serin labs
CN105-to-Grove Cable
Assembled and tested, connecting the CN105 service port inside a Mitsubishi indoor unit to a Grove-style ESP32 board — the Serin Controller, an M5Stack Atom S3 Lite, or a NanoC6. No crimping, no soldering.
Secure checkout by Shopify, shipped from New Jersey. Etsy orders are handled by Etsy, under its purchase protection.
Before you buy
Does your unit have a CN105 port?
The cable plugs into the 5-pin CN105 header, standard on most Mitsubishi Electric wall units, ducted air handlers, and ceiling cassettes.
Which length
20 cm — wall-mounted mini-splits
The compact length lets the cable and the controller tuck away completely inside the empty space in the indoor unit's plastic housing. Nothing is visible once the front panel is back on.
50 cm — ducted and central air
Enough reach to mount the board outside the unit's metal chassis. SVZ, MVZ, PEAD and PVA air handlers have sheet-metal cabinets that weaken Wi-Fi; getting the board out of the box fixes it.
How it's made
Electrically tested
Every cable's power and communication wires are physically tested before it ships. A miswired or cold-crimped pin is the most common cause of a controller that never talks to the unit.
Braided and heat-shrunk
Orange PET braided sleeving with heat shrink at both ends, for abrasion resistance where the cable passes the sheet-metal edges inside the unit.
Correct connectors on both ends
A 5-way JST PAP-05V-S at the HVAC end and a 4-way Grove HY2.0 at the board end. Cavity 1 is left empty, so the unit's 12 V rail never reaches the board.
Shipped from New Jersey
Direct orders ship from the workshop, covered by the store policies. Four-packs clear the free US shipping threshold.
Works with
The cable interfaces with the internal CN105 5-pin header, standard on most Mitsubishi Electric models. On the board side it fits the Serin Controller and any Grove-equipped ESP32 — the M5Stack Atom S3 Lite and NanoC6 are the two listed boards.
It carries plain 5 V UART, so it works with the open-source firmware projects the community has built around this port:
- MitsubishiCN105ESPHome — Home Assistant, via ESPHome GitHub
-
mUART — the
mitsubishi_cn105ESPHome component GitHub - mitsubishi2MQTT — any MQTT broker GitHub
- SwiCago/HeatPump — the library the rest are built on GitHub
Serin Labs' own firmware builds for ESPHome and Apple Home are free, and the controller is flashable either way.
Build it yourself
Nothing here is proprietary. The wiring reference has the full pinout, the harness drawing, and the DigiKey part numbers for both connector housings — crimp your own and it works identically. This cable exists to save you the sourcing and the crimping, not to gatekeep anything.
Need the board too?
The Serin Controller ships with this cable attached
An ESP32-C6 with the CN105 cable already fitted and tested, from $35. Buy the cable on its own if you already have a Grove-equipped board.