id: apollo_fm_demod
label: Apollo FM Demod
category: '[Apollo USB]'
flags: [python]

parameters:
- id: carrier_pll_bw
  label: Carrier PLL Bandwidth
  dtype: real
  default: '0.02'
- id: fm_deviation_hz
  label: FM Deviation (Hz)
  dtype: real
  default: '500000'
- id: sample_rate
  label: Sample Rate
  dtype: real
  default: '5120000'

inputs:
- label: in
  domain: stream
  dtype: complex

outputs:
- label: out
  domain: stream
  dtype: float

templates:
  imports: from apollo.fm_demod import fm_demod
  make: apollo.fm_demod.fm_demod(carrier_pll_bw=${carrier_pll_bw}, fm_deviation_hz=${fm_deviation_hz}, sample_rate=${sample_rate})

documentation: |-
  Apollo FM Demodulator

  Extracts frequency modulation from complex baseband signal.
  Uses a carrier tracking PLL followed by quadrature demodulation
  to recover the instantaneous frequency (composite SCO signal).

  Output is normalized so +/- full FM deviation maps to +/- 1.0.

  Parameters:
    carrier_pll_bw: PLL loop bandwidth in rad/sample (default 0.02)
    fm_deviation_hz: Expected max FM deviation in Hz (default 500 kHz)
    sample_rate: Input sample rate in Hz (default 5.12 MHz)

file_format: 1