Module: PWN::SDR::Decoder::LoRa

Defined in:
lib/pwn/sdr/decoder/lora.rb

Overview

Pure-Ruby LoRa / LoRaWAN CSS activity detector.

LoRa is chirp-spread-spectrum over 125/250/500 kHz — recoverable only from raw I/Q at ≥250 ksps, not from a 48 kHz audio tap. Native mode reports chirp-burst duration/energy (from which SF can be estimated). parse_line retained for offline JSON analysis.

Class Method Summary collapse

Class Method Details

.authors ⇒ Object

Author(s)

0day Inc. support@0dayinc.com



60
61
62
 
# File 'lib/pwn/sdr/decoder/lora.rb', line 60

public_class_method def self.authors
  "AUTHOR(S):\n  0day Inc. <support@0dayinc.com>\n"
end

.decode(opts = {}) ⇒ Object

Supported Method Parameters

PWN::SDR::Decoder::LoRa.decode( freq_obj: 'required - freq_obj returned from PWN::SDR::GQRX.init_freq' )



20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
 
# File 'lib/pwn/sdr/decoder/lora.rb', line 20

public_class_method def self.decode(opts = {})
  freq_obj = opts[:freq_obj]
  PWN::SDR::Decoder::Base.run_detector(
    freq_obj: freq_obj,
    protocol: 'LoRa',
    note: 'CSS over 125–500 kHz — native mode reports chirp bursts and estimates SF from duration.',
    threshold: 8.0,
    describe: proc { |b|
      # Preamble ≈ 8 symbols; T_sym = 2^SF / BW. Assume BW=125k.
      t_sym_ms = b[:duration_ms] / 20.0
      sf_est = t_sym_ms.positive? ? Math.log2(t_sym_ms * 125).round.clamp(6, 12) : nil
      { modulation: 'CSS', bw_khz_assumed: 125, sf_estimate: sf_est }.compact
    }
  )
end

.help ⇒ Object

Display Usage for this Module



66
67
68
69
70
71
72
73
74
75
76
 
# File 'lib/pwn/sdr/decoder/lora.rb', line 66

public_class_method def self.help
  puts "USAGE (ruby-native detector, no external binaries):
    #{self}.decode(
      freq_obj: 'required - freq_obj returned from PWN::SDR::GQRX.init_freq'
    )

    #{self}.parse_line(line: '{\"model\":\"LoRa\",\"sf\":7,\"bw\":125,...}')

    #{self}.authors
  "
end

.parse_line(opts = {}) ⇒ Object

Supported Method Parameters

PWN::SDR::Decoder::LoRa.parse_line(line: '"model":"LoRa",...')



39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
 
# File 'lib/pwn/sdr/decoder/lora.rb', line 39

public_class_method def self.parse_line(opts = {})
  line = opts[:line].to_s
  h = begin
    JSON.parse(line, symbolize_names: true)
  rescue StandardError
    { unparsed: line }
  end
  out = { protocol: 'LoRa' }.merge(h)
  bits = []
  bits << "SF#{out[:sf]}" if out[:sf]
  bits << "BW#{out[:bw]}" if out[:bw]
  bits << "CR#{out[:cr]}" if out[:cr]
  bits << "DevAddr=#{out[:devaddr] || out[:id]}" if out[:devaddr] || out[:id]
  bits << "FCnt=#{out[:fcnt]}" if out[:fcnt]
  bits << "len=#{out[:len] || (out[:data].to_s.length / 2)}" if out[:len] || out[:data]
  out[:summary] = "LoRa #{bits.join(' ')}".strip
  out
end