DFRobot - Gravity: Tipping Bucket Rainfall Sensor - I2C & UART

This Gravity tipping bucket rainfall sensor turns collected rain into rainfall measurements for a weather station, environmental monitoring project or smart farm. With 0.28mm resolution, this rain gauge provides rainfall values in millimeters alongside system operating time. I2C and UART outputs support integration with micro:bit, Arduino, ESP32 and Raspberry Pi, while the Gravity interface and ready-to-use libraries simplify setup. The kit combines a tipping bucket collector with a separate signal adapter, giving a project both the rain-collection mechanism and the digital interface needed to read measurements.

Rainfall Amount in Millimeters, with 0.28mm Resolution

This tipping bucket rain gauge measures accumulated rain through a repeating mechanical action. Collected water flows through a funnel into the bucket; once enough water accumulates, the bucket tips and generates a pulse. Counting these events produces a rainfall amount rather than just an indication that rain is present. A specified 0.28mm resolution supports rainfall logging, while system operating time provides additional context for the running sensor. Resolution describes the measurement increment, not a stated accuracy guarantee.

Self-Draining Collector with No Internal Electronics

This rainfall sensor's tipping bucket collector contains no electronic components and uses a hollow bottom to let collected rainwater drain automatically. The collector receives rain and releases the measured water as the bucket operates, supporting repeated collection during rainfall. Signal processing is handled by the separate adapter board. This arrangement keeps the collection mechanism distinct from the powered interface, with an important installation requirement: the signal adapter is not waterproof and must be protected from rain.

I2C or UART for Flexible Project Integration

This Gravity rainfall sensor offers two digital output options, allowing an I2C or UART connection to match the controller and available ports. A 3.3 to 5.5V DC supply range and working current below 3mA support integration into low-current sensing projects. The supplied Gravity-4P connector and ready-to-use libraries help bring up measurements without developing the sensor interface from scratch. Compatible platforms include micro:bit, Arduino, ESP32 and Raspberry Pi, making this rain gauge suitable for both classroom builds and maker monitoring systems.

Note: The signal adapter board is not waterproof. Do not expose the signal adapter board to rain.

Wiring Diagram of Gravity: Tipping Bucket Rainfall Sensor and Arduino Uno

If you want to know the principle of the rain gauge, please click here to read more.

• Rainfall values in millimeters and system operating time
• 0.28mm rainfall resolution using a tipping bucket mechanism
• No electronic components inside the tipping bucket collector
• Hollow bottom for automatic rainwater drainage
• I2C and UART digital outputs
• Compatible with micro:bit, Arduino, ESP32 and Raspberry Pi
• Gravity interface and ready-to-use libraries for simpler integration

• Weather monitoring
• Environmental monitoring
• Smart farming
• Research and education

• Working Voltage: 3.3 to 5.5V DC
• Working Current: ＜3mA
• Output Signal: I2C/UART
• Resolution: 0.28mm
• Operating Temperature: -40 to 85°C
• PCB Size: 32mm x 37mm/1.26 x 1.46 inches
• Tipping Bucket Size: 118mm*59mm*80mm/4.65 x 2.32 x 3.15inches
• Mounting Hole Size: 3.1mm
• Weight: 119g (Tipping bucket), 5.3g (PCB)

• Gravity: Tipping Bucket rainfall Sensor x1
• Signal Adapter x1
• Gravity-4P I2C/UART Sensor Connector x1