469 lines
4.3 KiB
Markdown
469 lines
4.3 KiB
Markdown
# HubAudio System Architecture
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- Status: Draft
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- Date: 2026-08-01
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- Document Type: System Architecture
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# 1. Overview
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HubAudio is a modular digital audio platform designed around a centralized
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audio processing architecture.
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The system separates three main functional domains:
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- Control Domain
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- Audio Domain
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- Time Domain
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Each domain has a clearly defined responsibility.
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The architecture is based on the principle:
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ESP32-S3 manages the system.
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ADAU1467 manages the audio.
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The clock domain synchronizes the orchestra.
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---
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# 2. High Level Architecture
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HUBAUDIO
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CONTROL DOMAIN
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ESP32-S3
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WiFi / Network / UI
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SPI
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+---------------+---------------+
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ADAU1467 Si4684
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Audio Processor Radio Receiver
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AUDIO DOMAIN
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+-------+-------+-------+-------+
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ESP32 Si4684 BT RX Optical Other
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ADAU1467
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DSP / Routing / Mixing
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+-------+-------+-------+
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CODEC BT TX Optical Out
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TIME DOMAIN
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Audio Clock Tree
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MCLK / BCLK / LRCLK
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---
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# 3. Functional Domains
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# 3.1 Control Domain
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The Control Domain is responsible for system management.
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Main component:
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ESP32-S3
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Responsibilities:
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- network connectivity
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- streaming services
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- user interface
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- configuration management
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- firmware update coordination
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- device supervision
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Communication:
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ESP32-S3
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SPI
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Audio peripherals
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The Control Domain does not transport real-time audio.
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---
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# 3.2 Audio Domain
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The Audio Domain is centered around the ADAU1467.
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The ADAU1467 is responsible for:
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- DSP processing
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- audio routing
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- mixing
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- digital effects
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- format conversion
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- audio synchronization
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Audio sources:
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ESP32-S3
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Si4684
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Bluetooth RX
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Optical Input
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Audio destinations:
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CODEC/DAC
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Bluetooth TX
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Optical Output
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The audio transport uses:
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I2S
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---
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# 3.3 Time Domain
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The Time Domain provides the synchronization reference.
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The ADAU1467 is the audio clock master.
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The clock distribution provides:
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- MCLK
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- BCLK
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- LRCLK
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Clock distribution:
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ADAU1467
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Audio Clock Master
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Clock Buffer
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+-----------+-----------+
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CODEC Si4684 BT
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---
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# 4. Component Roles
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## ESP32-S3
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Role:
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System Controller + Audio Source
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Functions:
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- network audio streaming
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- system management
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- configuration
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Inside Audio Domain:
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I2S Source
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---
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## ADAU1467
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Role:
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Audio Domain Master
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Functions:
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- DSP
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- routing
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- mixing
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- clock generation
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Interfaces:
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SPI -> Configuration
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I2S -> Audio
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Clock -> Synchronization
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---
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## Si4684
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Role:
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Digital Radio Audio Source
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Functions:
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- FM reception
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- DAB/DAB+
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- digital audio output
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Interfaces:
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SPI -> Control
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I2S -> Audio
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---
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## Bluetooth Modules
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Role:
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Wireless Audio Interfaces
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Bluetooth RX:
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BT Audio
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I2S
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ADAU1467
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Bluetooth TX:
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ADAU1467
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I2S
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BT Transmitter
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---
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## Digital Converters
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Optical interfaces are handled through dedicated conversion stages.
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Input:
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SPDIF
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DECODEC
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I2S
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ADAU1467
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Output:
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ADAU1467
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I2S
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ENCODEC
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SPDIF
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---
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# 5. Design Philosophy
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HubAudio follows a distributed intelligence model.
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The ESP32-S3 provides connectivity and supervision.
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The ADAU1467 provides audio intelligence.
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Dedicated peripherals provide specialized functions.
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The architecture avoids making the microcontroller responsible for
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time-critical audio processing.
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---
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# 6. Expansion Strategy
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The architecture allows future integration of:
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- additional audio sources
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- additional DSP processing
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- microphones
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- sensors
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- alternative wireless interfaces
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Expansion follows the same principle:
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Control:
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SPI
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Audio:
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I2S
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Synchronization:
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Clock Domain
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---
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# 7. Summary
|
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HubAudio is structured around three independent but coordinated planes:
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CONTROL PLANE
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ESP32-S3
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SPI
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AUDIO PLANE
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ADAU1467
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I2S
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TIME PLANE
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ADAU1467
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Clock Distribution
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This separation defines the fundamental architecture of HubAudio. |