LuxLibre

Aurora++ v0.5 — Build guide from zero

This guide takes you from “I have never ordered a circuit board” to a working flashlight in your hand. You do not need to know electronics or programming. You need patience, a soldering iron and a computer with the Chrome or Edge browser. Read the whole guide once before you order anything.

Aurora++ v0.5

The finished light: 94.4 × 20 × 16 mm, black anodised aluminium, USB-C charging, a white LED in front, a small green laser below it, and Bluetooth for the phone app.

0. What you are building


Size	94.4 × 20 × 16 mm, about 50 g with cells
Main light	Luminus SST-20 LED, 3 mA (moonlight) to 2.2 A (turbo, short bursts)
Laser	green 520 nm module, Class 2 (≤ 1 mW), with a hardware safety switch
Battery	two LP601646 lithium-polymer cells in parallel, about 800 mAh
Charging	USB-C, about 300 mA, status shown by a small RGB LED through the lid
Brain	ESP32-C3 module with Bluetooth Low Energy
Phone app	a web page — no app store, works in Chrome/Edge (Android, Windows, Mac, Linux)
Firmware updates	from a web page over the same USB-C cable — no programmer needed

How it is made:

The circuit board (24 × 16.5 mm, 4 copper layers) is made and fitted with all its small parts by JLCPCB. You only solder a few wires by hand.
The aluminium body (two parts: tray and lid) is machined and anodised by JLCCNC.
Four small plastic parts are 3D-printed by JLC3DP as one “print kit”.
The LED board, the laser, the cells, the window and the screws are bought ready-made (for example on AliExpress).

1. Before you spend money

Cost. The workbook Aurora_Parts_List_v0.5.xlsx lists every part and every fee. The short version (prices checked 2026-10-14, delivery to Lithuania):

	one light	per light when you build five
Everything, including shipping, VAT and set-up fees	about 530 USD (473 EUR)	about 196 USD (175 EUR)
Tools you may not have yet (one-time)	about 128 USD

One light is expensive because the fixed costs (assembly set-up, stencils, three parcels from JLC, several AliExpress parcels) are paid once whatever the quantity. JLCPCB makes at least 5 boards and assembles at least 2. Building with friends brings the price down a lot.

Time and the order of the orders. Building takes one afternoon; the waiting takes longer. Order in this sequence (the workbook’s sheet Ordering checklist has the same steps):

Day 1: order the bought parts (section 6) and the circuit boards (section 3).
When the cells, the LED board and the laser have arrived (2–5 weeks from AliExpress): measure them (section 8). They must match the specification — the body is made for them.
Then order the aluminium body (section 4) and the print kit (section 5); about 10 days.

At every checkout choose shipping with taxes and duties paid (DDP / “tax included”) — the cost figures above assume it.

Skills. Soldering wires to pads (practise on scrap first), using a small screwdriver, following instructions exactly. Nothing else.

Safety — read this.

Lithium cells can burn if they are short-circuited, punctured, bent or charged wrongly. Never let the red and black wires of a cell touch each other. Never solder on the cell itself — only on the wires. Keep a metal box or a sand-filled pot nearby while you work.
The laser is a real laser. Class 2 is safe for an accidental glance, but never look into it or point it at people, animals, cars or aircraft. Wear 520 nm laser safety glasses while testing. Buy only a module whose seller states Class 2 / ≤ 1 mW.
The LED gets hot in turbo. The firmware limits the temperature, but do not cover the light with your hand for minutes in turbo.

2. The files

Everything you upload is ready in the folder order_files/ of the package, one subfolder per shop — you never have to look for a file anywhere else:

File	What it is	Who gets it
`order_files/1_JLCPCB/Aurora_main_gerbers.zip`	the circuit board drawings	JLCPCB (PCB)
`order_files/1_JLCPCB/BOM_JLCPCB.csv`	list of parts to mount	JLCPCB (assembly)
`order_files/1_JLCPCB/CPL_JLCPCB.csv`	where each part goes	JLCPCB (assembly)
`order_files/2_JLCCNC/Aurora_tray.step` + `Aurora_tray.pdf`	aluminium body + its drawing	JLCCNC
`order_files/2_JLCCNC/Aurora_lid.step` + `Aurora_lid.pdf`	aluminium lid + its drawing	JLCCNC
`order_files/2_JLCCNC/Aurora_marking_class2.dxf`	optional laser marking	JLCCNC
`order_files/3_JLC3DP/Aurora_print_kit.stl`	the four plastic parts on one sprue	JLC3DP
`app/aurora-flasher.html`	the firmware installer (open in Chrome/Edge)	you
`app/aurora-app.html`	the phone/computer app (open in Chrome/Edge)	you
`Aurora_Parts_List_v0.5.xlsx`	every part, price, link and fee	you

(The same files, with all the source data behind them, are also in production/ and cad/.)

