Control and monitor a myCOOLMAN MCMR portable fridge/freezer over Bluetooth LE from Home Assistant — using your existing ESPHome Bluetooth Proxy, no dedicated ESP needed. Confirmed working on the single-zone MCMR43; the single-zone MCMR60 should also work via the same protocol (untested). Dual-zone models — MCMR38DZ, MCMR55DZ, MCMR78DZ — are untested and expose extra freezer fields this integration does not yet use.
The protocol was reverse-engineered from the myCOOLMAN Recreation Android app (github.com/luoxs/Mycoolman). No cloud, no account — everything is local.
| Entity | Type | Notes |
|---|---|---|
| Temperature | sensor | Cabinet temperature (°C) |
| Setpoint | sensor + number | Read-back and control |
| Input voltage | sensor | Scaling is a best guess — verify (see below) |
| Error code | sensor | Raw status/error byte |
| Power | switch | On/off |
| Turbo | switch / binary_sensor | Turbo mode |
| Battery protection | select | Low / Medium / High |
| Pairing OK | binary_sensor | Reflects the fridge's PIN-valid flag |
| LED | select | High White / Low White / Orange (write-only) |
| Buzzer | switch | Write-only |
| Auto-dim | switch | Display auto-dim, write-only |
- Home Assistant with the Bluetooth integration set up.
- A Bluetooth adapter or an ESPHome Bluetooth Proxy with active connections (the default proxy build). The fridge uses one of the ESP32's 3 active connection slots.
- Your fridge's 3-digit pairing PIN (shown on the fridge display during pairing; if you've lost it, remove the fridge in the official app or clear the app's storage to make it display again).
- HACS → three-dot menu → Custom repositories.
- Add this repository's URL, category Integration.
- Install myCOOLMAN MCMR Fridge/Freezer, then restart Home Assistant.
- The fridge should be auto-discovered under Settings → Devices & Services. Otherwise add it manually via + Add Integration → myCOOLMAN MCMR Fridge/Freezer.
- Enter the 3-digit PIN when prompted, then set the fridge's setpoint range (defaults to −20…20 °C, confirmed for the single-zone MCMR43 — adjust if your model differs).
Bytes 12–13 of the status frame are assumed to be voltage in tenths of a volt.
Compare the "Input voltage" sensor against the fridge's own display; if it's off
by a constant factor, adjust the divisor in protocol.py (parse_status).
- MCMR60 / dual-zone owners — if you can install this and report back (or open an issue) with what works and what doesn't, that would help a lot; only a single-zone MCMR43 has been tested against so far.
- Input voltage scaling — see Verifying the voltage scaling above; a multimeter reading at the DC input barrel plug compared against the sensor would confirm or correct the divisor.
- Bugs, feature ideas, or other models — issues and PRs are welcome on the repo.
- The integration holds a persistent connection (for push updates), so it occupies one proxy connection slot continuously.
- The fridge must stay within range of a proxy/adapter.
- Setpoint range defaults to −20…20 °C (confirmed for the single-zone MCMR43). Set it during setup, or change it later via Settings → Devices & Services → myCOOLMAN MCMR Fridge/Freezer → Configure.
Unofficial, not affiliated with or endorsed by myCOOLMAN. Use at your own risk.
This integration was built with the assistance of Claude (Anthropic's AI coding assistant) — the author is an enthusiast, not a professional programmer. Review the code yourself before relying on it, especially around Bluetooth connection handling.
The BLE protocol was learned by observing and analyzing the behavior of the myCOOLMAN Recreation Android app (github.com/luoxs/Mycoolman) as a reference; no source code from that project is included here. That project's repository does not clearly state a license, so if you plan to reuse protocol details beyond what's documented in this README, verify your own rights to do so independently.
MIT — see LICENSE.