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Version 0.9.0
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@cfr34k cfr34k released this 17 Jun 19:25
· 45 commits to main since this release
v0.9.0
b80b5c2

This release vastly improves the behaviour of this firmware on-air.

Improvements to the APRS Implementation

Special thanks in this area go to Thomas DL9SAU who provided provided ideas, suggestions and code to improve the APRS protocol implementation in this firmware.

The following changes have been made:

  • Handle further common frame types (such as positionless weather reports) as valid frames and show their info field in the RX comment area.
  • Keep the last known position of a station if a positionless frame was received from that station.
  • Airtime reduction:
    • Use “destination call digipeating”. Instead of the usual "WIDE1-1" in the path, SSID "-1" is set in the destination call field. This still allows digipeating while saving 6 bytes in every APRS transmission.
    • No digipeating is used for weather reports.
    • Do no longer transmit the APRS comment in every frame. The comment is transmitted at least once per hour or in every 10th position packet, whatever happens first. However, the minimum time between two comment transmissions is 10 minutes.
    • Position updates are now forced every 30 minutes (previously 15 minutes) to reduce the airtime impact of non-moving stations.
  • Use human readable version of the !DAO! field (format !W42! instead of !wnn!). As this firmware internally calculates in 32-bit floating point, position resolution is limited to 2.38m anyway. The new DAO variant’s resolution is 1.8 m (or better), so no precision is lost by this change.
  • Weather data is now compliant to the APRS specification and always includes the required c, s and g fields.
  • Send weather data in positionless weather reports. This completely separates weather data from position data and the previous toggling of the symbol between the selected one and the WX symbol is no longer necessary. Positionless weather report are inserted between the regular position updates every 5 minutes, if enabled.
  • Improved robustness during frame generation. If a field does not fit into the frame memory, it is dropped completely instead of truncating it. This prevents parser errors at the receiver.

Other Improvements

  • The compass displays now show a nice arrow instead of a simple line. This should make the direction easier to see.

Fixed Bugs

  • Fixed APRS RX history handling: while the RX list was not full, newly received packets were always appended to the list even if the station was heard before. This caused a single station to fill up the entire list.
Assets 4
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