3. Order 1 — circuit boards with parts mounted (JLCPCB)

Make an account at jlcpcb.com and log in.
Click Order now (or “Instant quote”) and Add gerber file. Choose order_files/1_JLCPCB/Aurora_main_gerbers.zip. Wait until the picture of the board appears (24.0 × 16.5 mm should be detected automatically).

Set these options (leave everything not listed at its default):

Option	Choose
Base material	FR-4
Layers	4
PCB qty	5 (the minimum)
PCB thickness	0.8 mm
PCB color	green (cheapest; others are fine)
Surface finish	ENIG (flat gold pads — needed for the Bluetooth module)
Outer / inner copper	1 oz / 0.5 oz
Via covering	Tented
Min via hole size/diameter	the value JLCPCB detects (0.2 mm hole, 0.45 mm via: no surcharge)
Remove order number	No (the default) — JLCPCB prints a small number on a free spot; it is hidden in the body

Scroll down and switch PCB Assembly on:

Option	Choose
PCBA type	Standard (parts on both sides need Standard)
Assembly side	Both sides
PCBA qty	2 (the minimum) — or as many lights as you build, if more
Tooling holes	Added by JLCPCB
Confirm parts placement	Yes (an engineer checks the orientation of every part — recommended)

Click Next, then upload BOM = order_files/1_JLCPCB/BOM_JLCPCB.csv and CPL = order_files/1_JLCPCB/CPL_JLCPCB.csv. Click Process BOM & CPL.
The parts list appears. Every line should show a matched part with stock. If a part is out of stock, the workbook (sheet Main PCB BOM) names the alternative — the only one you are likely to need is the Bluetooth module: C2838502 (ESP32-C3-MINI-1-N4) can be replaced by C41349510 (ESP32-C3-MINI-1-H4X), same footprint, same firmware. (A few small parts had low retail stock on 2026-10-14 — C15850, C15195, C1525, C11702, C485117; JLCPCB’s assembly stock is separate and usually fine. The workbook’s stock notes list a substitute.)
Placement preview. JLCPCB shows the board with every part drawn on it. For each chip, the small dot or line that marks pin 1 must sit on the pin-1 mark of the board. If one is turned, select it and use Rotate. Look closest at the parts whose drawing in JLCPCB’s library is often turned against KiCad’s: the Bluetooth module U4, the small chips U1, U2, U3, U5, the transistors Q1, Q2, Q4, Q5, the USB-C socket J1 and the tiny RGB LED LED3. Do not worry if you are unsure: with “Confirm parts placement” an engineer checks it and sends you a picture before production.
Save to cart, pay. The board order (5 boards, 2 of them assembled, all parts included) costs about 170 USD before shipping and VAT (the workbook, sheet JLCPCB order, shows every line). Choose a shipping method with taxes paid (DDP).

Why the gold surface (ENIG)? The Bluetooth module sits on a big flat ground pad under its belly. Tin (HASL) surfaces are bumpy and the module can end up crooked. ENIG costs a few dollars more and avoids that.

4. Order 2 — the aluminium body (JLCCNC)

Go to jlccnc.com, log in with the same account, Instant quote → CNC machining.
Upload order_files/2_JLCCNC/Aurora_tray.step and Aurora_tray.pdf from the same folder — JLCCNC matches the drawing to the 3D file by its name, which is why both are called Aurora_tray (the drawing carries the threads and tolerances JLCCNC needs). Do the same for the lid: Aurora_lid.step + Aurora_lid.pdf.

