id: apollo_nrz_encoder
label: Apollo NRZ Encoder
category: '[Apollo USB]'
flags: [python]

parameters:
- id: bit_rate
  label: Bit Rate (bps)
  dtype: int
  default: '51200'
  options: ['51200', '1600']
  option_labels: ['High (51.2 kbps)', 'Low (1.6 kbps)']
- id: sample_rate
  label: Sample Rate
  dtype: real
  default: '5120000'

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

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

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

documentation: |-
  Apollo NRZ Encoder

  Converts a stream of byte values (0 or 1) to a Non-Return-to-Zero
  baseband waveform at the specified sample rate.

  Mapping:
    bit 1 -> +1.0 (held for bit period)
    bit 0 -> -1.0 (held for bit period)

  Each bit value is upsampled by samples_per_bit = sample_rate / bit_rate.
  At the default high rate (51.2 kbps, 5.12 MHz), this is 100 samples
  per bit. At low rate (1.6 kbps), it is 3200 samples per bit.

  This is the transmit-side counterpart to the slicer in bpsk_demod.

  Parameters:
    bit_rate: PCM bit rate in bps (51200 high, 1600 low)
    sample_rate: Output sample rate in Hz (default 5.12 MHz)

file_format: 1