5 Frequently asked questions
sh123 edytuje tę stronę 2023-06-30 08:27:31 +03:00
  • Gaps in received audio, indicator often changes between RX/IDLE on the receiver side when sender and recipient are close by then
    • most likely you do not have enough bandwidth, use higher throughput modem mode, for LoRa modems you need approximately 100-150% of data rate for the given codec2 bitrate, AFSK1200 modems should work at 450 bps codec2 mode, 700 bps might work, but not on all modems, higher speed codec2 modes won't work on AFSK1200 for real time, need to enable KISS non-realtime buffering mode
    • modem goes into RX state too fast after sending first packet, increase TxTail parameter for your modem if it does not handle corresponding KISS command, so it will stay longer in TX before switching to RX
    • if you are using LibAPRS based modem, set TxTail and TxPreamble programatically by using APRS_setPreamble and APRS_setTail methods as it does not seem to set these values from CMD_TXDELAY and CMD_TXTAIL KISS commands
    • enable KISS buffering mode in Preferences, this will help with gaps at the cost of larger delay on receive before playback
  • Receiving audio on PC/Raspberry
    • For raw audio frames sudo cat /dev/ttyUSB0 | c2dec 700 - - | play -t raw -r 8000 -e signed-integer -b 16 -c 1 -
    • For KISS encapsulated audio frames command above could be used, but instead of cat use https://pypi.org/project/kiss/
  • App is not installed error when installing new application
    • Uninstall previous version and try to install again
  • Cannot install application from unknown source
    • You need to allow installation of apps from unknown sources from Android settings, or just install Android Studio and build-install
  • My USB modem is not detected
    • Run lsusb command and find your adapter vendor:product pair, run dmsg command and find lines modem detection log lines, create issue report with this information
  • Application keeps reconnecting to USB modem
    • Make sure Serial debugging is disabled in modem and serial USB is used only for data transfer
    • Make sure it works with empty sketch, where serial is initialized, but no data and logging transfers performed
    • Make sure modem serial boot log is disabled on platforms such as ESP32
  • APRS-IS only tracking
    • Select loopback TNC mdoem
    • Enable APRS from setttings
    • Enable APRS-IS from settings
    • Fill callsign, SSID, select APRS symbol
    • Go to Internet APRS and fill in APRS-IS passcode
    • Enable own APRS to APRS-IS