Kicad temp

┌─────────────────┐    BLE Advertisement    ┌─────────────────┐
│   Sensor Node   │ ──────────────────────► │  Raspberry Pi   │
│                 │                         │     Host        │
│ • nRF52840      │                         │                 │
│ • BME280        │                         │ • BLE Scanner   │
│ • Battery       │                         │ • Data Logger   │
│ • Adaptive PM   │                         │ • SQLite DB     │
└─────────────────┘                         └─────────────────┘

# Install nRF Connect SDK
# Follow: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/gs_installing.html

# Clone and build
cd mcu_firmware
./build.sh

# Flash to device
west flash -d build

# Install dependencies
sudo apt update
sudo apt install python3-pip python3-venv bluetooth bluez

# Create virtual environment
cd pi_host
python3 -m venv venv
source venv/bin/activate

# Install Python packages
pip install -r requirements.txt

# Run scanner
python3 sensor_scanner.py

# List known devices
python3 data_viewer.py --list-devices

# View recent data
python3 data_viewer.py --hours 24 --stats

# Filter by device
python3 data_viewer.py --device AA:BB:CC:DD:EE:FF

struct sensor_adv_data {
    uint8_t version;           // Protocol version (1)
    uint8_t tier;              // Power tier (0-3)
    uint16_t battery_mv;       // Battery voltage in mV
    int16_t temperature;       // Temperature * 100 (°C)
    uint16_t pressure;         // Pressure * 10 (hPa)
    uint16_t humidity;         // Humidity * 100 (%)
    uint32_t timestamp;        // Unix timestamp
};

CREATE TABLE sensor_data (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    device_address TEXT NOT NULL,
    device_name TEXT,
    timestamp DATETIME NOT NULL,
    temperature REAL,
    pressure REAL,
    humidity REAL,
    battery_mv INTEGER,
    power_tier INTEGER,
    rssi INTEGER,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP
);

-- Average temperature by hour
SELECT strftime('%Y-%m-%d %H:00:00', timestamp) as hour,
       AVG(temperature) as avg_temp
FROM sensor_data 
GROUP BY hour 
ORDER BY hour DESC;

-- Battery status over time
SELECT timestamp, battery_mv, power_tier
FROM sensor_data 
WHERE device_address = 'AA:BB:CC:DD:EE:FF'
ORDER BY timestamp DESC;

# Monitor MCU serial output
west espressif monitor -d build

# Check BLE devices
sudo hcitool lescan

# Monitor system logs
journalctl -u sensor-scanner -f

# Check database integrity
sqlite3 sensor_data.db "PRAGMA integrity_check;"

[Unit]
Description=BLE Sensor Scanner
After=bluetooth.service
Wants=bluetooth.service

[Service]
Type=simple
User=pi
WorkingDirectory=/home/pi/sensor-system/pi_host
Environment=PATH=/home/pi/sensor-system/pi_host/venv/bin
ExecStart=/home/pi/sensor-system/pi_host/venv/bin/python sensor_scanner.py
Restart=always
RestartSec=10

[Install]
WantedBy=multi-user.target

sudo systemctl enable sensor-scanner
sudo systemctl start sensor-scanner

temp-sensor-code/
├── mcu_firmware/           # nRF52840 firmware
│   ├── src/               # Source files
│   ├── boards/            # Device tree overlays
│   ├── prj.conf          # Zephyr configuration
│   └── build.sh          # Build script
├── pi_host/              # Raspberry Pi application
│   ├── sensor_scanner.py # Main scanner
│   ├── data_viewer.py    # Data query tool
│   └── requirements.txt  # Python dependencies
└── README.md             # This file