id: apollo_ranging_mod
label: Apollo Ranging Modulator
category: '[Apollo USB]'
flags: [python]

parameters:
- id: chip_rate
  label: Chip Rate (Hz)
  dtype: int
  default: '993963'
- id: sample_rate
  label: Sample Rate (Hz)
  dtype: real
  default: '5120000'

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

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

templates:
  imports: from apollo.ranging_mod import ranging_mod
  make: apollo.ranging_mod.ranging_mod(chip_rate=${chip_rate}, sample_rate=${sample_rate})

documentation: |-
  Apollo Ranging Modulator

  NRZ-encodes PRN ranging chips (byte 0/1) to float (+1/-1) at the
  specified sample rate. Output is suitable for summing with other
  subcarriers before PM carrier modulation.

  At the default 5.12 MHz sample rate, each chip occupies ~5 samples.

  This is the same NRZ transform as the PCM NRZ Encoder but configured
  for the ranging chip rate (~994 kchip/s) instead of the PCM bit rate.

  Parameters:
    chip_rate: PRN chip rate (default 993,963 Hz)
    sample_rate: Output sample rate (default 5.12 MHz)

file_format: 1