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Release 2.0.0

Release Date: April 24, 2026

Release 2.0.0 is a major release delivering the timeless protocol for the Hubble Terrestrial (BLE) Network, along with a set of API refinements that required a major version bump.

Overview

The headline change in 2.0.0 is a new counter source mode that lets BLE devices participate in the Hubble Terrestrial Network without a real-time clock. Previously, devices had to know the current Unix time before they could generate valid advertisement packets. With the device uptime counter source, a device derives its EID counter purely from elapsed uptime, removing the dependency on time synchronization entirely. This unlocks simpler hardware designs and more robust firmware that does not need to handle clock loss or NTP failures.

In addition, this release ships an early preview of the Satellite Network module (pre-production) and includes several API renames that form the breaking changes driving the MAJOR version increment.

See Breaking Changes before upgrading from 1.x.

Key Features

Timeless Protocol for BLE Terrestrial Network

Devices can now operate without a real-time clock by selecting the device uptime counter source (CONFIG_HUBBLE_COUNTER_SOURCE_DEVICE_UPTIME). In this mode:

  • The EID counter is derived from device uptime rather than Unix time, so no time synchronization is required.

  • hubble_init() accepts an initial counter value of 0 (start at epoch 0) or a previously saved counter for continuity across reboots.

  • hubble_counter_get() exposes the current counter value so applications can persist it to flash and resume from a known state after a power cycle.

  • The EID rotation period is now configurable via CONFIG_HUBBLE_EID_ROTATION_PERIOD_SEC, giving integrators control over the trade-off between privacy and power consumption.

  • The EID pool size is fixed at 128, which is reflected in the counter wrap behavior for uptime mode.

The original Unix time mode (CONFIG_HUBBLE_COUNTER_SOURCE_UNIX_TIME) is unchanged and remains the default for devices that do have a reliable clock.

New BLE Terrestrial APIs

  • HUBBLE_BLE_ADV_HEADER_SIZE — public constant (12) exposing the fixed overhead added to every BLE advertisement, simplifying output buffer sizing.

  • hubble_counter_get() — returns the current EID time counter value regardless of counter source mode.

  • EID rotation period defined via CONFIG_HUBBLE_EID_ROTATION_PERIOD_SEC.

Platform Updates

  • Zephyr: Bumped to Zephyr 4.4.0.

  • FreeRTOS: PSA crypto backend support added (CONFIG_HUBBLE_NETWORK_CRYPTO_PSA).

  • FreeRTOS: Satellite network port implemented; disabled by default.

  • ESP-IDF: Satellite protocol version is now configurable.

  • ESP-IDF: Added version check for the crypto implementation at build time.

Documentation

  • Configuration reference auto-generated from Kconfig — always in sync with the actual build options.

  • Per-branch documentation published automatically to GitHub Pages subdirectories.

  • Clarified hubble_rand_get is only required for the Satellite Network.

  • Clarified key pointer lifetime requirement in hubble_init() and hubble_key_set().

Satellite Network (Pre-Production)

Warning

The Satellite Network module is pre-production and not intended for production deployments. APIs and on-air protocol details may change in future releases.

The Satellite Network module is included for early evaluation:

  • Packet construction: hubble_sat_packet_get() builds a satellite packet from a payload (up to HUBBLE_SAT_PAYLOAD_MAX bytes).

  • Frame splitting: hubble_sat_packet_frames_get() divides a packet into up to four radio frames, each with its channel assignment.

  • Transmission: hubble_sat_packet_send() transmits a packet with configurable reliability (HUBBLE_SAT_RELIABILITY_NONE, HUBBLE_SAT_RELIABILITY_NORMAL, HUBBLE_SAT_RELIABILITY_HIGH).

Pass Prediction (Ephemeris)

  • hubble_sat_satellites_set() — load orbital parameters for one or more satellites.

  • hubble_next_pass_get() — compute the next pass over a geographic point.

  • hubble_next_pass_region_get() — compute the next pass over a rectangular geographic region.

  • Multi-satellite pass computation: all configured satellites are evaluated and the earliest pass is returned.

Sample Applications

New samples shipping with 2.0.0:

  • Satellite Continuous (Zephyr): Demonstrates continuous satellite packet transmission (samples/zephyr/sat-continuous).

Existing samples:

  • BLE Beacon (Zephyr, FreeRTOS/TI, ESP-IDF)

  • BLE Network (Zephyr)

API Highlights

BLE Terrestrial Network APIs:

  • hubble_counter_get() — get the current EID time counter value

  • hubble_ble_advertise_expiration_get() — get the time remaining until the BLE advertisement expires

  • HUBBLE_BLE_ADV_HEADER_SIZE — fixed advertisement header size constant

Satellite Network APIs (pre-production):

  • hubble_sat_packet_get() — build a packet from payload bytes

  • hubble_sat_packet_frames_get() — split a packet into radio frames

  • hubble_sat_packet_send() — transmit a packet via satellite

  • hubble_sat_satellites_set() — configure orbital parameters

  • hubble_next_pass_get() — predict next pass over a point

  • hubble_next_pass_region_get() — predict next pass over a region

Breaking Changes

This release contains the following incompatible API changes.

UTC identifiers renamed to Unix time

Public symbols containing utc have been renamed for consistency:

1.0 symbol

2.0 symbol

hubble_init() utc_time parameter

initial_time parameter

hubble_utc_set()

hubble_time_set()

Satellite API redesigned

The experimental satellite API from 1.0 has been fully redesigned. All 1.0 satellite functions are removed:

Removed (1.0)

Replacement (2.0)

hubble_sat_init()

(initialization now handled internally)

hubble_sat_enable()

(managed by the radio port)

hubble_sat_disable()

(managed by the radio port)

hubble_sat_transmit_packet()

hubble_sat_packet_send()

hubble_sat_packet_get(pkt, dev_id, payload, len)

hubble_sat_packet_get() (pkt, payload, len)

hubble_sat_packet_frames_get() is a new function with no 1.0 equivalent.

Migration Guide

  1. Rename UTC calls: Replace hubble_utc_set() with hubble_time_set(). Rename the utc_time argument to initial_time in hubble_init() calls (position and type are unchanged).

Known Limitations

  • Satellite Network is pre-production: APIs and on-air protocol details may change in a future minor or patch release.

Compatibility

  • API compatibility: The BLE Terrestrial Network API is stable within the 2.x series. The Satellite Network API may receive breaking changes in a pre-production minor release before it is declared stable.

Testing

This release has been validated through:

  • Unit tests for BLE advertisement generation and encryption

  • Unit tests for EID generation in both counter source modes

  • Integration tests for the BLE Terrestrial Network module

  • Platform-specific CI builds: Zephyr (QEMU, native_sim), FreeRTOS (TI), ESP-IDF

  • Satellite packet encoding and frame-splitting tests

  • Ephemeris pass-prediction tests

Support