Weather (WX) Telemetry

Our firmware can function as a simple APRS weather station (WX) by connecting a compatible external sensor via the I2C interface. When this feature is enabled, the device will periodically transmit weather data that can be viewed on APRS mapping services like aprs.fi.

The firmware automatically detects the connected sensor upon startup.

Supported Sensors

The device is compatible with a range of popular environmental sensors. Depending on the sensor used, different types of data can be transmitted.

Data Transmission

To ensure compatibility with the APRS network, weather data is handled in a specific way.

Alternating Packets

The device does not send weather data with every single beacon. Instead, it alternates between sending a standard beacon (containing telemetry like voltage in the comment) and a weather beacon. For example, the first beacon will be a standard position packet, the next will be a position packet with weather data, the third will be a standard one again, and so on.

APRS Symbol Change

This is a critical requirement for the APRS network. For weather data to be correctly parsed and displayed by APRS-IS servers, the station’s icon must be the official weather station symbol.

Our firmware handles this automatically. When a weather packet is due to be sent, the device temporarily changes its APRS symbol to the weather symbol (_, often displayed as a blue circle). Once the packet is sent, the symbol reverts to the one you configured for all subsequent non-weather beacons. Without this symbol change, most platforms will ignore the weather data.

Data Format

All weather data is encoded into the standard APRS format:

You can configure a temperature offset and an altitude correction in the web interface to ensure the most accurate readings.