In a previous post regarding the Weatherflow Tempest weather station and MQTT we created a Python script to listen to the Tempest UDP broadcast packets and send them to our MQTT broker for use with Openhab.
The new addition is also sending the data as APRS-IS packets. This step does require a ham license. A callsign and APRS-IS passcode are required. N5DUX has an online passcode creation tool.
The code is based on APRS-IS-WX. The APRS specification has two addendums – 1.1 and 1.2. Colin Cogle has several post and aprs-weather-submit that provided useful tidbits.
The code sends full weather packets with timestamp and location. A sample packet looks something like:
K8FJG-13>APRS,TCPIP*:@060142z4131.82N/08120.58W_081/001g002t037P...h97b09757Tempest
K8FJG is my callsign. the -13 is the appropriate SSID for a weather station. @ is the data type indicator for a position report with timestamp. 060142z is DDHHMM Zulu format timecode (refer to page 22 of the APRS spec). 4131.82N/08120.58W is my position. “_” is the symbol for weather report. 081/001g002 is wind direction, average speed and gust in mph. t037 is the temperature in Fahrenheit. P… is an empty rain value. h97 is the relative humidity. b09757 is the barometric pressure in hPa*10. Tempest is the weather station type.
The code sends to the Tier 2 APRS servers. In North America that means noam.aprs2.net on port 14580.
Once you are sending the proper data your station should appear on aprs.fi and using PinPoint.
For PC use with your radio look at DireWolf as a software TNC. Yet Another APRS Client is a solid PC client. Mobilinkd is a frequently recommended hardware TNC especially for mobile use with APRS-Droid. DigiRig makes several USB sound cards suitable for use with APRS and other digital modes.