Shine

Shine On V1

A simple 2-layer LED indicator board designed to plug into a Raspberry Pi 4 GPIO header. Built as a hands-on exercise in schematic capture, PCB layout, component selection, DFM, and hand soldering.

Designed in: KiCad
Fabricated by: OSHPark ($5.00 for 3 boards)
Components sourced from: DigiKey
Assembly: Hand soldered by designer
Board size: 25.4 x 25.4 mm (1.00 x 1.00 in), 2-layer

Schematic

Both LEDs are driven in a simple series configuration:

• D1: +3.3V -> D1 (LED 1206) -> R1 (200 ohm) -> GND
• D2: GPIO2 -> D2 (LED 1206) -> R2 (200 ohm) -> GND

Current limiting resistors R1 and R2 are 200 ohm, 1/4 W rated, 1206 package. At 3.3V with a typical LED forward voltage of ~2.0V:

I = (3.3V - 2.0V) / 200 ohm = ~6.5 mA

Well within GPIO drive capability (~16 mA max) and LED ratings. Power dissipation per resistor ~8.5 mW, well under the 250 mW rating.

The 10-pin dual-row header (J1) connects directly to the Raspberry Pi 4 GPIO header, exposing +3.3V, GPIO2, and GND.

PCB Layout

Design Decisions

• 1206 SMD footprints chosen for all passives and LEDs to enable reliable hand soldering -- larger pads reduce the risk of tombstoning and bridging compared to 0402/0603.
• No copper pours -- basic 2-layer board with point-to-point trace routing. Unnecessary complexity avoided for a low-frequency, low-power design.
• Silkscreen labels (PWR, GPIO2) placed near each LED for immediate functional identification without referring to a schematic.
• Board name and revision block included in silkscreen per professional documentation practice.
• Chamfered board corners on the edge cuts layer.

Bill of Materials

Components ordered from DigiKey (Order #99956045), shipped 6/22/2026.

Footprints used:

• D1, D2: LED_SMD:LED_1206_3216Metric_Pad1.42
• R1, R2: Resistor_SMD:R_1206_3216Metric_Pad1.42
• J1: Connector_PinHeader_2.54mm:PinHeader_2x05_P2.54mm_Vertical

Fabrication

Fabricator: OSHPark
Stack-up: 2-layer, 1 oz copper, purple solder mask, ENIG finish
Board cost: $5.00 (includes 3 copies)
Uploaded: June 22, 2026

OSHPark renders:

Lessons Learned

• OSHPark's 1" x 1" minimum makes this an ideal low-cost prototype vehicle for simple indicator/breakout boards.
• 1206 is noticeably easier to hand solder than 0603 -- pads are large enough to tin individually and place with tweezers without a hot plate.
• Silkscreen functional labels (not just reference designators) significantly improve board usability without added cost.
• Sourcing resistors in a strip of 50 and LEDs in a strip of 10 keeps unit cost negligible while building personal component inventory.

Repository Structure

shine-on-v1/
├── kicad/
├── gerbers/
├── images/
├── bom/
└── README.md

Author

David Valle
Electrical Engineering, Stevens Institute of Technology
REV A -- June 20, 2026