HOLOCUBIC — TINY 'HOLOGRAPHIC' CUBE DISPLAY ON ESP32 (6.7K STARS)
A coin-sized ESP32 board projects a floating image inside a transparent cube using a beam-splitter prism and a 240×240 screen.
DisplaysOpen-hardware
Built withESP323D printing
- difficulty
- ●●●●○
- time
- a weekend-plus
- license
- GPL-3.0
- repo
- repo FINISHED6,731 stars
●●●●○ · a weekend-plus · GPL-3.0 · 6,731 stars · repo FINISHED
WHAT YOU’LL NEED
Jump to section
COMPAREE VERDICT
HoloCubic is a desktop curiosity that uses a beam-splitter prism to reflect a tiny LCD into the centre of a clear cube, creating the illusion of a floating image. An MPU6050 IMU lets you control it by tilting — no buttons. The effect is striking in person, but this is not a hologram in the physics sense; it is a mirror trick, and the viewing angle is narrow. The project became famous because the creator built it in a single weekend and posted a polished video, but replicating that timeline assumes you already know how to order PCBs with SMT assembly, work from Altium design files, and debug ESP32 firmware. The repo has everything you need to manufacture the boards and the enclosure, but the documentation is thin and in Chinese. The single biggest trap is the prism: it is a 25.4 mm cube beam-splitter that you buy separately (the README suggests Taobao, about 80 RMB) and glue on with OCA film — ordinary glue seeps under the screen. If you have never ordered a custom PCB or soldered 0402 components, this will be a frustrating first project. If you have, and you want a tiny desk ornament that surprises people, this is a well-executed build with a strong visual payoff.
IN THE REPO
GOOD TO KNOW
- —Two PCB designs (Naive and Ironman, Altium sources), firmware, an LVGL simulator and image converter, and four enclosure versions (STEP for Naive and Metal, STL for Bilibili and Ironman; the Metal one is meant for CNC) are in the repo.
- —There is no separate BOM file — the parts list is inside the Altium schematics, with no supplier links or prices.
- —There is no English build guide. The README is brief and in Chinese, and assembly assumes you know how to order PCBs and source SMT components.
- —The licence is GPL-3.0, which permits commercial use but requires derivative works to remain open source under the same licence.
- —The beam-splitter prism is not 3D printed — the README specifies a 25.4 mm cube prism, bought separately (Taobao, about 80 RMB).
Parts to buy
6 itemsFrom our check of the build. Exact quantities and part numbers are in the creator’s BOM.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Videos
Tiny Holo Cubic Display (Data Slayer)
A community build video by Data Slayer showing the cube in action. The creator's original video is on Bilibili (in Chinese): bilibili.com/video/BV1VA411p7MD.
More builds like this
All projectsGallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the README (The README is short and in Chinese. Use a browser translator.)
- 2.Review the BOM and source the prism(The parts list is inside the Altium schematics in 1.Hardware. For the prism, the README specifies a 25.4 mm cube beam splitter — search Taobao or AliExpress for that size.)
- 3.Order the PCB with assembly(Export Gerbers, BOM and pick-and-place files from the Altium projects (Naive or Ironman version), upload to JLCPCB or PCBWay, and use their SMT assembly service. Hand-solder the remaining parts when it arrives.)
- 4.Compile and flash the firmware(The firmware is in 2.Firmware/HoloCubic-fw (Arduino framework; a platformio.ini is included). The README says you must edit the ESP32 Arduino core's SPI.cpp so the HSPI MISO pin is 26 instead of 12, otherwise the board will not boot with the screen and SD card.)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
KNOWN ISSUES
- The beam-splitter prism is not on the PCB — buy a 25.4 mm cube beam-splitter prism separately (the README points to Taobao, about 80 RMB) and fix it with OCA film, because liquid glue seeps under the screen and leaves marks.