For both parts choose:

Option	Choose
Material	Aluminum 6061-T6
Surface finish	Bead blasting + anodizing, black
Tolerance	ISO 2768-m (standard)
Threads	yes — write in the remark: “4 × M1.6×0.35 in the tray, 1 × M2×0.4, see drawing; tapped before anodising, screws must fit after finishing (drawing note 3)”
Quantity	one of each per light (+1 spare tray if you want a safety margin)

Optional: laser marking with order_files/2_JLCCNC/Aurora_marking_class2.dxf on the bottom face (the laser warning text). Only if your laser module really is Class 2.
JLCCNC answers with a price within a day. If they say M1.6 threads are not possible, accept plain holes: the drawing gives the tap-drill size, and you cut the thread yourself with an M1.6 hand tap (about 5 USD).

5. Order 3 — the plastic parts (JLC3DP)

jlc3dp.com → Instant quote, upload order_files/3_JLC3DP/Aurora_print_kit.stl. (Only if your laser module is 4.5 mm instead of 6 mm thick, also upload Aurora_laser_sleeve.stl.)
Material: SLA resin, 8001 (translucent). The kit contains the RF window (lets the Bluetooth signal and the status LED through the aluminium lid), the button cap, the LED spacer ring and the antenna spacer, joined by thin rods. You cut them apart with side cutters at home.
Quantity: one kit per light (they are cheap — order one spare kit).

6. Order 4 — parts you buy ready-made

Search these on AliExpress (or any electronics shop). The workbook has a link example and the typical price for each. Order them first (section 1) and measure what you receive before you order the aluminium body.

Part	Exact specification	Quantity per light
LiPo cells	LP601646 (6.0 × 16 × 46 mm), 3.7 V, about 400 mAh, with protection board and wire leads, rated for at least 2 C continuous (0.8 A per cell; 3 C if you want the Extreme profile); the whole cell including its protection board must fit 6.0 × 16 × 47 mm	2 (+1 spare)
LED board	Luminus SST-20 (white, 5000–6500 K) on a 10 mm round copper DTP board, 1.6 mm thick	1
Laser module	520 nm green, 6 × 12 mm body, with a built-in constant-power (APC) driver for a 3.0–4.2 V supply (the board gives it the cell voltage), Class 2 (≤ 1 mW), with wires	1
Window	glass or PMMA disc 10 mm × 1.0 mm (AR-coated “flashlight lens” is best)	1
Lid screws	M1.6 × 4 mm countersunk, stainless (A2)	4 (+4 spare)
Laser set screw	M2 × 2 mm set screw, cup point (M2 × 2.5 also fits; longer ones stick out of the bottom)	1
Wire	28 AWG PTFE, red and black (usually sold as 5 m rolls; one light needs about 0.3 m)	—
Thermal paste or 0.15 mm thermal tape	for the LED board	a little
Kapton tape, thin double-sided foam tape	insulation, cells	a little
Clear 5-minute epoxy or UV resin	RF window and front window	a little
Split ring or lanyard	through the tail slot	1

7. Tools

Tool	Why
Soldering iron with a fine tip (a temperature-controlled one, e.g. Pinecil or TS101)	the wires
Desoldering braid (wick)	to remove solder if a joint goes wrong
Digital caliper	measure the cells, the LED board and the laser before you order the body
Solder 0.5 mm with flux core, plus a flux pen	clean joints on small pads
Fine tweezers, side cutters, wire stripper (or a sharp knife)	wires, print kit
Small screwdriver for M1.6 countersunk screws (check the head type you bought)	lid
0.9 mm hex key (for the M2 set screw)	laser
Multimeter	check cell voltage and polarity
Laser safety glasses for 520 nm	laser test
USB-C cable that carries data	firmware — many cheap cables only charge
Computer with Chrome or Edge (Windows, macOS, Linux or ChromeOS)	firmware installer
Isopropyl alcohol, cotton swabs	cleaning flux

8. When the parcels arrive — check

Boards: look at both sides under good light (a phone camera zoom works). No part missing, no part crooked, no solder bridges between pins of the Bluetooth module.
Body: the PCB must drop into the tray (section 12.8 shows how) and the lid must close flat. The four lid threads must accept a screw by hand.
Cells: measure each with the multimeter: 3.6–4.2 V is normal for new cells. Size with the protection board: at most 6.0 × 16 × 47 mm. The two cells should be within 0.1 V of each other (0.05 V is ideal) before you connect them.
LED board: 10.0 mm diameter, 1.6 mm thick, the “+” and “−” marks are readable.
Laser: 6.0 mm diameter, ≤ 12 mm long. Red wire = +, black wire = −.

