# Xterra Overland Power & Monitoring Dashboard Architecture

## Overview

The Xterra Overland Power & Monitoring Dashboard is a distributed monitoring and control system consisting of:

* Raspberry Pi Pico 2 W dashboard module
* ESP32 cargo-area controller
* RS-485 wired communications
* WiFi backup communications
* Touchscreen dashboard interface

The system is designed to operate completely offline and continue functioning even when WiFi is disabled.

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## System Goals

* Monitor house battery status
* Monitor fridge temperatures
* Monitor rear seat temperature
* Monitor outside ambient temperature
* Control Starlink power
* Control fridge power
* Provide a dashboard display while driving
* Expand later to vehicle telemetry and trip logging

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## Dashboard Module

### Hardware

* Raspberry Pi Pico 2 W
* 3.5" touchscreen
* Powered by 5V from cargo-area buck converter

### Responsibilities

* Display information
* Accept touch input
* Send commands to controller
* Display alarms and warnings
* Provide user configuration interface

### Communications

Primary:

* RS-485 over CAT5

Secondary:

* WiFi HTTP API

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## Controller Module

### Hardware

* ESP32 relay board
* House battery connection
* Bosch-style automotive relays

### Responsibilities

* Read sensors
* Interface with BMS
* Control relays
* Serve API data
* Handle logging

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## Temperature Sensors

### Planned Sensors

1. Fridge Zone 1
2. Fridge Zone 2
3. Rear Seat Temperature
4. Outside Ambient Temperature
5. Battery Compartment Temperature (future)

### Interface

* DS18B20
* Shared 1-Wire bus
* Connected to ESP32

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## Battery Monitoring

### Planned BMS

* Xiaoxiang / JBD Bluetooth BMS

### Data Collected

* State of Charge
* Voltage
* Current
* Remaining Capacity
* Runtime Estimate
* Battery Temperature
* Cell Voltages
* Cell Imbalance

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## Relay Control

### Current Loads

* Starlink
* Fridge

### Future Loads

* Inverter
* Camp Lights

### Design

ESP32 relay outputs SHALL NOT carry load current.

ESP32 relays will only energize Bosch-style 30A/40A automotive relays.

All loads must be fused appropriately.

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## Communications

### Primary

RS-485 over CAT5

Advantages:

* Reliable
* Noise resistant
* Independent of WiFi
* Works while driving

### Backup

WiFi HTTP API

Used for:

* Phone access
* Web dashboard
* Configuration
* Future Home Assistant integration

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## WiFi Rules

### Starlink OFF

* Dashboard operational
* Sensors operational
* Relay control operational
* WiFi disabled
* Web dashboard disabled

### Starlink ON

* WiFi enabled
* Web dashboard enabled
* Remote access enabled

### Override

User may temporarily enable WiFi for troubleshooting.

Default timeout:
10 minutes.

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## Dashboard Behavior

### Ignition ON

* Screen active
* Full brightness

### Ignition OFF

* Screen black
* Pico remains powered
* Touch input remains active

Touching screen:

* Wake display
* Display dashboard
* Auto-sleep after timeout

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## Future Expansion

### Vehicle Data

* OBD-II
* CAN bus
* Fuel level
* RPM
* Coolant temperature
* Vehicle speed

### Navigation

* GPS
* Trip logging

### Connectivity

* MQTT
* Home Assistant
* InfluxDB
* Grafana

### Additional Sensors

* Additional DS18B20 sensors
* Voltage sensors
* Current sensors
* Environmental monitoring