Serial communication with TNC does not work

[phaethon]

I have built TNC on a breadboard (version with STM32L432KC). Uploaded firmware (firmware.bin) and tried to connect with tnc1-python-config. It allows to connect to device, the button Connect changes to Disconnect, but in the upper left corner it still says "Not connected" and all fields seem to be set to default values (e.g. TNC Information shows "Uknown" and "Unsupported").

Rebuilt firmware from source and started debugging with gdb. It seems to be initializing normally, then getting into a loop analyzing audio. I enabled define KISS_LOGGING and got some meaningful debug output on the serial console. This is the start of it:

�Mobilinkd Nucleo32 Breadboard TNC versi�CPU core clock: 48000000Hz��    Device UID: 0029004B 374B500C 2038325�Bootloader version: 0x10��Loading settings from EEPROM��Attempting to read 812 bytes from EEPRO�Hardware Settings (size=812):��TX Delay: 30��P* Persistence: 64��Slot Time: 10��TX Tail: 1��Duplex: 0��Modem Type: 1��TX Gain: 63��RX Gain: 0��TX Twist: 50��RX Twist: 0��Log Level: 0��Options: 16��MYCALL: NOCALL��Dedupe time (secs): 30��Aliases:��Beacons:��Checksum: 53ees��Setting output gain: 63 (log 0 + 1013)��Setting input gain: 0��enter readLevels��readLevels: start��exit readLevels��Vpp = 6, Vavg = 7114��Vmin = 7111, Vmax = 7117��DEMODULATOR��enter demodulatorTask��Acquired frame 0x20004514 (size after �Acquired frame 0x20004538 (size after �Acquired frame 0x2000455c (size after �FCS = e77e��CRC = f622�� 

Tried to place breakpoints in all serial port callbacks, but they don't fire neither using tnc1-python-config nor when connecting with serial console and trying to send keystrokes.

Operating system: Linux (Ubuntu 18.04 LTS)

Thanks in advance!

[mobilinkd]

Please use the Mobilinkd list at https://groups.io/g/mobilinkd for support with this TNC.