The pads you will solder. Front end = the end with the LED pad J3 (the head of the light); rear end = the end with the cell pads J2. Keep this picture next to you:

Wiring pads

The two sides of the board. Red pads are +, dark blue pads are −. The small “+” and “−” printed on the board are tiny and partly covered by solder mask — trust the picture.

9. Step 1 — Prepare the cells

The flashlight takes its power from the cells — also while you install the firmware. So the cells come first.

Check polarity. Red = +, black = −. Confirm with the multimeter (red probe on the red wire: the reading must be positive).
Match the voltages. Both cells within 0.1 V. If they differ more: solder only the fuller cell (steps 3–6), install the firmware (section 10) and charge it until the LED is steady green; unsolder it, do the same with the other cell; then both are full and equal.
Check the board for a short. Set the multimeter to the beep (continuity) setting and touch the two J2 pads (see the picture above): it must not beep. If it beeps, stop and look at the board under a magnifier — do not connect the cells.
Shorten the wires to about 40 mm (cut one wire at a time — cutting both at once with the same cutter short-circuits the cell!). Strip 2 mm, twist, tin with solder.
Twist the two red wires together and the two black wires together (still one at a time).
Solder to the board — the cell pads J2 are the two big pads near the rear end on the bottom side (the side with the USB-C socket). J2 + (red wires) is the pad nearer the edge with the slide switch S2; J2 − (black wires) is the pad nearer the middle of the board (see the picture). Put a little flux on the pad, hold the tinned wire on it, touch with the iron for 2–3 seconds. Red first, then black.
The board is now powered. Nothing lights up yet — the firmware is not installed. Lay the board and cells on a non-metal surface.

If anything gets hot, smells or smokes: pull the cells away with pliers by the wire, put them in the metal box. A reversed cell destroys the board — that is why step 1 matters.

10. Step 2 — Install the firmware (no experience needed)

The firmware is the program that runs in the flashlight. You install it from a web page, through the flashlight’s own USB-C socket. Nothing to download, nothing to install on your computer.

You need: the board with the cells soldered on (step 1), a USB-C cable that carries data, and a computer with Google Chrome or Microsoft Edge. (Firefox and Safari cannot do this, and phones cannot flash.)

1. Open the installer. Open app/aurora-flasher.html from the package in Chrome or Edge (double-click the file; if it opens in another browser, right-click → Open with → Chrome). If someone has put the package on a website (see docs/web_apps.md), you can open the same page from there instead.

2. Plug in. Connect the flashlight’s USB-C socket to the computer. The status LED starts breathing red slowly (charging) — if the firmware was not installed yet, it may stay dark; that is normal.

3. Connect. Click Connect. A small browser window lists the serial ports. Choose:

on Windows: “USB Serial Device (COM3)” (the number can differ),
on macOS: “USB JTAG/serial debug unit” (cu.usbmodem…),
on Linux/ChromeOS: “USB JTAG/serial debug unit” (ttyACM0).

and click Connect in that window. The page says “Flashlight found (ESP32-C3, 4MB memory)”.

Installer, step 3

4. Install. Click Install firmware. A progress bar runs for about one minute. Do not unplug while it runs.

5. Done. The page says the installation is complete. Unplug the cable and plug it in again. The status LED breathes red (charging) or shows steady green (full).

That’s it. To update the firmware later, do exactly the same with a newer installer page. Installing resets the saved settings (your custom profile) to the factory defaults.

If “Connect” shows no port

The cable. Most failures are charge-only cables. Try another cable — one that can move files to a phone is a data cable.
Another USB port, directly on the computer (not through a hub).
Windows 7/8 have no built-in driver for this USB serial port; use Windows 10/11.
Linux: your user must be allowed to use serial ports: sudo usermod -a -G dialout $USER, then log out and in again.

If the port appears but connecting or installing fails

Force the chip into its built-in installation mode (it cannot be broken this way):

Unplug the USB cable.
Press and hold the flashlight button (the side button S1 — on the bare board it is the small black switch on the bottom side, at the edge next to the USB-C socket).
While holding it, plug the USB cable in. Keep holding for about a second, then release.
Click Connect again and choose the port. Then Install firmware.
When it is done, unplug and replug (or press the button once).

