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Reference · Terrestream Indoor Air Quality Sensor

Open-Source Software Notices

Effective June 1, 2026 · Version 1.0 · Operational reference; the Terms of Service control.

This page is the open-source attribution notice referenced by §3.5 of the Terms of Service. It identifies the third-party open-source software components incorporated in the firmware of the Terrestream Indoor Air Quality Sensor (the “ Device ”) at v4.0, together with the license under which each component is used. The Terms of Service control; this page is operational reference material only.

⚠️ Convenience-only reproduction; no warranty

The component identifications, license labels, and links provided on this page are reproduced from the upstream maintainers’ publications for User convenience only. Aerodyne Inc. does not author, control, or maintain the upstream license documents and makes no representation or warranty, express or implied, as to their accuracy, completeness, currency, or authenticity. The authoritative license text for each component is the LICENSE (or equivalent) file distributed by the upstream maintainer. The non-reliance, no-extrinsic-representation, and limitation-of-liability provisions of the Terms of Service (including, without limitation, §§ 7, 14, and 15) apply to this page in full.

Incorporated components (Device firmware v4.0)

Component Copyright holder Version License Upstream
ESP-IDF (Espressif IoT Development Framework) Espressif Systems (Shanghai) Co., Ltd. 5.5.4 Apache-2.0 github.com/espressif/esp-idf
FreeRTOS (bundled with ESP-IDF) Amazon Web Services / Real Time Engineers Ltd. (per ESP-IDF 5.5.4) MIT freertos.org
lwIP (bundled with ESP-IDF) Swedish Institute of Computer Science (SICS) and contributors (per ESP-IDF 5.5.4) BSD-3-Clause (modified) savannah.nongnu.org/projects/lwip
Mbed TLS (bundled with ESP-IDF) Arm Limited (per ESP-IDF 5.5.4) Apache-2.0 (elected from dual) github.com/Mbed-TLS/mbedtls
esp-dsp Espressif Systems (Shanghai) Co., Ltd. 1.6.0 Apache-2.0 github.com/espressif/esp-dsp
led_strip Espressif Systems (Shanghai) Co., Ltd. 3.0.1 Apache-2.0 components.espressif.com/components/espressif/led_strip
esp-nimble-cpp h2zero and contributors 2.5.0 Apache-2.0 github.com/h2zero/esp-nimble-cpp
littlefs (ESP-IDF component) Brian Pugh (component wrapper); ARM Limited and contributors (LittleFS core) 1.20.1 MIT (wrapper); BSD-3-Clause (LittleFS core) github.com/joltwallet/esp_littlefs
AceCommon Brian T. Park (as bundled at firmware v4.0) MIT github.com/bxparks/AceCommon
AceSorting Brian T. Park (as bundled at firmware v4.0) MIT github.com/bxparks/AceSorting
AceTime Brian T. Park (as bundled at firmware v4.0) MIT github.com/bxparks/AceTime
Adafruit BMP3XX Library Bosch Sensortec GmbH (original) · Adafruit Industries (Arduino port) (as bundled at firmware v4.0) BSD-3-Clause github.com/adafruit/Adafruit_BMP3XX
Adafruit BusIO Adafruit Industries (as bundled at firmware v4.0) MIT github.com/adafruit/Adafruit_BusIO
Adafruit Unified Sensor Adafruit Industries (as bundled at firmware v4.0) Apache-2.0 github.com/adafruit/Adafruit_Sensor
ArduinoJson Benoît Blanchon (as bundled at firmware v4.0) MIT github.com/bblanchon/ArduinoJson
LovyanGFX lovyan03 (Yuji Kuwabara) and contributors; Adafruit Industries (Adafruit_GFX-derived portions) (as bundled at firmware v4.0) FreeBSD (BSD-2-Clause) github.com/lovyan03/LovyanGFX
Sensirion Core (Arduino I²C core) Sensirion AG (as bundled at firmware v4.0) BSD-3-Clause github.com/Sensirion/arduino-core
Sensirion I²C SCD4x driver Sensirion AG (as bundled at firmware v4.0) BSD-3-Clause github.com/Sensirion/arduino-i2c-scd4x
Sensirion I²C SEN66 driver Sensirion AG (as bundled at firmware v4.0) BSD-3-Clause github.com/Sensirion/arduino-i2c-sen66

Per-firmware-version archives

The notices on this page describe the firmware version currently shipping. For every firmware release from v4.0.37 onward, a version-stamped archive of the same notices (this index.html plus the licenses/ subdirectory) is published alongside the firmware itself at api.terrestream.com. The archive is per-version, immutable, and cached at the edge for 24 hours.

Current firmware: v4.0.38 · download oss-notices-v4.0.38.tar.gz (approximately 40–50 KB).

URL pattern: https://api.terrestream.com/firmware/oss-notices-v<VERSION>.tar.gz. Substitute the firmware version You are running (for example, v4.0.37) to retrieve the archive for that exact release. Firmware versions earlier than v4.0.37 do not have a matching archive published; for those releases, this page is the canonical public reference.

Mbed TLS dual-license election

Mbed TLS is offered by its maintainer (Arm Limited) under a dual Apache License 2.0 OR GPL-2.0-or-later license; each recipient elects one of the two licenses for its use. Aerodyne elects the Apache-2.0 branch of that dual license for the firmware release identified on this page. The GPL-2.0-or-later branch is not invoked, and no GPL-2.0-or-later obligation (including source-code distribution under GPL-2.0 §3) applies to Aerodyne’s incorporation of Mbed TLS in the firmware. The full text of both license options is included in the upstream LICENSE file at github.com/Mbed-TLS/mbedtls/blob/main/LICENSE.

License texts

The full license text for each component is included with the component’s source distribution and may be obtained from the upstream URL identified in the components table above.

Canonical reference texts for the principal license families used in the Device firmware are available at:

Updates and version history

This page is republished with each firmware release that materially adds, removes, or upgrades an incorporated open-source component. Prior versions are preserved at /legal/archive.

  • June 1, 2026 · v1.0. Initial publication. Scope: Device firmware v4.0 only.

Cross-references

  • Terms of Service §3.5 — Open-Source Components clause; permissive-licenses-only commitment; license-conflict rule.
  • /legal/sensor-compliance — sensor BOM and vendor datasheets (component manufacturers are distinct from open-source contributors).