Mine is a carrier, and this is how i connected it.
I got a Midea Blanc split system, MSMAAU-07HRDN1. Integration works excellent in auto configuratuion mode. I'm not using additional IR functions, only main features available through UART. I'm having a problem with scenes. I have a set of settings I want to be applied to the unit by my automation. The settings are saved as scene and include power state (on, cooling) and temperature. When the scene is activated by scene.turn_on() , only power state is applied, the temperature doesn't change. If I re-apply the scene on the unit, that's already in desired cooling mode, the temperature is applied successfullty. It seems that the component (or my unit) has trouble changing power mode and temperature simultaneously.
The problem can be reproduced easily. Create two scenes: "T25" and "T20", only set different temperatures, don't change power and other settings. When applying each scene, the temperature in the climate entity changes according to saved values. Then set T25 power mode to "cooling" while keeping T20 mode "Off". Now when applying scenes only power mode changes, temperature does not. BUT when the device is off and you apply T25 scene once, it turns on without changing temperature, then you apply the same T25 scene again, it is aleady in desired power mode and applies temperature correctly.
I have another ESPHome Mitsubishi A/C integration, it works ok and applies all scene settings correctly by single operation. I guess this is a bug and I should post it somewhere on github, but haven't found where.
I am trying to integrate a SMLight SLWF-01 Pro into this board (Midea Klyma inverter MSEZ1B-12CRDN8) via the CN3 JST connector:
I tried a female USB-A to JST adapter first: when it was connected, the AC didn't even beep when mains power was turned on (beeps fine without the adapter).
I then soldered in Dupont cables onto the dongle for 5V, GND, TX0, RX0. With just 5V and GND connected, the AC would turn on with beep when mains powered.
Tried swapping RX/TX but never got a signal. Logs:
Logs excerpt:
Enqueuing the request...
18:29:31 [D] [ApplianceBase:075]
Getting and sending a request from the queue...
18:29:31 [D] [ApplianceBase:162]
TX: AA 21 AC 8D 00 00 00 00 00 03 41 81 00 FF 03 FF 00 02 00 00 00 00 00 00 00 00 00 00 00 00 03 22 A8 11
18:29:33 [D] [ApplianceBase:139]
Response timeout...
18:29:33 [D] [ApplianceBase:146]
Sending request again. Attempts left: 2...
18:29:33 [D] [ApplianceBase:162]
TX: AA 21 AC 8D 00 00 00 00 00 03 41 81 00 FF 03 FF 00 02 00 00 00 00 00 00 00 00 00 00 00 00 03 22 A8 11
18:29:35 [D] [ApplianceBase:139]
Response timeout...
18:29:35 [D] [ApplianceBase:146]
Sending request again. Attempts left: 1...
18:29:35 [D] [ApplianceBase:162]
TX: AA 21 AC 8D 00 00 00 00 00 03 41 81 00 FF 03 FF 00 02 00 00 00 00 00 00 00 00 00 00 00 00 03 22 A8 11
18:29:37 [D] [ApplianceBase:139]
Response timeout...
18:29:37 [D] [ApplianceBase:154]
Destroying the request...
18:29:37 [D] [AirConditioner:178]
Enqueuing a GET_STATUS(0x41) request...
18:29:37 [D] [ApplianceBase:173]
Enqueuing the request...
18:29:37 [D] [ApplianceBase:075]
Getting and sending a request from the queue...
18:29:37 [D] [ApplianceBase:162]
TX: AA 21 AC 8D 00 00 00 00 00 03 41 81 00 FF 03 FF 00 02 00 00 00 00 00 00 00 00 00 00 00 00 03 23 F6 C2
18:29:39 [D] [ApplianceBase:139]
Response timeout...
18:29:39 [D] [ApplianceBase:146]
Sending request again. Attempts left: 2...
18:29:39 [D] [ApplianceBase:162]
TX: AA 21 AC 8D 00 00 00 00 00 03 41 81 00 FF 03 FF 00 02 00 00 00 00 00 00 00 00 00 00 00 00 03 23 F6 C2
18:29:41 [D] [ApplianceBase:139]
Response timeout...
18:29:41 [D] [ApplianceBase:146]
Sending request again. Attempts left: 1...
18:29:41 [D] [ApplianceBase:162]
TX: AA 21 AC 8D 00 00 00 00 00 03 41 81 00 FF 03 FF 00 02 00 00 00 00 00 00 00 00 00 00 00 00 03 23 F6 C2
18:29:43 [D] [ApplianceBase:139]
Response timeout...
18:29:43 [D] [ApplianceBase:154]
Destroying the request...
Any leads?
Hi all,
I’m sharing a project that may be useful to people working on Midea-platform hydronic heat pumps and Home Assistant.
I published an ESPHome Modbus RTU package for my Mitsui-branded Midea-compatible heat pump:
This started as a local RS485/Modbus integration for my own setup. I cleaned it up, removed private data and published it so other users with similar Midea rebrands can compare registers, wiring and behavior instead of starting from zero.
My setup:
- Mitsui-branded Midea-platform hydronic heat pump
- RS485 Modbus RTU
- Waveshare ESP32-S3-RS485-CAN board
- ESPHome
- Home Assistant
- no cloud dependency
Current scope:
- runtime sensors
- diagnostic sensors
- configuration/status registers
- guarded write support for the validated water setpoint register
- ESPHome validation passing
- tested on real hardware
Important note: this is not advertised as a universal drop-in config for every Midea rebrand.
Other units such as Clivet, Riello, Immergas, Airwell, Hyundai, Mundoclima and similar Midea-platform heat pumps may share parts of the Modbus map, but I would strongly suggest starting read-only and validating every register against the wired controller / HMI before enabling writes.
The YAML is intentionally conservative. The only write I currently expose is the water setpoint register I validated on my own unit.
I’m interested in compatibility feedback from other owners:
- exact heat pump model
- RS485 terminals used
- baud rate / parity / slave address
- registers that match
- registers that differ
- whether values match the wired controller
- any errors caused by polling too much or reading larger register ranges
The goal is not to bypass safety logic or replace the manufacturer controller. The goal is to expose useful local data to Home Assistant and make these heat pumps easier to integrate into energy dashboards, PV surplus logic, monitoring and automations.
Hi, today i installed my ESP and it is working!
Im using this device: https://www.waveshare.com/wiki/ESP32-S3-RS485-CAN?srsltid=AfmBOop74rEMeA9cKX1WB3SFDPUynEqcCBhiEOo1_9PnYUAP5kSCazAV
the script is similar to the one you use. I connected only XY to the RS485 pins and powered the waveshare via USB-C
Has anyone worked around disconnect issues with the slwf-pro dongle ? I don’t think it’s WiFi related, since I’ve done all the usual recommendations. I also did a custom esphome config to turn off the web interface and disable power saving (which may have already been disabled by default anyway),
To get the dongle plugged into the USB or on the AC, I did scissor off the plastic sides and put a new but metal connector on. My next idea is to solder on a USB cable directly to the adapter on the AC.
Hi,
i have a very similar board on my midea wallmounted (its an Bosch branded). I am also looking to find the IR-diode to connect, there is something beloiw the small digit of the display, but it has 4 pins… have you found something to connect to?