Why this works: plugging in USB restarts the chip (a small circuit on the board does that), and a chip that starts with the button pressed waits for new firmware instead of running the old one.

What happens inside (for the curious)

The ESP32-C3 has a USB port built in. The installer page uses your browser’s Web Serial feature and the open-source esptool-js to write one file (aurora-fw-v0.5.0-merged.bin, 419,136 bytes — bootloader, partition table and program) to address 0 of the module’s 4 MB flash memory. The page checks the file’s fingerprint (SHA-256) before writing.

11. Step 3 — Test on the bench (lid open, nothing in the body yet)

Bluetooth. On a computer with Bluetooth, open app/aurora-app.html in Chrome or Edge (a phone needs the app from a web address — see section 14). Press the flashlight button three times quickly: the RGB LED blinks blue twice — Bluetooth is on for 2 minutes. In the app, click Connect, choose Aurora-XXXX. You see the battery percentage, the voltage and the temperature.
LED (optional, quick). Solder the LED board temporarily with two wires (LED+ to the top pad J3, LED− to the bottom pad J3, same spot on both sides of the board). Click the button once: low light. Do not run high levels on the bench — without the aluminium body the LED board has nothing to shed heat into. Unsolder again.
Charging. Plug USB in: the RGB LED breathes red, later steady green.

12. Step 4 — Assemble

Work on a clean towel. The order matters, because some joints cannot be reached later.

12.0 Make it safe first. The cells are connected, so the board is live. Push the knob of the slide switch S2 towards the front (LED) end — SAFE — and lock the light with four quick clicks (red ×3). It stays locked until section 13.

Exploded view

Exploded view: window, spacer ring and LED board go into the head from the front; the laser below them; the PCB with the cells drops into the tray; the antenna spacer sits behind the PCB; the lid with its translucent RF window closes everything with four screws.

12.1 Cut the print kit. Cut the four parts off their rods with side cutters, close to the part, and trim the stubs with a knife: RF window (the flat stepped plate), button cap (the tiny plunger), spacer ring (the ring) and antenna spacer (the U-shaped block).

12.2 LED board. Solder a red wire (60 mm) to the + pad and a black wire (60 mm) to the − pad of the LED board, on the LED side, with the wires pointing away from the board’s centre. Hold the board so that + is at 12 o’clock (top, lid side) and − at 6 o’clock.

12.3 Into the head. From the front of the body, push the red wire into the upper groove of the big bore and on through the upper hole into the inside of the body; the black wire through the lower groove and hole. Put a thin layer of thermal paste (or the thermal tape) on the back of the LED board and push the board to the bottom of the bore, wires pulled gently from inside.

12.4 Spacer ring and window. Insert the spacer ring (its notches go over the two solder joints), then the glass window. Fix the window with three tiny dots of clear epoxy or UV resin at its edge. Keep the glass clean.

12.5 Laser. Push the module into the small bore below the LED from the front, wires first, until its front sits 0.2–0.3 mm behind the front face (no thermal paste needed — a Class 2 module makes almost no heat). Tighten the M2 × 2 set screw from the bottom of the body with the 0.9 mm hex key — gently, the module body is soft brass.

12.6 Button cap. From inside, push the button cap into the small rectangular hole in the control-side wall (flange inside).

12.7 Wires to the board (bottom side first).

Laser: J5 is the pair of pads side by side on the bottom side (see the picture in section 8): red to the pad nearer the front (LED) end (+), black to the other one (−). Shorten the wires so that about 15 mm of slack remains.
LED black (−): to the bottom pad of J3 (front end of the board).
LED red (+): to the top pad of J3 (same position, other side) — you can also do this one after the board is in, the top side stays reachable.

12.8 Board in. The slide switch S2 sticks out of the board edge on the side opposite the USB-C socket.

Tilt the board a little (about 5°) with the S2 side low, front end towards the head.
Push the front edge under the head step, guide the S2 knob into its slot in the side wall.
Lower the USB-C side: the USB-C socket, the button switch (behind the cap) and the edge of the board drop into their openings and onto the ledges.
Press the button from outside: it must click (the RGB LED gives a short red flash — the light is still locked, as it should be).

