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  1. 30 Nov, 2020 1 commit
  3. 29 Nov, 2020 4 commits
  5. 28 Nov, 2020 7 commits
  7. 27 Nov, 2020 1 commit
    • Manolis Surligas's avatar
      AX.25: Fix back-to-back frames decoding · 5d07acfc
      Manolis Surligas authored 
      The AX.25 specification, dictates that two concecutive frames
may share the same AX.25 SYNC flag as stop and start indicator.
This commit deals with this issue allowing such frames to be decoded

In addition, this commit adds some extra checks to quite the decoding
state early and avoid possible invalid frames to pass the weak CRC
check.
Signed-off-by: Manolis Surligas's avatarManolis Surligas <surligas@gmail.com>
      5d07acfc
  9. 25 Nov, 2020 2 commits
    • Manolis Surligas's avatar
      AX.25: Correct up to 1 error bit · 9b19f840
      Manolis Surligas authored 
      Signed-off-by: Manolis Surligas's avatarManolis Surligas <surligas@gmail.com>
      9b19f840
    • Manolis Surligas's avatar
      Fix decoding issue of AX.25 decoder · c56167dd
      Manolis Surligas authored 
      The AX.25 decoder had two major issues. The first one is related
with bit stuffing and originates from a rollback. Previously, the
decoder requested at least two repetitions of the AX.25 flag. To do
this, a 16-bit sift register was used. During a rollback an erroneous
bit shift during a stuffed bit was left over.

The other issue was at the FSM. When the frame end AX.25 flag was
received, the decoder did not exit properly if the CRC was false.
The decoder continously tried to match the CRC of an invalid frame
until the maximum frame size was reached. This was the source of
many invalid frames. The weird byte patterns that may appeared
was actually the random init values of the frame buffer.
Signed-off-by: Manolis Surligas's avatarManolis Surligas <surligas@gmail.com>
      c56167dd
  11. 24 Nov, 2020 1 commit
  13. 22 Oct, 2020 1 commit
  15. 21 Oct, 2020 1 commit
  17. 16 Oct, 2020 1 commit
  19. 05 Oct, 2020 1 commit
  21. 01 Oct, 2020 1 commit
  23. 29 Sep, 2020 2 commits
  25. 25 Sep, 2020 2 commits
  27. 29 Jul, 2020 1 commit
  29. 21 Jul, 2020 3 commits
  31. 11 Jun, 2020 2 commits
  33. 06 Jun, 2020 3 commits
  35. 08 May, 2020 2 commits
  37. 06 May, 2020 1 commit
  39. 10 Apr, 2020 1 commit
  41. 09 Apr, 2020 1 commit
    • Manolis Surligas's avatar
      AX.100 Mode 6: Make available the AX.25 header too · e5b978dc
      Manolis Surligas authored 
      Until now, the Mode 6 decoder produced only the RS codeblock,
becasue both the RS and the CRC32-C ensuring the validity of
the frame. However, the AX.25 header holds vital information
that can be used to descriminate between nearby spacecrafts
using the same modem. Now the decoder also makes available
this headder, but users should take into consideration that
errors may exists on these data.

Many will argue that the AX.25 CRC could be used too, but
this defeats the purpose of using a FEC.
Signed-off-by: Manolis Surligas's avatarManolis Surligas <surligas@gmail.com>
      e5b978dc
  43. 08 Apr, 2020 1 commit