# Hardware

This directory contains all hardware designs, schematics, BOMs, and mechanical files for the KosmoConnect project.

## Directory Structure

```
hardware/
├── enviro-node/          # Solar-powered environmental station
│   ├── pcb/              # KiCad / EasyEDA project files
│   ├── enclosure/        # 3D models, STL files, mounting hardware
│   ├── sensors/          # Sensor datasheets, integration notes
│   ├── power/            # Solar panel, battery, charge controller specs
│   └── bom/              # Bill of materials, sourcing guides
├── infrastructure-node/  # Bridge node hardware (may be off-the-shelf)
│   ├── off-the-shelf/    # Recommended COTS devices (T-Beam, RAK, etc.)
│   └── custom/           # Optional custom bridge PCB designs
└── common/               # Shared libraries, footprints, symbols
    ├── kicad-libs/
    └── 3d-models/
```

## Enviro-Node Hardware Overview

### Brain
- **Option A**: ESP32-S3-WROOM-1 (dual-core, WiFi/BT if needed, good dev ecosystem)
- **Option B**: nRF52840 (lower power, native Meshtastic support, harder dev)

**Decision**: Start with ESP32-S3 for rapid development; evaluate nRF52840 for v2 power optimization.

### Radio
- **Semtech SX1262** (915 MHz NA / 868 MHz EU / 433 MHz regions)
- TCXO for stability across temperatures
- External antenna (SMA or u.FL)

### Sensors (v1)
- **BME680**: Temperature, humidity, pressure, VOC/gas
- **SPS30**: Particulate matter (PM1.0, PM2.5, PM4.0, PM10)
- **Anemometer**: Davis 6410 or custom 3-cup + wind vane
- **Rain gauge**: Optional tipping bucket (WH-SP-RG)

### Power System
- **Solar Panel**: 10W monocrystalline
- **Battery**: 3.2V 32700 LiFePO4 6000mAh (safer than LiPo for outdoor unattended)
- **Charge Controller**: Custom MPPT or CN3791-based board
- **Power Management**: TPS63001 buck-boost, load switches for sensors

### Enclosure
- Polycarbonate or ABS outdoor enclosure
- Solar panel mounted on lid or external pole
- Glands for antenna and sensor cables
- Passive ventilation for accurate T/H readings

## Power Budget (v1 Estimate)

| Component | Active Current | Sleep Current | Duty Cycle | Daily mAh |
|-----------|---------------|---------------|------------|-----------|
| ESP32-S3 | 80mA | 15µA | 1% | ~22 |
| SX1262 | 10mA TX | 0.5µA | 0.1% | ~1 |
| BME680 | 3mA | 0.15µA | 1% | ~1 |
| SPS30 | 60mA | 0mA | 1% | ~15 |
| Anemometer | 0mA (passive) | 0mA | 100% | 0 |
| Quiescent | - | 0.5mA | 99% | ~12 |
| **Total** | | | | **~51 mAh/day** |

A 10W panel in winter (2h effective sun) produces ~400mAh/day. A 6000mAh battery provides ~80 days of autonomy. This is viable but tight; v2 will aggressively optimize sleep current.

## Recommended Infrastructure Node Hardware

For rapid deployment, use off-the-shelf Meshtastic devices:
- **LILYGO T-Beam 868/915MHz** + ESP32 (good for WiFi/LTE backhaul)
- **RAKwireless WisGate Edge Lite 2** (if building a dedicated gateway)
- **Raspberry Pi 4 + RAK2287 HAT** (for a more powerful Linux-based bridge)

## Design Files

- [Enviro-Node v1 BOM](./enviro-node/bom/bom-v1.md) *(placeholder)*
- [Power Budget Spreadsheet](./enviro-node/power/budget-v1.ods) *(placeholder)*
- [Enclosure Assembly Guide](./enviro-node/enclosure/assembly-v1.md) *(placeholder)*