Kernelcon 2026 – Hardware Hacking Village
Project – USB-Powered, Touch control, dimmable LED light.
Welcome to your first hardware project! This is an entry-level assembly kit for a small, USB-powered, touch-controlled LED lamp. The kit contains all the necessary components, while we provide the tools and solder you’ll need to complete it.
Most new builders finish in an hour or less. Use these instructions as your guide, but remember that we have experienced “nerds” on hand to answer questions and lend a hand whenever you need it.
A Quick Warning: Most soldering mistakes can be fixed, provided the components and circuit board aren’t damaged. If you run into trouble, just ask for help! Also, please note that the LED modules are fragile ceramic and can break easily—don’t ask how we know.
Follow these steps, or feel free to freestyle—it’s your project, so have fun with it.
Part 1: Know Your Components
Resistors There are three different resistance values. They look identical, so rely on the color-coded bands. Since these colors can be tough to distinguish under workshop lighting, use a multimeter to verify the values. Think of it as a mandatory learning opportunity!
- (3) 100 ohms: Brown-Black-Black-Black-Brown (or similar)
- (2) 1K (1,000) ohms: Brown-Black-Black-Brown-Brown (or similar)
- (1) 47K (47,000) ohms: Yellow-Violet-Black-Red-Brown (or similar)
- Note: Resistors are non-polarized, meaning they can be installed in either orientation.
Capacitors This kit uses both non-polarized (ceramic) and polarized (electrolytic) capacitors.
- Ceramic (Non-polarized): These look like tiny tan disks and can be installed in either direction.
- (2) 100nF: Marked “104”
- Electrolytic (Polarized): These are dark cylinders. They must be oriented correctly. The lead closest to the “-” stripe is the negative lead; the other is positive. The board will have “+” and “-” markings to guide you.
- (2) 47µF: Marked “47µF”
Transistor This component acts as an electronic switch. It is polarized and has three leads: collector, emitter, and base. Match the flat side of the component body to the flat-side diagram on the circuit board.
- (1) SS8050
Integrated Circuit (IC) The IC is the “brain” of the project. It senses your touch and controls the dimming. ICs are polarized; look for a tiny dot or notch on the top of the chip that matches the notch on the circuit board’s IC footprint.
- (1) SGL822W
LEDs These produce a warm white light. They are polarized: the positive end (short tab) must connect to the “+” pad, and the negative end (long tab) must connect to the “-” pad.
- (3) LEDs (a spare is included).
PCB This is a 2-sided board where all the parts are soldered
Part 2: Assembly
Step 1: Sort Your Parts Lay everything out and verify you have all the parts listed above.
Step 2: The Build
- Prep the Board: Attach the standoffs to the “component” side of the board (the side without the fingerprint logo). This keeps the board stable while you solder.
- Resistors: Start with the resistors, as they sit lowest to the board. Bend the leads at a 90-degree angle, insert them into the correct holes, and bend the leads outward on the back to hold them in place. Solder them and clip the excess wire length.
- Pro-tip: Hold the lead with your finger while clipping to prevent it from flying across the room!
- Capacitors: Install the ceramic capacitors first (no polarity). Then, install the electrolytic capacitors, ensuring the negative lead (marked with the stripe) goes into the hole marked “-“.
- Transistor: Gently spread the leads to fit the holes. Ensure the flat side of the transistor matches the board marking. Solder in place.
- Integrated Circuit: Apply a tiny dab of flux to each pad. Align the IC (dimpled corner to notched marking). Solder one corner pin first to “tack” it down. If it’s crooked, heat the pin and nudge it into place. Once aligned, solder the remaining pins.
- LEDs: Handle with extreme care. Place them into the rectangular pads, matching the “+” and “-” markings. Solder one side, then the other.
- Power: Find the “GND” and “+5V” pads. Strip a tiny bit of insulation from your USB-C connector leads and “tin” them (apply a little solder). Slip them through the PCB holes, solder the black wire to “GND” and the red wire to “+5V”.
Step 3: Test
Plug a USB-C cable into a power bank or port. Tap the fingerprint sensor to toggle the light. Press and hold to dim the brightness.
If it doesn’t work: Disconnect the power immediately! Check your solder joints for bridges (accidental connections) or cold joints (dull/blobby solder). Check that your polarized parts (electrolytic caps, LEDs, IC, transistor) are facing the correct way. If you’re still stuck, grab a nerd!
Final Note
Below is a diagram of the LED light circuit. For fun, you can look for the parts you installed and see if you can figure out some of the workings of the parts.
