TrovaLaSondaFw

What's this?

A firmware for the Heltec Wifi LoRa32 V3 and LilyGo TTGO LoRa32 V2.1_1.6 boards (433MHz version only). Its purpose is receiving meteorological radiosondes. To be used in conjunction with your phone and the Trova La Sonda app for Android. Be sure to select "Bluetooth Low Energy" to connect to the device.

Is it free?

Absolutely. A donation to a charity would be much appreciated as a way to say thanks. I especially recommend the Landmine Relief Fund.

Is it open source?

Definitely. See the code on github.

Did you do all this alone?

We all stand on the shoulders of giants. Part of the decoding code is taken from sondedump, the RS decoders and the rdz_ttgo_sonde firmware. This page was made possible by esp-web-tools.

Is it stable?

As of today (April 11, 2026) it has undergone quite some testing, mostly by me. But beware if you rely solely on this solution to locate sondes in the wild...

Which kind of radiosondes can it receive/decode?

Model Tested in the lab Tested in the wild
Vaisala RS41 yes yes
Vaisala RS41+AUX yes yes
Meteomodem M10 yes no
Meteomodem M20 yes yes
Graw DFM-09 yes no
Graw DFM-17 yes no

Installation

Connect your board to your PC with an USB cable and click this button:


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