BatteryStatus

数据结构

字节索引	类型	字段含义
0-3	uint32	故障码
4-7	float32	电池总电压 [V]
8-11	float32	回路电流 [A]，充电为正，放电为负
12-15	float32	剩余电量百分比 0-100 [%]
16-17	uint16	温度传感器数量
18-19	uint16	保留字段，必须为 0
20-$(20+4 \times T-1)$	float32[]	温度传感器数组 [℃]，T 为温度数量

固定头部为 20 字节，因此总长度为 $20 + temp\_count \times 4$ 字节

示例

C++ 示例

struct BatteryStatusHeader {
  uint32_t fault_code;
  float voltage;
  float current;
  float soc;
  uint16_t temp_count;
  uint16_t reserved;
};

// payload = BatteryStatusHeader + temp_count * float

Rust 示例

#[repr(C)]
#[derive(Clone, Copy, Debug, Default)]
pub struct BatteryStatusHeader {
    pub fault_code: u32,
    pub voltage: f32,
    pub current: f32,
    pub soc: f32,
    pub temp_count: u16,
    pub reserved: u16,
}

const _: () = {
    assert!(core::mem::size_of::<BatteryStatusHeader>() == 20);
    assert!(core::mem::align_of::<BatteryStatusHeader>() == 4);
};

Dart 示例

import 'dart:typed_data';

final class BatteryStatusView {
  static const int headerLength = 20;
  static const int tempLength = Float32List.bytesPerElement;

  final ByteBuffer buffer;
  final ByteData header;
  final int offsetInBytes;

  BatteryStatusView(this.buffer, [this.offsetInBytes = 0])
      : header = ByteData.view(buffer, offsetInBytes, headerLength);

  int get faultCode => header.getUint32(0, Endian.little);
  double get voltage => header.getFloat32(4, Endian.little);
  double get current => header.getFloat32(8, Endian.little);
  double get soc => header.getFloat32(12, Endian.little);
  int get tempCount => header.getUint16(16, Endian.little);
  int get byteLength => headerLength + tempCount * tempLength;

  Float32List get temps => Float32List.view(
        buffer,
        offsetInBytes + headerLength,
        tempCount,
      );
}

Java 示例

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;

public final class BatteryStatusView {
  public static final int HEADER_LENGTH = 20;
  public static final int TEMP_LENGTH = Float.BYTES;

  private final ByteBuffer buffer;
  private final int offset;

  public BatteryStatusView(ByteBuffer buffer, int offset) {
    this.buffer = buffer.order(ByteOrder.LITTLE_ENDIAN);
    this.offset = offset;
  }

  public int faultCode() { return buffer.getInt(offset); }
  public float voltage() { return buffer.getFloat(offset + 4); }
  public float current() { return buffer.getFloat(offset + 8); }
  public float soc() { return buffer.getFloat(offset + 12); }
  public int tempCount() { return Short.toUnsignedInt(buffer.getShort(offset + 16)); }
  public int byteLength() { return HEADER_LENGTH + tempCount() * TEMP_LENGTH; }

  public FloatBuffer temps() {
    return buffer.slice(offset + HEADER_LENGTH, tempCount() * TEMP_LENGTH)
        .order(ByteOrder.LITTLE_ENDIAN)
        .asFloatBuffer();
  }
}