Files
intercept/utils/sdr/limesdr.py
Smittix 471cc1ee94 Add bias_t parameter to build_adsb_command()
Completes bias-T support across all SDR command builder methods.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-08 12:17:02 +00:00

145 lines
4.3 KiB
Python

"""
LimeSDR command builder implementation.
Uses SoapySDR-based tools for FM demodulation and signal capture.
LimeSDR supports 100 kHz to 3.8 GHz frequency range.
"""
from __future__ import annotations
from typing import Optional
from .base import CommandBuilder, SDRCapabilities, SDRDevice, SDRType
class LimeSDRCommandBuilder(CommandBuilder):
"""LimeSDR command builder using SoapySDR tools."""
CAPABILITIES = SDRCapabilities(
sdr_type=SDRType.LIME_SDR,
freq_min_mhz=0.1, # 100 kHz
freq_max_mhz=3800.0, # 3.8 GHz
gain_min=0.0,
gain_max=73.0, # Combined LNA + TIA + PGA
sample_rates=[1000000, 2000000, 4000000, 8000000, 10000000, 20000000],
supports_bias_t=False,
supports_ppm=False, # Uses TCXO, no PPM correction needed
tx_capable=True
)
def _build_device_string(self, device: SDRDevice) -> str:
"""Build SoapySDR device string for LimeSDR."""
if device.serial and device.serial != 'N/A':
return f'driver=lime,serial={device.serial}'
return f'driver=lime'
def build_fm_demod_command(
self,
device: SDRDevice,
frequency_mhz: float,
sample_rate: int = 22050,
gain: Optional[float] = None,
ppm: Optional[int] = None,
modulation: str = "fm",
squelch: Optional[int] = None,
bias_t: bool = False
) -> list[str]:
"""
Build SoapySDR rx_fm command for FM demodulation.
For pager decoding with LimeSDR.
Note: LimeSDR does not support bias-T, parameter is ignored.
"""
device_str = self._build_device_string(device)
cmd = [
'rx_fm',
'-d', device_str,
'-f', f'{frequency_mhz}M',
'-M', modulation,
'-s', str(sample_rate),
]
if gain is not None and gain > 0:
# LimeSDR gain is applied to LNAH element
cmd.extend(['-g', f'LNAH={int(gain)}'])
if squelch is not None and squelch > 0:
cmd.extend(['-l', str(squelch)])
# Output to stdout
cmd.append('-')
return cmd
def build_adsb_command(
self,
device: SDRDevice,
gain: Optional[float] = None,
bias_t: bool = False
) -> list[str]:
"""
Build dump1090 command with SoapySDR support for ADS-B decoding.
Uses dump1090 compiled with SoapySDR support, or readsb as alternative.
Note: Requires dump1090 with SoapySDR support or readsb.
Note: LimeSDR does not support bias-T, parameter is ignored.
"""
device_str = self._build_device_string(device)
# Try readsb first (better SoapySDR support), fallback to dump1090
cmd = [
'readsb',
'--net',
'--device-type', 'soapysdr',
'--device', device_str,
'--quiet'
]
if gain is not None:
cmd.extend(['--gain', str(int(gain))])
return cmd
def build_ism_command(
self,
device: SDRDevice,
frequency_mhz: float = 433.92,
gain: Optional[float] = None,
ppm: Optional[int] = None,
bias_t: bool = False
) -> list[str]:
"""
Build rtl_433 command with SoapySDR support for ISM band decoding.
rtl_433 has native SoapySDR support via -d flag.
Note: LimeSDR does not support bias-T, parameter is ignored.
"""
device_str = self._build_device_string(device)
cmd = [
'rtl_433',
'-d', device_str,
'-f', f'{frequency_mhz}M',
'-F', 'json'
]
if gain is not None and gain > 0:
cmd.extend(['-g', str(int(gain))])
# PPM not typically needed for LimeSDR (TCXO)
# but include if specified
if ppm is not None and ppm != 0:
cmd.extend(['-p', str(ppm)])
return cmd
def get_capabilities(self) -> SDRCapabilities:
"""Return LimeSDR capabilities."""
return self.CAPABILITIES
@classmethod
def get_sdr_type(cls) -> SDRType:
"""Return SDR type."""
return SDRType.LIME_SDR