daq.cpp

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// Copyright (c) 2024 anabrid GmbH
// Contact: https://www.anabrid.com/licensing/
// SPDX-License-Identifier: MIT OR GPL-2.0-or-later
 
#include <proto/main.pb.h>
#include <Arduino.h>
#include <algorithm>
#include <bitset>
 
#include <carrier/carrier.h>
#include <daq/daq.h>
 
std::array<int16_t, daq::NUM_CHANNELS> daq::details::raw_zero_offsets = {0};
 
size_t daq::raw_to_normalized(uint16_t raw) {
  // exact conversion is 0.152658243301, but we only care about so much precision
  return std::max(std::min((static_cast<unsigned int>(raw) * 1527u) / 10000u, 2500u), 0u);
}
 
float daq::raw_to_float(const uint16_t raw, const int16_t raw_zero_offset) {
  return map(static_cast<float>(raw + raw_zero_offset), details::RAW_MINUS_ONE_POINT_TWO_FIVE,
             details::RAW_PLUS_ONE_POINT_TWO_FIVE, -1.25f, 1.25f);
}
 
std::array<float, daq::NUM_CHANNELS> daq::raw_to_float(std::array<uint16_t, NUM_CHANNELS> raw) {
  static_assert(NUM_CHANNELS == 8, "Adapt raw_to_float when changing NUM_CHANNELS.");
  // Maybe easier to optimize for the compiler than std::transform
  return {
      raw_to_float(raw[0], details::raw_zero_offsets[0]), raw_to_float(raw[1], details::raw_zero_offsets[1]),
      raw_to_float(raw[2], details::raw_zero_offsets[2]), raw_to_float(raw[3], details::raw_zero_offsets[3]),
      raw_to_float(raw[4], details::raw_zero_offsets[4]), raw_to_float(raw[5], details::raw_zero_offsets[5]),
      raw_to_float(raw[6], details::raw_zero_offsets[6]), raw_to_float(raw[7], details::raw_zero_offsets[7])};
}
 
std::array<uint16_t, daq::NUM_CHANNELS> daq::raw_to_offset_corrected(std::array<uint16_t, NUM_CHANNELS> raw) {
  static_assert(NUM_CHANNELS == 8, "Adapt raw_to_corrected when changing NUM_CHANNELS.");
  // Maybe easier to optimize for the compiler than std::transform
  return {static_cast<uint16_t>(raw[0] + details::raw_zero_offsets[0]),
          static_cast<uint16_t>(raw[1] + details::raw_zero_offsets[1]),
          static_cast<uint16_t>(raw[2] + details::raw_zero_offsets[2]),
          static_cast<uint16_t>(raw[3] + details::raw_zero_offsets[3]),
          static_cast<uint16_t>(raw[4] + details::raw_zero_offsets[4]),
          static_cast<uint16_t>(raw[5] + details::raw_zero_offsets[5]),
          static_cast<uint16_t>(raw[6] + details::raw_zero_offsets[6]),
          static_cast<uint16_t>(raw[7] + details::raw_zero_offsets[7])};
}