diff --git a/help.md b/help.md deleted file mode 100644 index 5290be65a..000000000 --- a/help.md +++ /dev/null @@ -1,79 +0,0 @@ -A word about the `-symbollength` flag: - -`symbollength` sets the symbol length in samples. Defaults to 72. - -Sample rate is determined by this value as follows: - -``` -DataRate = 32768 -SampleRate = SymbolLength * DataRate -``` - -Sample rates are limited by the dongle such that: - -``` -225 kHz < Sample Rate < 300 kHz and -900 kHz < Sample Rate < 3.2 MHz -``` - -The symbol length along with the message type determines the size of sample blocks read and processed on each pass. - -PreambleSymbols = 21 (for SCM) and 32 (for IDM) - -```go -BlockSize = NextPowerOf2(d.Cfg.PreambleLength) - -func NextPowerOf2(v int) int { - return 1 << uint(math.Ceil(math.Log2(float64(v)))) -} -``` - -Valid symbol lengths are given below, with a block size calculated for SCM: - -| Symbol Length | Sample Rate | Block Size | -| ------------- | ----------- | ---------- | -| 7 | 229.376 kHz | 512 | -| 8 | 262.144 kHz | 512 | -| 9 | 294.912 kHz | 512 | - -| Symbol Length | Sample Rate | Block Size | Symbol Length | Sample Rate | Block Size | -| ------------- | ------------ | --------- | ------------- | ----------- | ---------- | -| 28 | 917.504 kHz | 2048 | 39 | 1.277952 MHz | 2048 | -| 29 | 950.272 kHz | 2048 | 40 | 1.310720 MHz | 2048 | -| 30 | 983.040 kHz | 2048 | 41 | 1.343488 MHz | 2048 | -| 31 | 1.015808 MHz | 2048 | 42 | 1.376256 MHz | 2048 | -| 32 | 1.048576 MHz | 2048 | 43 | 1.409024 MHz | 2048 | -| 33 | 1.081344 MHz | 2048 | 44 | 1.441792 MHz | 2048 | -| 34 | 1.114112 MHz | 2048 | 45 | 1.474560 MHz | 2048 | -| 35 | 1.146880 MHz | 2048 | 46 | 1.507328 MHz | 2048 | -| 36 | 1.179648 MHz | 2048 | 47 | 1.540096 MHz | 2048 | -| 37 | 1.212416 MHz | 2048 | 48 | 1.572864 MHz | 2048 | -| 38 | 1.245184 MHz | 2048 | - -| Symbol Length | Sample Rate | Block Size | Symbol Length | Sample Rate | Block Size | -| ------------- | ----------- | ---------- | ------------- | ----------- | ---------- | -| 49 | 1.605632 MHz | 4096 | 74 | 2.424832 MHz | 4096 | -| 50 | 1.638400 MHz | 4096 | 75 | 2.457600 MHz | 4096 | -| 51 | 1.671168 MHz | 4096 | 76 | 2.490368 MHz | 4096 | -| 52 | 1.703936 MHz | 4096 | 77 | 2.523136 MHz | 4096 | -| 53 | 1.736704 MHz | 4096 | 78 | 2.555904 MHz | 4096 | -| 54 | 1.769472 MHz | 4096 | 79 | 2.588672 MHz | 4096 | -| 55 | 1.802240 MHz | 4096 | 80 | 2.621440 MHz | 4096 | -| 56 | 1.835008 MHz | 4096 | 81 | 2.654208 MHz | 4096 | -| 57 | 1.867776 MHz | 4096 | 82 | 2.686976 MHz | 4096 | -| 58 | 1.900544 MHz | 4096 | 83 | 2.719744 MHz | 4096 | -| 59 | 1.933312 MHz | 4096 | 84 | 2.752512 MHz | 4096 | -| 60 | 1.966080 MHz | 4096 | 85 | 2.785280 MHz | 4096 | -| 61 | 1.998848 MHz | 4096 | 86 | 2.818048 MHz | 4096 | -| 62 | 2.031616 MHz | 4096 | 87 | 2.850816 MHz | 4096 | -| 63 | 2.064384 MHz | 4096 | 88 | 2.883584 MHz | 4096 | -| 64 | 2.097152 MHz | 4096 | 89 | 2.916352 MHz | 4096 | -| 65 | 2.129920 MHz | 4096 | 90 | 2.949120 MHz | 4096 | -| 66 | 2.162688 MHz | 4096 | 91 | 2.981888 MHz | 4096 | -| 67 | 2.195456 MHz | 4096 | 92 | 3.014656 MHz | 4096 | -| 68 | 2.228224 MHz | 4096 | 93 | 3.047424 MHz | 4096 | -| 69 | 2.260992 MHz | 4096 | 94 | 3.080192 MHz | 4096 | -| 70 | 2.293760 MHz | 4096 | 95 | 3.112960 MHz | 4096 | -| 71 | 2.326528 MHz | 4096 | 96 | 3.145728 MHz | 4096 | -| 72 | 2.359296 MHz | 4096 | 97 | 3.178496 MHz | 4096 | -| 73 | 2.392064 MHz | 4096 |