MaBell Project Plan v0: Foundation #

Plan: MaBell Bluetooth Gateway: Project Plan · Next: v1: On the bench

Legend: ✅ Complete | 🔄 In Progress | ⏳ Planned

Requirements, design and the first firmware: the base every prototype builds on. The firmware came first so the prototypes have something to talk to the hardware. Status: done, 2026-10-10.

Done when:

• Requirements, constraints and acceptance criteria are written, with a risk register.
• The system, power, audio and firmware design is finished, with a verification plan mapping requirements to tests.
• The firmware builds and runs on the ESP32: Bluetooth HFP, the call state machine, tone generation, NVS configuration and logging.
• MaBell is a Deevnet tenant: its state over MQTT, its events in the central log store, and a Grafana dashboard.

Not in v0: any hardware beyond the ESP32 itself (v1 onward); firmware release tagging (v1).

Requirements & Constraints ✅ #

Define what success means before building.

• ✅ User scenarios (incoming/outgoing calls, edge cases)
• ✅ Functional requirements (FR-xxx)
• ✅ Non-functional requirements (latency, audio quality, reliability)
• ✅ Electrical & mechanical constraints
• ✅ Acceptance criteria for each requirement
• ✅ Risk register (top technical risks + mitigations)

Architecture & Design ✅ #

Translate requirements into a complete system design.

• ✅ System block diagram
• ✅ Power architecture & protection strategy
• ✅ Audio signal chain & gain staging plan
• ✅ Hook switch, dial pulse, and ring detection design
• ✅ Bluetooth integration architecture
• ✅ Firmware architecture & state machine definition
• ✅ Interface specifications (electrical, audio, software)
• ✅ Verification & test plan (requirements → tests mapping)

Firmware Development ✅ #

The ESP32 firmware, built first so the prototypes have something to talk to the hardware.

• ✅ ESP32 base firmware & build system
• ✅ Bluetooth HFP profile implementation
• ✅ Call state machine implementation
• ✅ Tone generation (dial tone, ringback, busy, reorder and the other call-progress tones)
• ✅ Configuration storage (NVS schema)
• ✅ Logging & diagnostics

Deevnet Tenant ✅ #

• ✅ The gateway’s state published over MQTT
• ✅ Its events in the central log store
• ✅ A Grafana dashboard for the gateway