serin labsLicenses & Compliance
This page covers two things about the hardware and firmware Serin Labs distributes: the licenses for the components every firmware installed by the browser flasher is built on, and the regulatory, safety, and trademark information for the Serin Controller. Everything is provided as-is; refer to each project or manufacturer for full terms.
The ESPHome and HomeKit-compatible builds are open source and their sources are linked below. The Matter-compatible build is free to install but is not published; the table for it lists the third-party components it is built on, which is the part these licenses govern.
ESPHome firmware
The ESPHome .bin images are compiled with the ESPHome toolchain on the ESP-IDF framework, together with the Mitsubishi CN105 component stack.
| Component | License | Source & license |
|---|---|---|
| ESPHome | MIT + GPLv3 | Source · License |
| MitsubishiCN105ESPHome (echavet) | None declared | Source |
| esphome-mitsubishiheatpump (geoffdavis) | BSD-2-Clause | Source · License |
| SwiCago/HeatPump | GPL-3.0 / LGPL-3.0 | Source · License |
| ESP-IDF (build framework) | Apache-2.0 | Source · License |
- ESPHome is dual-licensed: its Python tooling is MIT, and its C++/runtime code, compiled into the firmware, is GPLv3.
- SwiCago/HeatPump ships the GPL-3.0 license text in its repository, while its README states LGPL-3.0.
- MitsubishiCN105ESPHome does not include a license file.
- Corresponding source for the exact ESPHome build is published at Serin-Labs/serin-cn105.
HomeKit-compatible firmware
The HomeKit-compatible .bin images are built on Espressif's HomeKit SDK and the ESP-IDF framework.
| Component | License | Source & license |
|---|---|---|
| esp-homekit-sdk (Espressif) | ESPRESSIF MIT License; mu_srp under Apache-2.0 | Source · License · mu_srp |
| ESP-IDF | Apache-2.0 | Source · License |
Matter-compatible firmware
The Matter-compatible .bin images are built on Espressif’s esp-matter SDK, the Connectivity Standards Alliance’s Matter SDK (connectedhomeip) that it wraps, and the ESP-IDF framework. This build’s own source is not published; the components below are, and are what these licenses cover.
| Component | License | Source & license |
|---|---|---|
| esp-matter (Espressif) | Apache-2.0 | Source · License |
| Matter SDK (connectedhomeip) | Apache-2.0 | Source · License |
| ESP-IDF | Apache-2.0 | Source · License |
- The build is not Matter certified. It identifies itself with the SDK’s test attestation credentials rather than a certified device certificate, so every Matter controller warns about an uncertified accessory when it is added.
- Because those credentials are shared test values, every board flashed with a given build presents the same pairing code.
Flashing tool
The flash page runs entirely in your browser. It drives Espressif’s esptool-js to write the firmware over USB and the Improv Serial SDK to hand the board your Wi-Fi credentials afterwards; both are bundled with the page rather than loaded from a third-party server.
| Component | License | Source & license |
|---|---|---|
| esptool-js | Apache-2.0 | Source · License |
| Improv Wi-Fi Serial SDK (improv-wifi-serial-sdk) | Apache-2.0 | Source · License |
QR label scanner
The compatibility page’s label scanner runs entirely in your browser, using the open-source qr-scanner library to read the QR code on your unit’s nameplate. Photos and camera frames never leave your device.
Regulatory & compliance
The Serin Controller is a smart controller for Mitsubishi mini-splits that connects to the CN105 service port inside the indoor unit. It is available as a DIY parts list or as a pre-assembled kit, and is built from commercially available M5Stack development kits rather than custom radio hardware. The sections below collect the regulatory, safety, and trademark information that applies to it.
FCC compliance
Serin Labs does not manufacture or modify any radio hardware. Both supported boards are FCC-certified by their manufacturer, M5Stack Technology Co., Ltd., and M5Stack lists CE, MIC, and FCC certification for each on its product certifications page.
| Board | FCC ID | Certification |
|---|---|---|
| M5Stack NanoC6 | 2AN3WM5NANOC6 | Device certification held by M5Stack. Contains the Espressif ESP32‑C6‑MINI‑1 radio module, itself FCC-certified as 2AC7Z‑ESPC6MINI1. |
| M5Stack Atom S3 Lite | 2AN3WM5ATOMS3 | AtomS3-series device certification held by M5Stack. The radio is integrated in the ESP32‑S3 chip; the FCC ID appears on the regulatory label on your unit. |
These devices comply with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) the device may not cause harmful interference, and (2) the device must accept any interference received, including interference that may cause undesired operation.
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, try one or more of the following measures:
- Reorient or relocate the receiving antenna.
- Increase the separation between the equipment and receiver.
- Connect the equipment to an outlet on a circuit different from the one the receiver is connected to.
- Consult the dealer or an experienced radio/TV technician for help.
Caution: changes or modifications to the radio hardware not expressly approved by the party responsible for compliance could void your authority to operate the equipment. Flashing open-source firmware does not modify the radio circuitry.
Safety & installation
- Disconnect power first. Always switch off the mini-split at the breaker or disconnect before opening the indoor unit or connecting the controller.
- Low-voltage by design. The controller is powered by the CN105 port's 5 V supply and never connects to mains wiring.
- Mind the placement. The device installs inside the indoor unit; keep it and its cable clear of fan blades, heat exchanger fins, and the condensate tray, as shown in the wiring guide.
- Warranty. Connecting third-party accessories may affect your equipment warranty; check with your installer or Mitsubishi Electric if unsure.
- Not a safety device. The controller is a convenience accessory and must not be relied on as a safety, protection, or life-support device.
Trademarks & affiliations
Serin Labs is an independent open-source project. It is not affiliated with, endorsed by, or certified by Mitsubishi Electric Corporation, Apple Inc., or M5Stack Technology Co., Ltd.
- Mitsubishi Electric is a trademark of Mitsubishi Electric Corporation.
- Apple, Apple Home, HomeKit, Siri, HomePod, Apple TV, iPhone, and iPad are trademarks of Apple Inc., registered in the U.S. and other countries. The HomeKit-compatible firmware pairs with Apple Home using Apple's published HomeKit Accessory Protocol; the product is not MFi-certified and does not carry the “Works with Apple Home” badge.
- Matter is a trademark of the Connectivity Standards Alliance. The Matter-compatible firmware implements the Matter specification; it is not a certified Matter product, is not endorsed by the Alliance, and does not carry the “Works with Matter” badge.
- Home Assistant is a trademark of the Open Home Foundation. M5Stack is a trademark of M5Stack Technology Co., Ltd.
Materials & disposal
Like all electronics, the controller should not go in household trash at end of life. Take it to a local e-waste collection point; most US municipalities and many electronics retailers accept small electronics for recycling. Manufacturer compliance documentation for the boards is available from M5Stack.
DIY builds
If you source your own board and cable instead of buying the pre-assembled kit, regulatory compliance of those parts rests with their respective manufacturers. The boards above are the ones Serin Labs tests and recommends.
Contact
Questions about licenses, compliance, safety, or anything on this page: use the contact form, ask in Discord, or send a message to our Etsy shop.