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Tweak reported timestamps so that the relative timing of Mode S and

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Mode A/C messages is the same as from a Beast/Radarcape.
This commit is contained in:
Oliver Jowett 2017-01-15 19:29:25 +00:00
parent 58e227897b
commit 72e786af35
1 changed files with 9 additions and 2 deletions
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11
demod_2400.c
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@ -304,7 +304,11 @@ void demodulate2400(struct mag_buf *mag)
// Set initial mm structure details
mm = zeroMessage;
mm.timestampMsg = mag->sampleTimestamp + (j*5) + bestphase;
// For consistency with how the Beast / Radarcape does it,
// we report the timestamp at the end of bit 56 (even if
// the frame is a 112-bit frame)
mm.timestampMsg = mag->sampleTimestamp + j*5 + (8 + 56) * 12 + bestphase;
// compute message receive time as block-start-time + difference in the 12MHz clock
mm.sysTimestampMsg = mag->sysTimestamp; // start of block time
@ -637,8 +641,11 @@ void demodulate2400AC(struct mag_buf *mag)
// This message looks good, submit it
// For consistency with how the Beast / Radarcape does it,
// we report the timestamp at the second framing pulse (F2)
mm.timestampMsg = mag->sampleTimestamp + f2_clock / 5; // 60MHz -> 12MHz
// compute message receive time as block-start-time + difference in the 12MHz clock
mm.timestampMsg = mag->sampleTimestamp + f1_clock / 5; // 60MHz -> 12MHz
mm.sysTimestampMsg = mag->sysTimestamp; // start of block time
mm.sysTimestampMsg.tv_nsec += receiveclock_ns_elapsed(mag->sampleTimestamp, mm.timestampMsg);
normalize_timespec(&mm.sysTimestampMsg);