Control Chihiros aquarium devices from Home Assistant via ESPHome (BLE bridge, no cloud, no app)

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1

I replaced the Chihiros app entirely with an ESP32-S3 running ESPHome. All devices are exposed to Home Assistant as native entities — no cloud, no phone required.

Supported devices

  • CO2 Controller — Working :white_check_mark:

  • Magnetic Stirrer (4-channel) — Working :white_check_mark:

  • Cooling Fan — Working :white_check_mark:

  • Doctor Mate (TDS/EC meter) — Working :white_check_mark:

  • WRGB II light — Working :white_check_mark:

  • Dosing Pump — Working :white_check_mark:

How it works

All Chihiros devices use the Nordic UART Service (NUS) over BLE. Connections are non-persistent by design: the ESP32 connects, sends commands, then disconnects. Most devices store their schedule on an internal RTC, so you only reconnect when something changes.

A shared chihiros_ble.h header handles the full protocol — framing, CRC, sequence numbers, RTC sync, and per-device command sets. The YAML configs use this as a local ESPHome external component.

The protocol was reverse-engineered from Bluetooth HCI btsnoop logs captured with a rooted Android phone.

Frame format:


[header] [0x01] [len] [0x00] [seq] [cmd] [data...] [XOR-CRC]

What you get in Home Assistant

  • CO2: schedule tied to photoperiod with configurable pre-start offset

  • Stirrer: 4 channels on/off, speed sliders, interval timer, per-channel enable

  • Cooling fan: start/max temperature thresholds, silent mode toggle, live water temp + room temp + humidity sensors

  • Doctor Mate: TDS target (Plant/Fish/Shrimp presets or manual), tank volume, live EC sensor

  • WRGB2: auto schedule (RGB + ramp time + photoperiod) or manual brightness sliders per channel

  • Dosing pump: 3 pumps, per-pump weekly schedule (day/time/volume), manual dose button

Hardware

  • ESP32-S3-N16R8

  • Powered by USB or 5V

BLE 5.0 required — Chihiros devices use BLE 5.0 extended advertising, which is invisible to BLE 4.x hardware. A classic ESP32 will not detect them at all. The S3 is also recommended for its extra RAM when running the BLE scanner alongside multiple client connections.

GitHub: GitHub - BartdeJonge/chihiros-esphome · GitHub

Happy to answer questions about the protocol details. If you have a Chihiros device not on the list, I can help figure out the frames with btsnoop logs.

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You mention “3 pumps” in the dosing pump section. Does this mean it’s not the Dosing Mate pumps that come in either 2 or 4 pump configurations that have been setup?

The manual dose button would be very helpful for my auto water change setup to dose fertilisers after a water change. I have a 2 head Dosing Mate where you have to set a manual dose amount before dosing.

3

Cool.
I own a WRGB2 lamp and many spare ESPs.
Is it possible to edit the light schedule on the lamp?

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I got the config running on a xiao S3 board :wink:
and will test some more

5

dude this is so awesome! i was basically searching for that for over a year :smiley:

I did some improvements on your implementation, maybe you (and someone else) may find it useful: GitHub - d1rty-pixel/chihiros-ble-proxy: ESPHome / Chihiros BLE Proxy · GitHub

it still has some quirks, but I'll update this the next days

cheers, and thanks again!

6

Amazing! Thank you for this. I have managed to connect both my dosing mate 2-head dosing pumps and have them auto-dose after water changes.