- There is no separate BOM spreadsheet — the part list lives inside the Altium schematics, so you need Altium (or a viewer/converter) to extract it. If you have never cross-referenced datasheets, budget time for this.
- The board uses small surface-mount parts around the ESP32-PICO-D4 module. Unless you are experienced with fine SMD soldering, use a PCB fab's assembly service and hand-solder only what they cannot place.
- There is no step-by-step build guide in English. The README is short and in Chinese, and the rest is reading the Altium files and the firmware. Expect to spend as much time researching as building.
- Tilt control comes from the MPU6050 emulating encoder input; if it does not feel right, adjusting it means editing and reflashing the firmware, and the README warns the published code is a rough template.
- The display is a 1.3-inch 240x240 ST7789 LCD; check the module's pinout against the schematic before ordering.
Is this an actual hologram?
No. It is a beam-splitter illusion — a 25.4 mm cube beam-splitter prism sits on the LCD and reflects the image so it appears to float inside the cube. The effect only works from certain angles, and there is no 3D depth. It is the same principle used in Pepper's Ghost stage tricks.
Can I buy a kit with all the parts?
There is no official kit from the creator. The README mentions that he authorised a friend's Taobao shop (Xikii) to produce a small batch of the Ironman version hardware. Otherwise, you order the PCBs from the Altium files and source the parts yourself.
Do I need to know Chinese to build this?
It helps. The README and the original Bilibili video are in Chinese. Browser translation works for the text, but part numbers and firmware comments are easier if you can read some technical Chinese or are comfortable cross-referencing datasheets in English.
How long does the battery last?
There is no battery in the design — HoloCubic runs from its USB-C port. Running it portable would mean adding your own battery and charging circuit.
Can I use a different microcontroller?
The firmware is tightly coupled to the ESP32-PICO-D4 and the ST7789 driver. Porting to another chip would mean rewriting the display and IMU code. Possible, but not a weekend project.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
The creator says he built it in a single weekend, the repo has two PCB versions, and the only guide is a Chinese README. If you have built one, where did you source the 25.4 mm beam-splitter cube and how long did assembly actually take?
Zhihui Peng (稚晖君)
Zhihui Peng is a hardware engineer and maker known for highly polished open-source electronics projects. HoloCubic was built in a single weekend as a desktop curiosity and posted with a cinematic video, which went viral in the Chinese maker community and brought the project to 6.7k GitHub stars.
Keep building — related projects
Same category or platform, picked by how close they are to this build.
FULL CADSmartKnob — open-source haptic input knob with software-defined detents
Open-hardwareFor advanced builders
FULL CADBuild your own e-paper smartwatch for 60 dollars — the battery lasts a week
Open-hardwareFor intermediate builders
FULL CADYou can build a screen that draws pictures with air bubbles
DisplaysFor advanced builders
FULL CADYou can make the LEGO Game Boy actually play games
Open-hardwareFor advanced builders
FULL CADSATURNIX: a 3D printed Raspberry Pi camera that shoots RAW and looks like a film prop
Open-hardwareFor advanced builders
FULL CADYou can build your own Enigma machine
Open-hardwareFor intermediate builders
DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM2mo agoedited
Practical notes from our verification: the repository has not changed since 2023 and the README, in Chinese, is the only documentation; the creator's own video is on Bilibili. The PCB files are Altium, not KiCad, and there are two board versions (Naive and Ironman) plus four enclosure designs — the Naive case is best printed in resin and the Metal case is meant for CNC. The part list lives inside the Altium schematics rather than a separate BOM file. The README does specify the key optical part: a 25.4 mm cube beam-splitter prism, about 80 yuan on Taobao, fixed to the screen with OCA adhesive rather than liquid glue, which can seep under the display. The board is built around an ESP32-PICO-D4 with an MPU6050 and a 1.3-inch 240x240 ST7789 screen. If you have never ordered SMT assembly, the small two-layer board is a good first one. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.