How rootoftwo Used Eight R PRO-1 mmWave Sensors in Anyspace? Whatever. at MOCAD Detroit, Plus a Free 3D Printable Mount
From July 11 to September 27, 2026, the Museum of Contemporary Art Detroit (MOCAD) hosted Anyspace? Whatever., a solo exhibition by Detroit studio rootoftwo. rootoftwo is Cézanne Charles and John Marshall. The show looked at the systems that quietly shape civic life: surveillance networks, algorithmic decision-making, and the data infrastructure built into so-called smart cities.
At the center of the show was The Rotunda, a pavilion that listens and talks back. To know where visitors were, rootoftwo installed eight Apollo R PRO-1 PoE mmWave multisensors in custom hexagonal mounts. No cameras. Then they released the mount design as open source, so anyone can print one.
What was Anyspace? Whatever.?
The exhibition turned MOCAD's front gallery into a place for civic imagination and collective play. Instead of treating the smart city as inevitable, rootoftwo asked visitors to argue with it.
- The Rotunda. A 17 x 17 x 17 foot voice-interactive pavilion based on Albert Kahn's 1933 Ford Rotunda, wrapped in black and white dazzle camouflage meant to confuse machine vision.
- 463NCY. A cooperative cyberpunk tabletop game for 2 to 6 players on a responsive RFID board drawn from Oswald Mathias Ungers' unbuilt 1975 Roosevelt Island housing plan.
- Storycubes and The Moment. Plywood seating cubes with QR codes that open an AI-generated short film series contrasting cyber-dystopian megacities with solarpunk alternatives.
- The Signals Archive, plus open AI labeling using the Dubai Future Foundation's Human-Machine Collaboration icons.
More on the thinking behind it is on rootoftwo's project page and in ART AFRICA Magazine.
Watch the exhibition
Video by Evan Zott for rootoftwo. Watch on Vimeo.
How The Rotunda works
rootoftwo describes The Rotunda as an asynchronous people's assembly. Here is what a visit looked like.
- Outside. Four loudspeakers broadcast a patriarchal voice reading polished, AI-generated slogans about data collection and efficient, tech-driven city living.
- Stepping in. The moment you walk through the doorway, the outside announcement cuts off. One of four custom AI personas greets you.
- Starting a conversation. Stand near the center of the room for two seconds and speak. The AI asks permission to ask you a question about urban life, privacy, or technology.
- Privacy check. Ask about your privacy rights and the system explains that no audio is saved or uploaded to the cloud. Only a written transcript is sent on for review.
- Answering. Once you consent, the AI asks a question tailored to its persona, waits while you answer, thanks you, and says goodbye.
- Reshaping the broadcast. Transcripts that pass moderation join the growing collection of visitor responses. Over the weeks of the show, the outside speakers shift away from the corporate script to a female elder's voice reading back the community's words, concerns, and hopes.
Steps two and three depend on knowing where people are, which is where the sensors come in.
Eight R PRO-1 sensors, no cameras
Each R PRO-1 in The Rotunda ran two mmWave radars: an LD2450 for multi-zone position tracking and an LD2412 for still presence, so someone standing and talking still counts as there. The eight sensors were laid out in two groups.
- 6 perimeter sensors at the wall-ceiling junction, spaced at 60 degree intervals and set 15 degrees off-axis from the doorways. They angle toward the center for room-wide entry tracking and for locating people when only a few are inside.
- 2 overhead sensors above the center of the ceiling, rotated 90 degrees from each other. One tracks north to south, the other east to west. When a crowd blocks the perimeter sensors' line of sight, these two keep the center zone accurate.
That center zone is the one that starts a conversation. It is also why the room can tell the difference between someone passing through and someone who stopped to talk.
Radar fits a show about surveillance. It reports positions, not pictures. There is no face to match and no video feed to leak, and the sensors themselves send nothing to the cloud. The Rotunda's dazzle pattern is designed to fool machine vision. The sensors inside aren't looking at it at all.
Calibrating the sensor array
Eight sensors only help if they agree on where a person is. rootoftwo built a corner reflector rig from rigid foam core covered in smooth aluminum tape. Radar bounces strongly off that shape, which makes it an easy target to find.
