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. This page collects 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.

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.
• 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 we test and recommend.

Open-source firmware

The firmware distributed through the browser flasher is open source. See the Licenses & Source page for each component's source code and license terms.

Contact

Questions about compliance, safety, or anything on this page: reach us through the support page, GitHub Discussions, or a message to our Etsy shop.