# Hardware Prototype Specs

## Components List

### Main Unit (Faux Rocher)
- Raspberry Pi 4 (4GB)
- Waveshare 4G HAT
- Solar charge controller (MPPT)
- LiFePO4 Battery (12V)

### Underwater Unit
- Hydrophone
  - Reco: 192 kHz sampling, useful band 5 Hz–118 kHz
- Pressure + temperature sensor (MS5837-30BA)
- Conductivity sensor/probe (TBD)

### Cables & Connectors
- IP68 underwater connectors
- Shielded audio cable (~5m)

## Power / Energy Budget (estimation)

**Inputs (production)**
- Solar panel: **100 W**
- Assumption: ~4 h/day equivalent full sun, ~70% end-to-end efficiency (MPPT + wiring + battery charge)
- Energy/day (order of magnitude): **~280 Wh/day**

**Outputs (consumption)** (order-of-magnitude, to be measured)
- Raspberry Pi: ~5 W
- 4G modem: ~2–6 W (depending on uplink)
- ADC + sensors: ~0.5–1.5 W
- Total average: **~8–12 W** → **~190–290 Wh/day**

**Battery sizing example (12V LiFePO4)**
- 24h autonomy: ~16–24 Ah
- 3 days autonomy: **~50–75 Ah**

**Transmission strategy**
- If 4G throughput is OK: stream raw audio continuously.
- If throughput is low: apply light denoise/filtering + compression to avoid transferring mostly noise.
- If very low: send clips/events/features.