This a simple, experimental, not (well) tested, and incomplete decoder for radiosonde RS41 and DFM06/09 on a TTGO LoRa ESP32 with OLED display board.

There have been made some additions for TTGO LoRa ESP32 with only RST button. Please check also your OLED port settings, both versions use different ports. You can setup the depending ports in config.txt, OLED Setup is depending on hardware of LoRa board

• TTGO v1: SDA=4 SCL=15, RST=16
• TTGO v2: SDA=21 SCL=22, RST=16

You can use the button on the board (not the reset button, the second one) to issue some commands. The software distinguishes between several inputs:

• SHORT Short button press (<1.5 seconds)
• DOUBLE Short button press, followed by another button press within 0.5 seconds
• MID Medium-length button press (2-4 seconds)
• LONG Long button press (>5 seconds)

On startup, as well as after a LONG button press, the WiFI configuration will be started. The board will scan available WiFi networks, if the scan results contains a WiFi network configured with ID and Password in networks.txt, it will connect to that network in station mode. If no known network is found, or the connection does not suceed after 5 seconds, it instead starts in access point mode. In both cases, the ESP32's IP address will be shown in tiny letters in the bottom line. Then the board will switch to scanning mode.

In the scanning mode, the board will iterate over all channels configured in channels.txt, trying to decode a radio sonde on each channel for about 1 second for RS41, a bit less for DMF06/09. If a valid signal is found, the board switches to receiving mode on that channel. a SHORT buttong press will also switch to receiving mode.

In receiving mode, a single frequency will be decoded, and sonde info (ID, GPS coordinates, RSSI) will be displayed. The bar above the IP address indicates, for the last 18 frames, if reception was successfull (|) or failed (.) A DOUBLE press will switch to scanning mode. A SHORT press will switch to the next channel in channels.txt

A medium press will active scan the whole band (400..406 MHz) and display a spectrum diagram (each line == 50 kHz) For TTGO boards without configurable button there are some new parameter in config.txt:

• spectrum=10 // 0=off / 1-99 number of seconds to show spectrum after restart
• timer=1 // 0=off / 1= show spectrum countdown timer in spectrum display
• marker=1 // 0=off / 1= show channel edge freq in spectrum display

see Setup.md