LE Coded is BLE's long-range mode. It exists to be heard from the next room. Put a phone in the kitchen and sdrtop 0.6.4 heard none of its advertisements. 0.6.5 hears 76 of 77.
The culprit sat under every packet
Every radio adds a DC offset at exactly the frequency it is tuned to. In NET that is exactly where every advertising packet sits. When the offset is stronger than a faint packet, the frequency the receiver reads falls apart, and no correction downstream can put it back together.
sdrtop now measures the radio's offset from the quiet stretches of the stream and takes it off before any receiver sees a sample.
| same recordings | 0.6.4 | 0.6.5 |
|---|---|---|
| LE Coded, phone in the kitchen | 0 | 76, down to -1.6 dB SNR |
| LE 1M packets through their CRC | 216 / 147 / 818 | 400 / 279 / 1220 |
Long range is long range again, and ordinary BLE hears up to twice as much. Accuracy was checked against the SIG-definition reference harness before anything shipped: unchanged.
SNR you can believe
The same phone, about 35 dB over the noise, used to read 13 to 21 dB at the tuned centre and 27 to 31 a few megahertz away. LE 1M stopped near 19. SNR is now the packet's power over the noise just before it, one way for LE 1M and LE Coded, and the phone reads 35 wherever it sits. A packet that arrives straight after another shows no SNR rather than a wrong one.
Also fixed
- A packet starting from silence could be measured a whole bit off.
- The decode-health tally now always adds up.
- Leaving the LE Coded view no longer leaves a "running" channel behind.
Under the hood: the NET worker's 1170-line loop is now 137, and CI checks every doc link.
cargo install sdrtop --lockedConfig and export columns unchanged. Full list in the
changelog.
Full Changelog: v0.6.4...v0.6.5