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Wiring Reference: CN105 to Grove

Pinout and wiring reference for connecting an M5Stack Atom S3, S3 Lite, or NanoC6 to a Mitsubishi heat pump CN105 port.

Wiring Diagram

CN105 to Grove Wiring Diagram Wiring diagram showing connections between the CN105 5-pin JST connector on a Mitsubishi HVAC unit and the 4-pin Grove HY2.0 connector on an ESP32 controller. Black wire: GND to GND. Red wire: 5V to 5V. White wire: CN105 TX to Grove RX (GPIO 2). Yellow wire: CN105 RX to Grove TX (GPIO 1). CN105 (HVAC Side) Pin 1 Pin 1 · 12V not used Pin 2 · GND Pin 3 · 5V Pin 4 · TX Pin 5 · RX JST-PAP-05V-S Grove (Device Side) Pin 1 Pin 1 · GND Pin 2 · 5V Pin 3 · RX Pin 4 · TX HY2.0-4P (Grove) Black Red White Yellow Ground Power HVAC TX → ESP RX ESP TX → HVAC RX

Connectors

JST PAP-05V-S connector (5-pin white housing) on left and HY2.0-4P Grove connector (4-pin white housing) on right

Connection Reference

Wire CN105 Pin Signal Grove Pin Signal
Black Pin 2 GND Pin 1 GND
Red Pin 3 5V Pin 2 5V
White Pin 4 TX Pin 3 RX (GPIO 2)
Yellow Pin 5 RX Pin 4 TX (GPIO 1)

Cable Options

You may use the information above to build your own cable using these parts:

Pre-assembled cables coming soon. For a complete shopping list including boards, see the parts list.

Detailed Pinout Reference

CN105 (JST-PAP-05V-S) Pinout

Pin Signal Description
112VNot used
2GNDGround
35V5V Power
4TXData output from HVAC (5V logic)
5RXData input to HVAC (5V logic)

Grove (HY2.0-4P) Pinout for M5Stack Atom S3, S3 Lite, and NanoC6

Pin Signal Description
1GGround (connects to ESP32 GND)
25V5V Power (connects to ESP32 5V/VCC)
3G2RX (connects to ESP32 UART RX pin)
4G1TX (connects to ESP32 UART TX pin)

References

Disclaimer

Always turn off power to your HVAC unit before connecting or disconnecting any cables. This reference is provided as-is. Wiring is at your own risk.