🚀 ESP32 LED Matrix BTC Ticker

A PlatformIO project that displays Bitcoin price updates on a 32x16 LED matrix using FastLED, NeoMatrix, and more.

🛠️ Hardware Requirements

• ESP32 Development Board
• 32x16 WS2812B LED Matrix (512 LEDs total)
• Power supply (5V, adequate for your LED count)
• Jumper wires

🔌 Wiring (WROOM ESP32)

• LED Matrix Data Pin → ESP32 GPIO 5
• LED Matrix 5V → External 5V Power Supply (optional, but recommended)
• LED Matrix GND → ESP32 GND + Power Supply GND

💻 Software Setup

Tooling/Extensions

Windsurf, VS Code

1. Install PlatformIO
2. Install VS Code with PlatformIO extension (recommended)

Cursor

1. Cursor currently is not licensed by Microsoft to use their cpptools extension. Workaround is to install an older version: https://github.com/microsoft/vscode-cpptools/releases/download/v1.24.4/cpptools-macOS-arm64.vsix
2. PlatformIO is also not listed in the Open VSX Registry (non-Microsoft Extensions Marketplace). Manually download the PlatformIO vsix extension file: https://marketplace.visualstudio.com/_apis/public/gallery/publishers/platformio/vsextensions/platformio-ide/3.3.4/vspackage?targetPlatform=darwin-arm64
3. Manually install these .vsix extensions (cpptools first) with Command Palette: Extensions: Install from VSIX

⚙️ Configuration

1. Copy the configuration template:

   cp include/config.h.template include/config.h

2. Edit include/config.h and update with your actual credentials:

   #define WIFI_SSID "YOUR_WIFI_SSID"
   #define WIFI_PASSWORD "YOUR_WIFI_PASSWORD"
   #define COINGECKO_API_KEY "YOUR_COINGECKO_API_KEY"

3. [Optional] Customize hostname by editing platformio.ini:

   [platformio]
   hostname = my-custom-name

   This automatically configures both the device hostname and OTA upload target.

   Note: config.h is in .gitignore to keep your credentials private.

🔨 Building and Uploading

1. Clone/navigate to this repository
2. PlatformIO should automatically detect and initialize the project. If not, PIO Home->Open the directory.

Using VS Code + PlatformIO

• Open the project folder in VS Code
• Click the PlatformIO icon in the sidebar
• Click "Build" to compile
• Connect your ESP32 via USB
• Click "Upload" to flash the firmware
• Click "Monitor" to view serial output

Using Command Line

# Navigate to project directory
cd esp-led-btc

# Install dependencies and build
pio run

# Upload to ESP32 (make sure it's connected via USB)
pio run --target upload

# Monitor serial output
pio device monitor --baud 115200

⚡ How It Works

1. Startup: ESP32 connects to WiFi and initializes the LED matrix
2. Price Updates: Asyncronously fetches BTC price from CoinDesk API (using timer interrupts), calculates deltas from OHLC
3. Drawing: Main loop, using a variety of LED libs

📡 Over-The-Air (OTA) Updates

Update firmware wirelessly without USB connection using PlatformIO environments.

🚀 Usage

PlatformIO Extension (Recommended)

1. First upload: Select esp32dev environment → Click "Upload"
2. Wireless updates: Select esp32dev_ota environment → Click "Upload"

Command Line

# First upload via USB
pio run --environment esp32dev --target upload

# Wireless updates via OTA (uses hostname from platformio.ini)
pio run --environment esp32dev_ota --target upload

# Monitor serial output (works with both environments)
pio device monitor --baud 115200

🎨 Visual OTA Feedback

The LED matrix shows OTA progress:

• 🔵 Blue: Update starting
• 🟣 Purple: Progress bar
• 🟢 Green: Success
• 🔴 Red: Failed

🔧 Troubleshooting OTA

• Device not found: Ensure device is on same network and <hostname>.local is reachable (check platformio.ini for configured hostname)
• Custom hostname not working: Verify hostname is correctly set in platformio.ini under [platformio] section
• mDNS issues: Use IP directly: pio run --environment esp32dev_ota --target upload --upload-port 192.168.1.100
• Wrong environment: Use esp32dev_ota for wireless updates
• Stuck in OTA: Power cycle the device

📺 Serial Monitor Output

USB

You should see output along the lines of:

ESP32 LED Matrix BTC Ticker Starting...
Connecting to WiFi........
WiFi connected! IP address: 192.168.1.100
mDNS responder started
OTA Ready
IP address: 192.168.1.100
Setup complete!
Fetching BTC price...
BTC Price: $XXXXX USD
Last Updated: Dec 8, 2023 19:30:00 UTC

Remote

Serial monitor for a remotely deployed device can be accessed at: http://<hostname>.local (hostname configured in platformio.ini, default: http://btc-ticker.local)

Matrix Layout

• Size: 32x16 pixels
• Origin: Bottom-right
• Layout: Column-major with zigzag wiring

🔧 Troubleshooting

• No WiFi connection: Check SSID/password in config.h
• No LED response: Verify wiring and power supply
• Compilation errors: Ensure PlatformIO dependencies are installed
• Upload fails: Check ESP32 is in bootloader mode and correct port is selected

🗺️ Roadmap:

1. Non-blocking async HTTP fetch ✅
2. OTA (Over the Air) update support ✅
3. Text: Restyle, add more animations + fonts
4. Animated background effects
5. Chart (line or bar)