gr-rylr998/grc/rylr998_css_demod.block.yml
Ryan Malloy c839d225a8 Initial release: complete LoRa TX/RX for RYLR998 modems
GNU Radio Out-of-Tree module providing:
- Complete TX chain: PHYEncode → FrameGen → CSSMod
- Complete RX chain: CSSDemod → FrameSync → PHYDecode
- NETWORKID extraction/encoding (0-255 range)
- All SF (7-12) and CR (4/5-4/8) combinations
- Loopback tested with 24/24 configurations passing

Key features:
- Fractional SFD (2.25 downchirp) handling
- Gray encode/decode with proper inverse operations
- gr-lora_sdr compatible decode modes
- GRC block definitions and example flowgraphs
- Comprehensive documentation

Discovered RYLR998 sync word mapping:
  sync_bin_1 = (NETWORKID >> 4) * 8
  sync_bin_2 = (NETWORKID & 0x0F) * 8
2026-02-05 13:38:07 -07:00

54 lines
1.2 KiB
YAML

id: rylr998_css_demod
label: RYLR998 CSS Demodulator
category: '[RYLR998]/Demodulation'
flags: [python, cpp]
documentation: |-
CSS (Chirp Spread Spectrum) demodulator for LoRa signals.
Performs FFT-based peak detection on dechirped LoRa symbols to extract
encoded bin values. Each symbol's bin encodes SF bits of information.
Input: Complex IQ samples at the specified sample rate
Output: Integer bin values (0 to 2^SF - 1)
The demodulation process:
1. Multiply received signal by reference downchirp (dechirp)
2. FFT to convert frequency ramp to single tone
3. Find peak bin location
templates:
imports: from rylr998 import css_demod
make: rylr998.css_demod(sf=${sf}, sample_rate=${sample_rate})
parameters:
- id: sf
label: Spreading Factor
dtype: int
default: 9
options: [7, 8, 9, 10, 11, 12]
option_labels: ['SF7', 'SF8', 'SF9', 'SF10', 'SF11', 'SF12']
- id: sample_rate
label: Sample Rate (Hz)
dtype: real
default: 250e3
- id: bw
label: Bandwidth (Hz)
dtype: real
default: 125e3
inputs:
- label: in
domain: stream
dtype: complex
outputs:
- label: out
domain: message
dtype: int
optional: false
file_format: 1