Sensor Wiring
BME280 Temperature & Humidity Sensor
The BME280 is a precise, low-power sensor that measures temperature, humidity, and barometric pressure. Perfect for monitoring hive environmental conditions.
Sensor Overview
Specifications
- Temperature Range: -40°C to +85°C
- Humidity Range: 0-100% RH
- Pressure Range: 300-1100 hPa
- Interface: I2C (0x76 or 0x77)
- Supply Voltage: 1.71V to 3.6V
- Current Consumption: ~2.7µA @ 1Hz
Key Features
- • High accuracy (±0.5°C, ±3% RH)
- • Low power consumption
- • 3-in-1 sensor (temp, humidity, pressure)
- • I2C interface for easy connection
- • Small footprint (2.5mm x 2.5mm)
- • Suitable for outdoor applications
Wiring Connection
ESP32/ESP8266 to BME280
BME280ESP32
VCC3.3V
GNDGND
SCLGPIO22
SDAGPIO21
Alternative ESP8266 Pins
BME280ESP8266
VCC3.3V
GNDGND
SCLD1 (GPIO5)
SDAD2 (GPIO4)
Important Wiring Notes
- • Never connect to 5V - BME280 is a 3.3V sensor
- • Use pull-up resistors (4.7kΩ) on SDA and SCL lines if experiencing communication issues
- • Default I2C address is 0x76, but some modules use 0x77
- • Keep wiring short (<20cm) for reliable I2C communication
- • For outdoor use, ensure proper weatherproofing of connections
ESPEasy Configuration
Step 1: Add Device
1. Go to the Devices tab in ESPEasy
2. Click Add for an empty device slot
3. Select Environment - BME280 from the device list
4. Configure the following settings:
Name:BME280_Hive
I2C Address:0x76 or 0x77
Altitude:Your location's altitude
Send to Controller:✓ Enabled
Step 2: Configure MQTT Topics
Set up your MQTT topics for ETWAN integration:
Temperature Topic:
etwan/hive/[HIVE_ID]/temperature
Humidity Topic:
etwan/hive/[HIVE_ID]/humidity
Pressure Topic:
etwan/hive/[HIVE_ID]/pressure
Troubleshooting
Sensor Not Detected
- • Check wiring connections, especially power and ground
- • Verify I2C address (try both 0x76 and 0x77)
- • Use I2C scanner to detect the sensor
- • Ensure 3.3V power supply (not 5V)
Inaccurate Readings
- • Allow 2-3 minutes for sensor stabilization after power-on
- • Protect sensor from direct sunlight and rain
- • Ensure good airflow around the sensor
- • Check for self-heating from nearby components
Optimal Placement
- • Mount in a ventilated weather shield
- • Position away from direct heat sources
- • Ensure representative airflow of hive environment
- • Keep sensor dry but allow air circulation
Next Steps
Once your BME280 is connected and configured, you can start monitoring your hive's environmental conditions in real-time through the ETWAN dashboard.