frc971/imu_reader/imu.h

#ifndef FRC971_IMU_READER_IMU_H_
#define FRC971_IMU_READER_IMU_H_

#include "aos/events/shm_event_loop.h"
#include "frc971/wpilib/imu_batch_generated.h"

namespace frc971::imu {

// Reads IMU packets from the kernel driver which reads them over spi
// from the Raspberry Pi Pico on the IMU board.
class Imu {
 public:
  // Constructs an IMU reader object.  encoder_scalar is in meters/count.
  Imu(aos::ShmEventLoop *event_loop, double encoder_scalar);
  ~Imu();

 private:
  flatbuffers::Offset<frc971::ADIS16470DiagStat> PackDiagStat(
      flatbuffers::FlatBufferBuilder *fbb, uint16_t value);
  flatbuffers::Offset<frc971::IMUValues> ProcessReading(
      flatbuffers::FlatBufferBuilder *fbb, absl::Span<uint8_t> buf);
  double ConvertValue32(absl::Span<const uint8_t> data, double lsb_per_output);
  double ConvertValue16(absl::Span<const uint8_t> data, double lsb_per_output);

  aos::ShmEventLoop *event_loop_;
  aos::Sender<frc971::IMUValuesBatch> imu_sender_;
  int imu_fd_;

  uint failed_checksums_ = 0;

  double encoder_scalar_;
};

}  // namespace frc971::imu

#endif  // FRC971_IMU_READER_IMU_H_