They hung the reflector from the ceiling grid at known coordinates and used those points to calibrate the combined sensor data. The result was about 15 mm theoretical accuracy with software offsets, and about 40 mm practical accuracy in the room. The small gap comes from the floor not being perfectly perpendicular to the sensors.
Before any of it went into the museum, they tested the layout on a studio mockup they call the Fauxtunda. June Walker, a software developer at Minima, built the app used to test and tune the sensors.
The open source hexagonal R PRO-1 mount
The R PRO-1 mounts in a single gang box or on a ceiling. The Rotunda needed something else: a housing that matched the pavilion's hexagonal ceiling grid and could be aimed precisely. So rootoftwo designed the Hexagonal Sensor Mount for Apollo R PRO-1 Multisensor, and they have released it for anyone to use.
Specs
- Target sensor: Apollo R PRO-1, PoE, with LD2450 and LD2412 radars
- Shape: geometric hexagonal shell, two pieces, top and bottom
- Material: PA-11 nylon printed with HP Multi Jet Fusion (MJF), dyed black. Chosen so the shell would not warp, soften, or crack from the board's steady warmth over months of continuous running.
- Mounting: built-in 1/4"-20 thread socket that fits standard camera ball mounts, for aiming on any axis
Files
- STEP file with both pieces of the mount, for editing in your CAD program
- STL files for the top and bottom
- 3MF files for the top and bottom
Download the hexagonal R PRO-1 mount files from rootoftwo
Mounting hardware rootoftwo used
- Small Parts #3-24 steel thread rolling screws for plastic, 3/8" long, black zinc, Phillips pan head
- INNOREL C19 mini ball head with a 3/8" to 1/4" adapter
- 3/8 inch male screw flange wall mount adapter, aluminum, with self-tapping screws
License and credit
The 3D files, drawings, and documentation are released under CC BY-NC-SA 4.0. You are free to share and remix them for non-commercial use. Credit rootoftwo, link to the license, and note any changes. If you publish a remix, release it under the same license. If you re-host the files on Printables, MakerWorld, GitHub, or anywhere else, rootoftwo asks that you include this credit:
Design Credit: Hexagonal Sensor Mount for Apollo R PRO-1 Multisensor by rootoftwo (John Marshall & Cézanne Charles), designed for Anyspace? Whatever. at the Museum of Contemporary Art Detroit (MOCAD). Licensed under CC BY-NC-SA 4.0.
If you print one, post a photo on the Apollo community forum. We would like to see it.
Why PoE works for installations
Power over Ethernet puts power and data on one cable. With eight sensors in a ceiling, that means one clean run to each, a wired connection that doesn't compete with visitors' phones for Wi-Fi, and no wall adapters to hide. The R PRO-1 is 802.3 PoE compliant, and also runs on Wi-Fi with USB-C power when a cable run isn't practical.
R PRO-1 at a glance
- LD2450 mmWave radar for multi-target position tracking and zones
- Optional LD2412 mmWave radar for still presence
- LTR390 ambient light and UV sensor
- Two addressable RGB LEDs and a piezo buzzer
- 802.3 PoE, or Wi-Fi with USB-C power
- Bluetooth, including Bluetooth proxy support
- Rear expansion port for an optional SCD40 CO2 module
- ESPHome firmware, open source on GitHub, listed on the ESPHome devices site
Full specs are on the R PRO-1 product page. Setup help is in the R PRO-1 wiki FAQ, and our R PRO-1 launch post covers why we built it.
Local control, in a museum or at home
The things that made the R PRO-1 fit this show are the same reasons people put it in their homes. It runs ESPHome, the open source firmware project that lives under the Open Home Foundation. It shows up in Home Assistant on its own. It works without an account, a cloud server, or a subscription.
That open, community-built foundation is what let an artist take a sensor made for a hallway, build eight of them into a pavilion, and point them at a question about who gets to watch whom. Build, learn, automate.
Thank you, rootoftwo
Thank you to John Marshall and Cézanne Charles for building the R PRO-1 into this work and for sharing the mount with everyone. Thanks to June Walker and Minima, to MOCAD for hosting the show, and to Evan Zott for the video. Anyspace? Whatever. was supported by The Andy Warhol Foundation and the Teiger Foundation, with additional support to the artists from the Creative Capital Foundation, the Patrick J. McGovern Foundation, the US Regional Arts Organizations, and the John S. and James L. Knight Foundation. Production support came from Donut Shop, Minima, Modern Sign Studio, and Detroit Independent Holdings.
