Lumalien
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LumaLight

Build Guide

Print, build and flash LumaLight, the free open-source proximity nightlight: five printed parts, an ESP32, a VL53L1X distance sensor and a 12-LED ring, wired on the bench before anything goes in the box.

Rev 1.0Updated October 13, 2026Build time · About an hour, plus printing
LumaLight glowing in a dark room
Controller
ESP32 dev board
Size
62 × 56 × 100 mm
Printed parts
5, no supports
Firmware
PlatformIO, MIT license

Section 01

Safety first

  • Wire with the USB cable unplugged.
  • The ring's brightness is capped in firmware (MAX_BRIGHTNESS) so it runs safely from USB power. Do not raise it without a supply that can carry the current.
  • The distance sensor is a Class 1 infrared laser device. It is eye-safe in normal use; do not stare into its window at close range.

Section 02

Meet LumaLight

LumaLight is an upright white box, 62 × 56 × 100 mm. The front carries a 46 mm frosted halo with the NeoPixel ring behind it and a small window for the distance sensor below. The back is a screwed-on panel that carries the ESP32, so the whole harness comes out with it.

LumaLight from four angles: top, front, base and back panel

Section 03

Parts and tools

Nothing ships with LumaLight, so this is your shopping list. BOM.md in the repository is the current version.

Tools you will need

  • 3D printer (designed on a Bambu Lab A1)
  • Screwdriver for M2.5 self-tapping screws
  • Glue for the diffuser and the inlays
  • A computer with PlatformIO and a USB data cable
  • Calipers, to check the sensor's hole spacing
QtyPartNotes
1ESP32 dev board (PlatformIO board esp32dev), USB-CHangs on the back panel, USB end down.
1CQRobot VL53L1X time-of-flight sensor, 23 × 28.5 mm boardWith its 6-pin JST cable.
112-LED NeoPixel ring, GRB, about 37 mm acrossSized for the Adafruit 1643 ring.
About 7Female-to-female jumper leadsSensor and ring to the ESP32 pins.
1USB-C cable and USB power adapterPower and first flash.
4M2.5 × 6 self-tapping screwESP32 top pair, sensor board
6M2.5 × 8 self-tapping screwESP32 USB-end pair, back panel to body
FilamentFor
WhiteBody and back panel
TransparentDiffuser
PurpleThe two logo inlays

Section 04

Printing the parts

Five parts plus a test coupon. No supports and no inserts. Print in this order.

  1. 1

    The sensor test coupon

    STL/test/TEST_SENSOR_POCKET.stl, front face down, about 20 minutes. Push the real sensor board in, run the two screws, look through the window, and check the cable turns under the board.

  2. 2

    The back panel

    Outer face on the bed, standoffs up. Screw the ESP32 on with every lead plugged in, and check the housings clear: from the panel's inner face the tips should reach about 25 mm.

  3. 3

    The body, the diffuser and the inlays

    The body prints front face down with the open back up, so the plate texture finishes the front. The diffuser prints flange down in transparent filament, and the bed texture frosts it. The two inlays print flat in purple.

Section 05

Wiring

FromTo ESP32
VL53L1X SDAGPIO 21
VL53L1X SCLGPIO 22
VL53L1X power3.3 V
VL53L1X groundGND
Ring data inGPIO 18
Ring power5 V
Ring groundGND

Section 06

Assembly

Everything is wired on the bench first, so the harness is live before the body is closed.

  1. 1

    Panel and harness

    Screw the ESP32 to the panel standoffs, components toward the panel and pins toward you. Feed the USB-C cable through the panel notch from outside and plug it in. Plug the sensor and ring leads onto the pins.

  2. 2

    Sensor

    Hold the board by its edges with the JST toward the front wall and the cable hanging down. Push it straight into the pocket from the back until its face sits on the seats, line up the two top holes on the pilots, and drive two M2.5 × 6. Tuck the cable under the board.

  3. 3

    Ring

    In from the front through the halo hole, wires first, LEDs facing out, until it rests on the three tabs. Turn it so the solder pads sit between the tabs.

  4. 4

    Diffuser

    Glue the diffuser into the front recess. The ring is now captured.

  5. 5

    Close the back

    Bring the panel up to the body, fold the leads into the wire bay, seat the lip and drive four M2.5 × 8 from the back. Glue the purple inlays into the top recess.

    To service it

    Four screws, and the panel comes away with the ESP32 on it and everything still plugged in.

Section 07

Flashing the firmware

git clone https://github.com/patmakesapps/LumaLight.git
cd LumaLight
pio run -t upload
pio device monitor

Build and flash over USB, then watch the serial log at 115200 baud.

To update it over Wi-Fi later, copy include/secrets.example.h to include/secrets.h and secrets.example.ini to secrets.ini, fill in your 2.4 GHz network and a flashing password, and flash once over USB. After that, pio run -e ota -t upload updates the light where it sits.

Constant in src/main.cppDefaultChange it when
CHANGE_MM150Raise it if the light turns on by itself (steam, mirrors). Lower it if it misses people.
ACTIVE_MS120000You want a longer or shorter on time.
MAX_BRIGHTNESS110Only with a power supply that can carry more current.

Something not matching up?

If a part is missing, damaged, or your kit does not match a step, stop and get in touch before continuing.

Contact supportlumalien999@gmail.com