EDU0157-EN Lark Weather Station Reference: API, Protocol & Pinout

Library

Arduino/Raspberry Pi: DFRobot_LarkWeatherStation
UNIHIKER: Lark Weather Station Library
micro:bit/Makecode: pxt-DFRobot_lark

Communication Protocol Description

Communication Modes: I2C (default) or UART.
UART Configuration: Baud rate fixed at 115200.
I2C Address: Default address is 0x42.

API Description

Function	Description
`DFRobot_LarkWeatherStation_I2C(addr, &Wire)`	Initialize I2C communication with the specified device address.
`atm.begin()`	Initialize the Lark Weather Station. Returns `0` on success.
`atm.getTimeStamp()`	Get the current time stamp (YYYY-MM-DD HH:MM:SS).
`atm.getValue("Parameter")`	Get the value of a specified parameter (e.g., "Speed", "Temp", "O2").
`atm.getUnit("Parameter")`	Get the unit of a specified parameter (e.g., "m/s", "℃", "%vol").
`yunque_i2c.set_local_time()`	Synchronize UNIHIKER’s system time with the Lark Weather Station (Python).

MakeCode Block Module Description

Lark Initialization: Initializes communication with the Lark Weather Station.
Get Weather Data: Select a physical quantity (e.g., wind speed, temperature) from the dropdown menu to retrieve its value.
Display Data: Use micro:bit’s LED matrix to display the retrieved weather data.

Principle

The Lark Weather Station integrates high-quality sensors to measure wind speed (anemometer), wind direction (wind vane), temperature, humidity, and air pressure (combined sensor). Data is transmitted via I2C/UART and can be stored locally (16M USB disk) or processed by external controllers.

Other Supplementary Information

Parameter Configuration

Connect the Lark Weather Station to a computer via Type-C to modify the config file. Configurable parameters include:

Communication: I2C/UART (default: I2C)
Sample_rate: Data sampling rate (1-60S or 1-60M, default: 30S)
Record: Enable/disable data recording (ON/OFF, default: ON)
Delay_record: Delay before first data recording (10~60S, default: 10S)
Light_Switch: Enable/disable RGB light (ON/OFF, default: OFF)
Low_Power: Enable/disable low-power mode (ON/OFF, default: OFF)

Changes take effect after a reboot.

Firmware Upgrade

Back up data from the Lark Weather Station’s USB drive.
Press the firmware upgrade button (located at the bottom) and connect to a computer.
Drag the latest .uf2 firmware file to the "RPI-RP2" USB drive.

Download Firmware

Low Power Mode

Enabled by setting Low_Power:ON.
Disables I2C/UART communication.
Minimum sampling rate: 60 seconds.
Wakes up to record data when the wind vane detects motion.

RGB Indicator Lights

Yellow: System initializing (≈1 second).
Red: System anomaly (e.g., invalid config).
Green: I2C communication mode.
Blue: UART communication mode.
Flashing Green/Blue: Data is being stored.

System Time Setting

Via Config File: Add Time:YYYY/MM/DD/HH:MM:SS to the config file (e.g., Time:2023/07/24/17:56:15).
Via Code: Use atm.setTime(YYYY, MM, DD, HH, MM, SS) (Arduino) or yunque_i2c.set_local_time() (UNIHIKER).

Sensor Expansion

The Lark Weather Station supports two Gravity I2C expansion interfaces. To expand sensors:

Remove the bottom screws and open the expansion bay.
Connect additional sensors (e.g., oxygen, ozone, PM2.5).
Reassemble the weather station.

Expandable Sensors:

SKU	Sensor	Physical Quantity	Name Tag
SEN0228	Ambient Light Sensor	Ambient Light	Light
SEN0322	Oxygen Sensor	Oxygen Concentration	O2
SEN0321	Ozone Sensor	Ozone Concentration	O3
SEN0460	PM2.5 Sensor	PM1.0/PM2.5/PM10	PM2.5

Data Acquisition Example (Oxygen Sensor SEN0322):

Serial.print(atm.getValue("O2"));
Serial.println(atm.getUnit("O2"));

Reference