Frequently asked questions
What was Anyspace? Whatever.?
Anyspace? Whatever. was a solo exhibition by the Detroit studio rootoftwo at the Museum of Contemporary Art Detroit (MOCAD). It looked at surveillance, algorithmic decision-making, and data extraction in so-called smart cities. Its centerpiece, The Rotunda, was a voice-interactive pavilion where visitors talked with a custom AI system and gradually rewrote the message its outside speakers broadcast.
Who is rootoftwo?
rootoftwo is the creative and civic studio of Cézanne Charles and John Marshall, based in Detroit. Their work mixes science, technology, and creative practice to question standard stories about progress, with a focus on privacy, agency, and consent.
When and where was the exhibition?
Anyspace? Whatever. opened July 11, 2026 in Gallery 1 of the Museum of Contemporary Art Detroit, 4454 Woodward Avenue, Detroit, Michigan, and ran through September 27, 2026.
How many R PRO-1 sensors were used in The Rotunda?
Eight. Six perimeter sensors sat at the wall-ceiling junction at 60 degree intervals, and two overhead sensors were mounted above the center of the ceiling, rotated 90 degrees from each other.
How did the R PRO-1 sensors work in The Rotunda?
Each R PRO-1 combined an LD2450 radar for multi-zone tracking with an LD2412 radar for still presence. Together they tracked visitor movement. Stepping inside cut off the outside broadcast, and standing near the center of the room for two seconds while speaking started a conversation with the AI.
How were the sensors calibrated?
rootoftwo built a corner reflector rig from rigid foam core covered in smooth aluminum tape and suspended it from the ceiling grid at known coordinates. That gave them reference points to calibrate the combined sensor data. They report about 15 mm theoretical accuracy with software offsets and about 40 mm of practical accuracy in the space.
Can I 3D print the hexagonal R PRO-1 mount?
Yes. rootoftwo released the Hexagonal Sensor Mount for Apollo R PRO-1 Multisensor as open source. The files include a STEP file with both pieces, plus STL and 3MF files for the top and bottom. The originals were printed in PA-11 nylon using Multi Jet Fusion and dyed black.
What license are the mount files released under?
The 3D files, drawings, and documentation are released under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license (CC BY-NC-SA 4.0). You can share and remix them for non-commercial use, as long as you credit rootoftwo and release any remix under the same license.
What hardware do I need to mount it?
rootoftwo used #3-24 thread rolling screws for plastic, 3/8 inch long, a mini ball head, and a 3/8 inch flange wall mount adapter. The mount has a built-in 1/4"-20 socket, so it works with standard camera ball mounts for aiming.
Does the R PRO-1 use a camera?
No. The R PRO-1 senses people with millimeter-wave radar. It does not capture images or video, so there are no faces to store or leak.
Why use PoE sensors for an art installation?
Power over Ethernet carries power and data on one cable. For a months-long installation with eight sensors, that means one clean cable run per sensor, a wired connection that does not compete with crowded museum Wi-Fi, and no power adapters to hide in the ceiling.
Does the R PRO-1 need the cloud or a subscription?
No. The R PRO-1 runs ESPHome firmware and is controlled 100% locally. There is no cloud account and no subscription.
Does the R PRO-1 work with Home Assistant?
Yes. The R PRO-1 is built on ESPHome and is discovered automatically by Home Assistant. Apollo is a Works With Home Assistant partner, and the R PRO-1 carries the Made for ESPHome badge.
Exhibition photos courtesy of rootoftwo. Video by Evan Zott. Hexagonal mount design by rootoftwo, licensed under CC BY-NC-SA 4.0.
Apollo Automation designs, engineers, and manufactures privacy-first, locally-controlled smart home sensors in Versailles, Kentucky. Every product features 100% local control with no cloud dependencies or subscriptions required. Apollo is a Works With Home Assistant partner, Made For ESPHome certified, Works With Homey certified, a BBB Accredited Business, and the second official commercial partner of the Open Home Foundation. Learn more at apolloautomation.com.
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