2.4 KiB
2.4 KiB
DigiRadio — Firmware
⚠️ Status: in active development. The firmware will be released here after hardware bring-up and validation on the first prototype. Publishing firmware before it can be tested on real hardware would not be meaningful, so this directory currently documents the planned architecture only.
Target Platform
- Host MCU: Espressif ESP32-S3 (native USB, Wi-Fi, BLE)
- Toolchain: ESP-IDF (planned)
- DSP tooling: Analog Devices SigmaStudio for the ADAU1701 audio flow
Planned Architecture
The ESP32-S3 is the system host and orchestrates the three audio subsystems over three separate buses.
Boot sequence
- ESP32-S3 releases the ADAU1701 reset line (GPIO-controlled).
- ESP32-S3 loads the compiled SigmaStudio program into the DSP program/parameter RAM over I²C (host-load model; on-board self-boot EEPROM is a DNP option).
- ESP32-S3 starts the DSP core.
- ESP32-S3 loads the Si4684 firmware/patch over SPI.
- FSC-BT1035 is brought up over UART (Feasycom ASCII command set).
Runtime control
- Audio parameters (volume, EQ, source mix): written to the ADAU1701 safeload registers over I²C to avoid audio pops.
- Tuner: DAB/FM band and station control via Si4684 over SPI.
- Bluetooth: A2DP source control (aptX Adaptive), pairing and status via FSC-BT1035 UART commands.
- Connectivity: optional Wi-Fi internet-radio stream injected into the DSP via a second I²S input.
Bus Map (summary)
| Bus | Devices | Notes |
|---|---|---|
| I²C | ADAU1701, MAC EEPROM, (self-boot EEPROM DNP) | single system bus; distinct addresses |
| SPI | Si4684 | firmware/patch load + control |
| UART | FSC-BT1035 | ASCII command set, 4-wire with flow control |
| I²S | Si4684 → DSP → BT1035 (+ ESP32 in) | DSP is I²S master (48 kHz) |
See the Technical Reference Manual for the complete pin assignment and address map.
Roadmap
- ESP32-S3 project skeleton (ESP-IDF)
- ADAU1701 program loader (SigmaStudio export → I²C write)
- Si4684 firmware loader + DAB/FM control
- FSC-BT1035 UART driver (A2DP source, aptX Adaptive)
- Runtime control (volume / EQ / source) via safeload
- Wi-Fi internet-radio source (optional)
- Bring-up notes and validated example configuration
License
Firmware in this directory is licensed under the MIT License once released.