Arduino myFile.write(buff, len) 不工作

Question

我最近在写一些关于获取 IMU 数据并将其保存到 SD 卡的代码。为了提高写入数据的速度，我需要使用二进制格式来保存它，这是我的代码：

byte myData[20];

((long int*)myData)[0] = count;
((long int*)myData)[4] = microSec;
((short int*)myData)[8] = ax;
((short int*)myData)[10] = ay;
((short int*)myData)[12] = az;
((short int*)myData)[14] = gx;
((short int*)myData)[16] = gy;
((short int*)myData)[18] = gz;

myFile3.write(myData, sizeof(myData));

但是完全不行。（但是可以编译，真是迷惑我了。。。）

有人遇到这个问题吗...？

Answer 1

试试这个怎么样：

    byte myData[20];

((long int*)myData)[0] = count;
((long int*)myData)[1] = microSec;
((short int*)myData)[4] = ax;
((short int*)myData)[5] = ay;
((short int*)myData)[6] = az;
((short int*)myData)[7] = gx;
((short int*)myData)[8] = gy;
((short int*)myData)[9] = gz;

myFile3.write(myData, sizeof(myData));

Answer 2

谢谢大家！通过数百次测试解决了这个问题（缺乏 C 编码技能水平真的困扰我 Arduino 编码......）

这是新代码（根据@frarugi87 的建议编辑）

byte myData[20];
  *((long int *)(myData+0)) = count;
  *((long int *)(myData+4)) = microSec;
  *((short int *)(myData+8)) = ax;
  *((short int *)(myData+10)) = ay;
  *((short int *)(myData+12)) = az;
  *((short int *)(myData+14)) = gx;
  *((short int *)(myData+16)) = gy;
  *((short int *)(myData+18)) = gz;

它确实有效并且数据是正确的，例如

数据：0C 6A 30 00

回答：3172876

而且我还找到了另一种方法：

  myFile3.write( (byte*)&count, sizeof(long));
  myFile3.write( (byte*)&microSec, sizeof(long));
  myFile3.write( (byte*)&ax, sizeof(short));
  myFile3.write( (byte*)&ay, sizeof(short));
  myFile3.write( (byte*)&az, sizeof(short));
  myFile3.write( (byte*)&gx, sizeof(short));
  myFile3.write( (byte*)&gy, sizeof(short));
  myFile3.write( (byte*)&gz, sizeof(short));

同样有效，数据格式与第一种编码方式相同

此致！

Arduino myFile.write(buff, len) 不工作

Arduino myFile.write(buff, len) don't work

c

arduino

arduino-uno