🌡️ AranetBar

A single-file Swift macOS menu bar monitor for the Aranet4 indoor air quality sensor — live CO₂, temperature, humidity, atmospheric pressure, battery, and on-device history charts over Bluetooth Low Energy.

Companion Repository: AranetBar lives alongside our Aranet4 Bluetooth protocol tools in The-Focus-AI/aranet4-bluetooth.

Download & Quick Start

Prebuilt Universal .app

1. Download the latest AranetBar-<version>.zip from AranetBar Releases.
2. Move AranetBar.app to /Applications and clear Gatekeeper quarantine once:

xattr -dr com.apple.quarantine /Applications/AranetBar.app
open /Applications/AranetBar.app

Run or Build from Source

git clone https://github.com/The-Focus-AI/aranet4-bluetooth.git
cd aranet4-bluetooth/swift

# Run directly as a Swift script
./aranetbar.swift --once

# Or build the standalone universal AranetBar.app bundle (ai.thefocus.aranetbar)
./build.sh
open AranetBar.app

Features

• 🟢 Passive BLE advertisements — Reads live CO₂, temperature, relative humidity, pressure, and battery without draining sensor battery via active GATT polling
• 📈 On-board history sync & charts — Downloads stored sensor history on demand, caches locally under ~/Library/Application Support/AranetBar/history/, and renders honest gap-aware charts
• 🧭 Multi-sensor selection — Automatically tracks the nearest Aranet4 or pins to a chosen sensor
• 🪟 Notch & reopen aware — Automatically opens the History window if macOS hides the menu bar item behind the MacBook camera housing, or when AranetBar.app is reopened in Finder
• 🧪 Headless CLI flags — --once, --dump-menu, --history, --render-history, and --version

Technical Identity

Property	Value
Bundle Identifier	ai.thefocus.aranetbar
Source File	swift/aranetbar.swift
Minimum macOS	macOS 13.0+ (Universal arm64 + x86_64)
Permissions	Bluetooth (NSBluetoothAlwaysUsageDescription) — Smart Home Integration enabled in the Aranet Home app

Further Reading

• 📦 Download Prebuilt Releases
• 🔧 View Swift Source (swift/)
• 📖 How I Built AranetBar