12.9 Antenna spacer and cells. Push the U-shaped antenna spacer in behind the board: the module’s antenna (it sticks out of the board’s rear edge) sits in the U, the cell wires pass through the notch. Put a strip of Kapton over each cell’s protection board. Lay both cells into the bay behind the spacer, flat, one on top of the other (the bay is two cells high), the end with the protection board and the wires towards the PCB, and put a strip of foam tape on top so that the lid holds them without rattling.

12.10 Lid. Glue the RF window into the lid from inside (epoxy on the flange, not on the top face) and let it cure. Put the lid on and fasten the four M1.6 × 4 screws — snug only, the threads are in aluminium and strip easily.

12.11 Thread a split ring or a lanyard through the slot in the tail.

13. Step 5 — First use

One click: on (Low the first time). One click again: off.
Hold while on: steps Low → Medium → High.
Double click: turbo for 45–60 s, then it steps down by itself.
Laser: with the light off, click, then click-and-hold: the laser is on while you hold. The small slide switch S2 in the side wall must be armed — knob pushed towards the tail (away from the LED). With the knob towards the LED the laser cannot come on, whatever the software does: the switch cuts the laser’s control line in hardware. Check it once, with the safety glasses on and the light pointed at a wall (unlock first: four clicks, green ×3): knob towards the LED → the gesture must do nothing; knob towards the tail → the laser comes on. If the laser comes on with the knob towards the LED, your switch works the other way round: then towards the tail is SAFE — mark the safe side on the body with a dot of paint and remember it.
Triple click (off): Bluetooth for 2 minutes. Four clicks: lockout (red ×3); four clicks again unlocks (green ×3).

The complete button table, the RGB LED colours and the protection behaviour are in docs/firmware.md, chapter 2 (the user manual).

14. The app

On a computer (Windows, Mac, Linux, ChromeOS with Bluetooth): open app/aurora-app.html in Chrome or Edge. On a phone the page must come from a web address (https): put the app folder on GitHub Pages once — free, about 10 minutes, step by step in docs/web_apps.md, section 4 — and open that address in Chrome on Android or in the free Bluefy browser on an iPhone. Bluetooth is only on while the light is on, 2 minutes after it was switched off, after a triple click, or while USB is connected — so switch it on (or triple-click) before you tap Connect.

App

Battery, voltage, temperature, runtime left at the top.
On/Off and the levels — the button on the light always wins: for 3 s after you press it, the app cannot switch or dim the light (“the button has priority”).
Profiles: Extreme (maximum light for short bursts — 2.2 A turbo for 45 s), Balanced (default), Endurance (longest battery life, the LED never runs above 300 mA), Custom (your own: every level, the turbo current and time, the temperature limit, the battery limits — then Save to flashlight).
Demo mode shows the app without a flashlight.

15. Troubleshooting

What you see	What to do
Nothing at all when you click	Charge it (USB).
A short red flash when you click	Locked: four clicks unlock it (green ×3).
Five fast red blinks	Battery empty: charge it.
One red blink when you ask for turbo	Too hot — turbo is refused near the temperature limit. Wait.
Light gets dimmer by itself	Normal: turbo time over, or temperature / battery protection.
App: “the button has priority”	Wait 3 seconds after pressing the button, then try again.
App finds no flashlight	Bluetooth is off to save power: triple-click the light, then Connect.
Installer: no port	Data cable, other USB port (section 10).
Installer: connection fails	Hold the button while plugging in (section 10).
Red LED flickers briefly when it starts	Normal (the boot message runs over that pin).
Laser does not come on	S2 must be armed (knob towards the tail); the gesture is click + click-and-hold from off; it stops above 60 °C, below 3.2 V and after 60 s.
USB does not charge	The charger pauses above 45 °C and below 0 °C, and while the LED runs above 500 mA.

16. Where to read more

docs/firmware.md — how the firmware works, the user manual, the bench test plan.
docs/ble_protocol.md — the Bluetooth protocol (for anyone who wants to write their own app).
docs/web_apps.md — the app and the installer, and how to put them on GitHub Pages.
docs/bom_notes.md — where every price in the workbook comes from.
docs/ch12_v0.5_bluetooth_redesign.md — the design story of v0.5 (why every decision was made).

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