Meshtastic-Android/docs/decisions/ble-strategy.md

Decision: BLE KMP Strategy

Date: 2026-03-16 | Status: Decided — Fully Migrated to Kable

Context

core:ble needed to support non-Android targets. Nordic's Kotlin-BLE-Library, while mature on Android and actively tested in the app, was primarily Android/iOS focused and lacked support for Desktop (JVM) targets. Kable natively supports all Kotlin Multiplatform targets (Android, Apple, Desktop/JVM, Web).

Initially, we implemented an Interface-Driven "Nordic Hybrid" Abstraction (keeping Nordic on Android behind commonMain interfaces) to wait and see if Nordic expanded their KMP support.

However, as Desktop integration advanced, we found the need for a unified BLE transport.

Decision

Migrate entirely to Kable:

• We migrated all BLE transport logic across Android and Desktop to use Kable.
• The commonMain interfaces (BleConnection, BleScanner, BleDevice, BluetoothRepository, etc.) remain, but their core implementations (KableBleConnection, KableBleScanner) are now entirely shared in commonMain.
• The Android-specific Nordic dependencies (no.nordicsemi.kotlin.ble:*) and the Nordic DFU library were completely excised from the project.
• OTA Firmware updates on Android were successfully refactored to use the Kable-based BleOtaTransport.

Consequences

• Maximal Code Deduplication: The BLE implementation is completely shared across Android and Desktop in core:ble/commonMain.
• Future-Proofing: Adding an iosMain target in the future will be trivial, as it can leverage the same shared Kable abstractions.
• Lost Nordic Mocks: Kable lacks the comprehensive mock infrastructure of the Nordic library. Consequently, several complex BLE OTA unit tests had to be deprecated. Re-establishing this test coverage using custom Kable fakes is an ongoing technical debt item.

Archive

• Original Hybrid Analysis: archive/ble-kmp-strategy.md
• Original Abstraction Plan: archive/ble-kmp-abstraction-plan.md