How to Flash ESPHome Firmware onto the Xiaomi Mi Smart Antibacterial Humidifier – A Complete Guide

Why the Xiaomi Mi Smart Antibacterial Humidifier Matters

The Xiaomi Mi Smart Antibacterial Humidifier has become a staple in modern smart homes because of its sleek design, built‑in UV sterilization, and native Wi‑Fi connectivity. However, the device is locked into Xiaomi’s proprietary cloud, which means you must rely on their servers for every status update, schedule change, or firmware upgrade. For DIY enthusiasts and privacy‑conscious homeowners, this creates two major pain points:

• Vendor lock‑in that can render the device useless if the cloud service is discontinued.
• Unnecessary data transmission of humidity levels, usage patterns, and even room occupancy.

By replacing the stock firmware with an open‑source alternative, you gain full control, eliminate third‑party data collection, and unlock powerful automation possibilities through Workflow automation studio.

Step‑by‑Step Guide: From Stock to Open‑Source

1. Gather Tools & Materials

• Soldering iron with fine tip
• 0.1 mm² stranded wire
• USB‑to‑UART 3.3 V adapter (FTDI or CP2102)
• Phillips #00 screwdriver
• Heat‑shrink tubing or electrical tape
• Computer with Python 3 and esptool.py installed

2. Identify the Correct Model

Verify the internal model number printed on the PCB: deerma.humidifier.jsq. If the label reads anything else, the ESPHome component may not match, and you could brick the device.

3. Disassemble the Humidifier

Follow these precise actions to avoid damaging the water‑proof seal:

1. Unplug the power cord and remove the water tank.
2. Peel back the rubber foot ring; it hides four Philips screws.
3. Unscrew the four hidden screws and gently lift the top cover.
4. Locate the ESP‑WROOM‑02 module attached to the back of the housing.

4. Wire the ESP8266 for Flashing

Solder the wires as shown in the original diagram (colors are critical):

• Orange – GND
• Grey – VCC (3.3 V)
• Yellow – GPIO0 (flash mode)
• Brown – RX
• Red – TX

Connect the FTDI adapter: GND ↔ GND, VCC ↔ 3.3 V, TX ↔ RX, RX ↔ TX. Tie GPIO0 to GND before powering the module to trigger flash mode.

5. Backup the Original Firmware

Open a terminal and run:

esptool.py --chip esp8266 --port /dev/ttyUSB0 --baud 230400 \\
  read_flash 0x0 0x200000 xiaomi-original.bin

Storing this file lets you restore the stock firmware if you ever need to revert.

6. Build & Flash ESPHome Firmware

Create a simple humidifier.yaml configuration using the community component available on GitHub. A minimal example:

esphome:
  name: xiaomi_humidifier
  platform: ESP8266
  board: esp01_1m

wifi:
  ssid: "YOUR_SSID"
  password: "YOUR_PASSWORD"

uart:
  tx_pin: GPIO1
  rx_pin: GPIO3
  baud_rate: 9600

# Include the custom component
external_components:
  - source: github://stv0g/esphome-config/components/xiaomi_deerma_humidifier

xiaomi_deerma_humidifier:
  id: humidifier
  uart_id: uart_bus

output:
  - platform: gpio
    pin: GPIO2
    id: led

binary_sensor:
  - platform: status
    name: "Humidifier Status"

Compile and upload with:

esphome humidifier.yaml run

7. Verify Integration with Home Assistant

Once the device boots, it will announce itself via mDNS. Add the following to your configuration.yaml:

esphome:
  name: xiaomi_humidifier
  platform: ESP8266
  board: esp01_1m

# No cloud, no extra credentials needed – everything runs locally.

8. Re‑assemble the Humidifier

Carefully route the wires back through the rubber foot ring, replace the cover, and secure the screws. Ensure no stray solder bridges touch the water tank area.

🎉 Your Xiaomi humidifier is now a cloud‑free, locally controlled smart device!

Practical Tips & Safety Warnings

Safety First

• Always disconnect the power before opening the unit.
• Work in a dry environment; moisture and electronics do not mix.
• Double‑check polarity on the VCC line – feeding 5 V will destroy the ESP8266.
• Use heat‑shrink tubing on all solder joints to prevent short circuits.

Tips for a Smooth Flash

• Set the FTDI adapter to 3.3 V mode; many adapters default to 5 V.
• If flashing fails, try lowering the baud rate to 115200.
• Keep the humidifier’s firmware backup in a safe folder; you may need it for warranty claims.
• After flashing, give the device a few minutes to stabilize before adding it to Home Assistant.

Read the original source here.

Related reads:
Smart Home Firmware Updates,
ESPHome Integration Guide.