PocketStockV2

📈 PocketStock

A palm-sized, WiFi-connected stock ticker built from under $10 of parts. Live prices, sparkline charts, and a market clock — on your desk, off your phone.

ESP32-C3 · SSD1306 OLED · 3 buttons · Finnhub API · $9.45 BOM · 100% open source

What it does

PocketStock is a tiny desktop gadget that pulls live stock quotes from the Finnhub API over WiFi and displays them on a crisp 0.96" OLED. Scroll through your watchlist, open a ticker, and get:

• 💵 Live price, refreshed every 3 seconds
• 📉 Change since previous close
• 📊 Sparkline chart of the last 20 price updates
• 🕐 Real-time clock synced via NTP
• 🔔 Market open/closed indicator (knows NYSE hours, including the 9:30 open)

Navigation is a simple three-button menu system — up, down, select — with long-press to go back. No touchscreen, no app, no subscription.

Is it going to replace the military-grade supercomputer in your other pocket? No. But it's a dedicated, glanceable market display that doesn't buzz, doesn't distract, and doesn't try to sell you anything. It just tells you the number. (V1 runs off USB power — true pocket portability is on the roadmap.)

Oh, and there's Pong hidden in the settings menu. Because every good gadget needs a game.

Hardware

The entire build costs $9.45 in parts:

Plus a custom PCB and a 3D-printed enclosure (STLs in cad/psv1-stls). Full parts list with supplier links: hardware/bill-of-materials-psv1.csv

Everything you need to reproduce or remix the board is included: ready-to-fab gerbers in hardware/gerbers, the full KiCad project (schematic + board layout) in hardware/pcb, and a STEP model of the assembled PCB for designing your own enclosure around it.

Wiring

Buttons are active-low using the ESP32's internal pull-ups — wire each button between its GPIO and GND. No external resistors needed.

Schematic

Full vector version: hardware/schematics/psv1-sch.pdf · KiCad source: hardware/schematics

Build it

1. Print the enclosure

Print the three STLs in cad/psv1-stls: base-v3.stl, lid-v3.stl, and button-v3.stl (×3).

2. Order the PCB

Upload the files in hardware/gerbers to your favorite fab (JLCPCB, PCBWay, OSH Park). Prefer to breadboard first? The schematic above is all you need — or open the full KiCad project in hardware/pcb to modify the board itself.

3. Flash the firmware

1. Install the Arduino IDE and add ESP32 board support (Boards Manager → search "esp32" → install Espressif's package).
2. Install these libraries via Library Manager:
   • Adafruit SSD1306
   • Adafruit GFX Library
   • ArduinoJson
3. Open firmware/PocketStockV1/PocketStockV1.ino and set your own values:

const char* ssid   = "YOUR_WIFI_SSID";       // open networks supported; add a password arg to WiFi.begin() for secured ones
const char* apiKey = "YOUR_FINNHUB_API_KEY"; // free at https://finnhub.io

4. Edit the stocks[] array to build your own watchlist — any Finnhub-supported ticker works.
5. Select ESP32C3 Dev Module as the board, hit upload, and watch the boot logo roll.

Note: Finnhub's free tier allows 60 calls/minute. PocketStock polls every 3 seconds (20/min), so you're well within limits — but get your own free key rather than sharing one.

Controls

Gallery

Repo map

├── cad/
│   ├── psv1-stls/    3D-printable enclosure (base, lid, buttons)
│   └── renders/      Enclosure renders
├── docs/             Architecture doc — how the firmware & hardware work
├── firmware/         ESP32-C3 Arduino sketch
└── hardware/
    ├── gerbers/      Ready-to-fab PCB files
    ├── pcb/          Full KiCad project + STEP model + board renders
    ├── schematics/   Schematic (PNG, PDF, KiCad source)
    └── bill-of-materials-psv1.csv

Roadmap

• WiFi provisioning (no hardcoded SSID)
• Store API key + watchlist in flash, editable from the device
• Percent-change view and daily high/low
• Crypto ticker support
• Battery power + deep sleep

License

See LICENSE. Fork it, print it, mod it — and if you build one, open an issue with a photo. I'd love to see it.