Tasmota ESP32 BLE Sensor Gateway

Tasmota ESP32 BLE Sensor Gateway

Turn any ESP32 board into a Bluetooth Low Energy (BLE) sensor gateway with Tasmota. Passively scan for Xiaomi/Mijia, MiFlora, and other BLE sensors and bridge their data to MQTT — no pairing required for most devices.

Why This Project

• Bridge BLE to WiFi — BLE sensors have limited range, WiFi has unlimited reach via MQTT
• No hub needed — ESP32 acts as the BLE receiver directly
• Passive scanning — most sensors broadcast data openly, no pairing needed
• Multiple sensors — one ESP32 can receive from dozens of BLE devices
• Cheap BLE sensors — Xiaomi Mijia temperature sensors are $4-5 each

Supported BLE Sensors

Sensor	Model	Data	Encryption
Xiaomi Mijia Temp/Humidity	LYWSD03MMC	Temperature, humidity, battery	Requires bind key
Xiaomi MiFlora Plant Sensor	HHCCJCY01	Temp, humidity, light, soil moisture	Open
Xiaomi Mijia Temp/Humidity 2	LYWSD02	Temperature, humidity	Open
CGG1 Xiaomi Temp/Humidity	CGG1	Temperature, humidity, battery	Optional
MHO-C401 E-Ink Temp	MHO-C401	Temperature, humidity	Requires bind key
iBeacon devices	Various	UUID, RSSI (presence detection)	Open

Hardware Required

Component	Purpose	Est. Cost
Any ESP32 board	BLE receiver + WiFi transmitter	$4-8
Xiaomi LYWSD03MMC sensors	BLE temp/humidity broadcasters	$4-5 each

That's it — no additional hardware needed. The ESP32 has built-in BLE.

Tasmota Setup

1. Flash tasmota32.bin to any ESP32 board
2. Configure WiFi and MQTT
3. BLE scanning starts automatically

# Enable BLE (enabled by default on tasmota32)
SetOption115 1

# Show all discovered BLE devices
BLEDetails1

# Activate Mijia BLE driver
SO100 1

Encryption / Bind Keys

Some Xiaomi sensors encrypt their BLE broadcasts. You need to extract the "bind key":

Method 1: Custom Firmware (LYWSD03MMC)

Flash the sensor with ATC firmware to disable encryption and enable custom advertising format.

Method 2: Extract Bind Key

Use the Xiaomi Home app token extraction method to get the bind key, then configure in Tasmota:

# Set bind key for a specific sensor
BLEkey1 AABBCCDDEEFF00112233445566778899

JSON Output

{
  "BLE": {
    "LYWSD03MMC": {
      "mac": "A4:C1:38:XX:XX:XX",
      "Temperature": 22.3,
      "Humidity": 45.2,
      "Battery": 87,
      "RSSI": -65
    }
  }
}

Home Assistant Integration

BLE sensors auto-discover in Home Assistant via Tasmota MQTT:

• sensor.ble_lywsd03mmc_temperature
• sensor.ble_lywsd03mmc_humidity
• sensor.ble_lywsd03mmc_battery

Range and Placement

• BLE range: ~10m through walls, ~30m line of sight
• Place the ESP32 gateway centrally for best coverage
• Use multiple ESP32 gateways for large homes (each publishes to same MQTT broker)

Compatible Boards

• Any ESP32 board with built-in BLE (most do)
• ESP32-CAM — repurpose as BLE gateway
• Olimex ESP32-POE — wired Ethernet + BLE gateway (most reliable)
• M5Stack Atom Lite — tiny, plug it into USB anywhere
• ESP8266 + HM-10 module — alternative for non-ESP32 boards (limited)