4 layers88 × 58 mm
2 layers67.3 × 53.3 mm
SkyChain
RockingRidz/SkyChainSkyChain is a compact PCB keychain that tracks live flights overhead. Powered by an ESP32 and a 0.96" OLED screen, it uses Wi-Fi to fetch flight numbers, altitude, and routes via the OpenSky API. The board features custom I2C routing, USB-C charging via TP4056, a 3.3V regulator, tactile buttons, and a keyring hole.
- Size
- 67.3 × 53.3 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 22
- Nets
- 47
- Pads
- 122
- Tracks, vias
- 418, 45
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 5 Oct 2026
- Updated
- 27 Oct 2026
Overview
SkyChain is an open-source printed circuit board by RockingRidz, from the RockingRidz/SkyChain repository on GitHub. It is a 2-layer board of 67.3 × 53.3 mm with 22 parts on 47 nets, routed with 418 tracks and 45 vias.
It is built around the ESP32-C3-DEVKITM-1, AMS1117-3.3 and TP4056-42-ESOP8. Its parts include 7 resistors, 4 capacitors, 3 ICs, 3 connectors and 3 switches. It belongs with the lEDs and displays boards and the ESP32 and RISC-V boards of this library.
Main components
3
ESP32-C3-DEVKITM-1
-- WiFi Modules ROHSEspressif SystemsWiFi Modules
AMS1117-3.3
SOT-223-40℃~+125℃ 0.003%Vout 1 1.1V@(800mA) 15V 1A 3.3V 5mA 72dB@(120Hz) Fixed Over Current Protection、Short Circuit Protection、Thermal shutdown Positive SOT-223 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSAdvanced Monolithic SystemsVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
TP4056-42-ESOP8
ESOP-8-40℃~+85℃ 1 1A 2uA 4.2V 4V~8V Charging IC Lithium Battery Support ESOP-8 Battery Management ROHSTOPPOWERBattery Management
README
README.mdSkyChain
SkyChain is a compact, wearable smart keychain designed to clip onto your belt, fit in your pocket, or go anywhere with you. Whenever you spot a plane flying overhead or want to check real-time flight telemetry, SkyChain delivers live aircraft tracking data directly to your OLED screen.
Bill of Materials (BOM)
| Part | Description | Qty | Price |
|---|---|---|---|
| ESP32-C3-DevKitM-1 | Microcontroller (U3) | 1 | $10.00 |
| TP4056-42-ESOP8 | Battery Charger IC (U1) | 1 | $2.00 |
| AMS1117-3.3 | LDO Voltage Regulator (U2) | 1 | $1.50 |
| USB_C_Receptacle_USB2.0_16P | USB Interface (J1) | 1 | $2.00 |
| Conn_01x04_Socket | Display Connector (J3) | 1 | $1.00 |
| Conn_01x02_Socket | Battery Connector (J2) | 1 | $1.00 |
| SW_Push | Buttons (SW1-SW3) | 3 | $0.50 |
| Piezo Buzzer | Audio Buzzer (BZ1) | 1 | $1.50 |
| NPN Transistor | S8050 Transistor (Q1) | 1 | $1.00 |
| SMD Resistors | Resistors (R1-R7) | 1 | $4.00 |
| SMD Capacitors | Capacitors (C1-C4) | 1 | $3.00 |
| 3D Printed / Acrylic | Enclosure & Window | 1 | $1.50 |
| Total | $30.00 |
Overview & How It Works
SkyChain fetches live overhead tracking data via the OpenSky Network API to give you real-time details about aircraft above you:
- Flight Callsign & Identification
- Country of Origin
- Altitude & Flight Height
Every time SkyChain queries the OpenSky API or receives updated telemetry, it updates its onboard display to show current flight tracking data.
Core Features
- Real-Time Flight Tracking: Connects via Wi-Fi to the OpenSky REST API for live aircraft callsigns, countries, and altitude metrics.
- Interactive Multi-Function UI: Controlled via a 2-button tactile layout supporting single clicks, double-clicks, and long-presses to navigate menus.
- Visual Display: Integrated high-contrast 128x64 SSD1306 OLED screen for displaying clear flight stats and system menus.
- Autonomous Battery Management: Onboard USB-C charging and LiPo battery regulation for untethered daily wear.
- Compact Keychain Form Factor: Portable, lightweight hardware layout designed for everyday carry with an integrated spline window and acrylic viewing pane.
Custom Hardware Design
Designing and routing the printed circuit board and 3D-printed enclosure has been an exciting hardware challenge:
- Microcontroller Core: ESP32 module managing Wi-Fi requests, display driving, and button debounce logic.
- Power System: Lithium battery charging paired with a low-dropout regulator and USB-C power delivery.
- Enclosure Geometry: Custom CAD model featuring a 2.0 mm wall enclosure, reinforced keychain mount, and a recessed internal ledge for a flush-fit acrylic window.
- Optimized Passives: SMD passive array for power decoupling, USB pull-downs, and robust circuit stability.
- THIS WAS MY 3RD PCB DESIGN AND PROLLY THE MOST COMPLEX IVE MADE!!
Parts
22| Qty | Value | Footprint | References |
|---|---|---|---|
| 3 | SW_Push | Button_Switch_SMD:SW_SPST_PTS645Sx43SMTR92 | SW1, SW2, SW3 |
| 2 | 100k | Resistor_SMD:R_0805_2012Metric | R6, R7 |
| 2 | 100nF | Capacitor_SMD:C_0805_2012Metric | C2, C4 |
| 2 | 10uF | Capacitor_SMD:C_0805_2012Metric | C1, C3 |
| 2 | 1k | Resistor_SMD:R_0805_2012Metric | R4, R5 |
| 2 | 5.1k | Resistor_SMD:R_0805_2012Metric | R1, R2 |
| 1 | 1.2k | Resistor_SMD:R_0805_2012Metric | R3 |
| 1 | AMS1117-3.3 | Package_TO_SOT_SMD:SOT-223-3_TabPin2 | U2 |
| 1 | Buzzer | Buzzer_Beeper:Buzzer_12x9.5RM7.6 | BZ1 |
| 1 | Conn_01x02_Socket | Connector_JST:JST_PH_S2B-PH-K_1x02_P2.00mm_Horizontal | J2 |
| 1 | Conn_01x04_Socket | Connector:FanPinHeader_1x04_P2.54mm_Vertical | J3 |
| 1 | ESP32-C3-DevKitM-1 | RF_Module:ESP32-C3-DevKitM-1 | U3 |
| 1 | NPN | Package_TO_SOT_SMD:SOT-23 | Q1 |
| 1 | TP4056-42-ESOP8 | Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.41x3.3mm_ThermalVias | U1 |
| 1 | USB_C_Receptacle_USB2.0_16P | Connector_USB:USB_C_Receptacle_HRO_TYPE-C-31-M-12 | J1 |
Questions
How big is the SkyChain PCB?
It measures 67.3 × 53.3 mm and has 2 copper layers, 1.6 mm thick.
What parts does the SkyChain use?
22 parts, built around the ESP32-C3-DEVKITM-1, AMS1117-3.3 and TP4056-42-ESOP8. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the SkyChain KiCad files?
From the RockingRidz/SkyChain repository on GitHub, at the commit this page was made from: the board is pcb/SkyChain.kicad_pcb and its schematic pcb/SkyChain.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the SkyChain design in my own project?
Its repository states no licence, so its author keeps all rights: ask RockingRidz before reusing the design.
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