a caged open-top enclosure with corner posts and a serpentine coil across the floor.
The microfarm, modelled in Fusion 360

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