bno055 IMU 校准

Question

我正在尝试从 IMU BNO055 中获取一些读数，下面是 ADA Fruit 的实现。

https://cdn-learn.adafruit.com/downloads/pdf/adafruit-bno055-absolute-orientation-sensor.pdf

我好像无法通过校准步骤。

BNO055 手册如下： https://cdn-shop.adafruit.com/datasheets/BST_BNO055_DS000_12.pdf

我没有使用库，而是直接使用 I2C 进行通信并从设备寄存器读取和写入。

我做的配置如下：

    // The opening of the device and so on, works, so the line below is not a problem.
    if (ioctl(data_exchange->file_imu_sensor, I2C_SLAVE, data_exchange->imu_addr) < 0) {
                 printf("Impossible to communicate with the IMU in the i2c. Make sure that the address you have is correct!\n");
                 exit(1);
             }
    // Here is where I start with the configuration. First I reset the device.
    //SYS_TRIGGER Register. ADD 3F
    //CLK_SEL (0 internal oscillator) REST_INT(reset interrumptions)RST_SYS(1 to reset) x x x x Self_TEST(1 to make a self test.)
    // 00xxxx0
    buf[0] = 0x3F;
    buf[1] = 0x20; //00100000
    write_buf(data_exchange,buf,3);
    printf("IMU WAS COMMANDED TO RESET");
    sleep(1); //It needs some time to reset. With one sec should be sufficient.
    // Here I start with the real configuration.

    // G range 2G xxxxxx00
    // BW 7.81Hz  xxx000xx
    // Op mod normal 000xxxxx
    //So I will write a 0 to the register ACC_condfi
    buf[0] = 0x0D;
    buf[1] = 0x00;
    write_buf(data_exchange,buf,3);
    // Now unit selection.UNIT_SEL Page 30.
    //Accelaration m/s2 xxxxxxx0b
    // Magnetic field in micro Teslas (always)
    // Angular rate defrees ps xxxxxx0xb
    // Euler angles Degress> xxxxxxxb
    // Quaternion in Quaernion units always.
    //Temperatyre deg xxx0xxxxb
    // NPI The data output format can be selected by writing to the UNIT_SEL register, this allows user to switch between the orientation definition described by Windows and Android operating systems
    // Windows> 0xxxxxxxb
    // Android> 1xxxxxxxb. Page 30.
    // Bits 5 and 6 are reserved. So it does not matter. So we write a 0.
    buf[0] = 0x03;
    buf[1] = 0x00;
    write_buf(data_exchange,buf,3);

    //We now need to set the operation mode:
    //Register OPR_MODE Page 21.
    //Fusion mode NDOF. xxxx1100b
    buf[0] = 0x1C;
    buf[1] = 0x0C; //00001100
    write_buf(data_exchange,buf,3);

    // GYR_Config_0
    buf[0] = 0x0B;
    buf[1] = 0x00; //00001100
    write_buf(data_exchange,buf,3);


    // PWR_MODE. Normal mode is xxxxxx00b
    buf[0] = 0x3E;
    buf[1] = 0x00; //00000000
    write_buf(data_exchange,buf,3);

现在，我应该等待对芯片进行内部校准。但它似乎并没有完成它。

我正在通过检查寄存器 0x35 来检查它，如果校准完成，它应该 >0。

         char buf[10];
         int status=0;
         read_buf(dataset_pointer,0x35,3,buf);
         status=buf[0];
         if(status>0){
//Here is where I perform all the reading and so on.
}

我是不是在配置中遗漏了什么？我在互联网上查了一下，发现了一些关于用设备在空中制作一个 8 符号的建议（也根据 IMU 手册），我照做了，但是校准还没有完成。

我认为这不是电源问题（我在 Bosh 论坛上找到了一些相关参考资料），因为我将 VIN 连接到 5.0V，3VO 连接到 3.3V，GND 连接到 GND。

对此的任何评论都会有很大帮助。我配置设备错误吗？我缺少任何寄存器吗？

谢谢！

Answer 1

我跟进了 ADAFruit 网页中的讨论。

参见：

https://forums.adafruit.com/viewtopic.php?f=19&t=164389&p=808106#p808106

总而言之，方法是：

进入配置模式（OP_MODE（0x3D）设置为0x00）
我们选择 Register 映射 0。（PAGE_ID (0x37) 设置为 0x00 ）
我们重置设备（SYS_TRIGGER (0x3F) 设置为 0x20）
电源模式到正常模式（POWER_MODE（0x3E）设置为0x00）
在 SYS_TRIGGER 中选取的内部时钟（SYS_TRIGGER (0x3F) 设置为 0x00）
OP_MODE设置为NDOF（因为我想）（OP_MODE（0x3D）设置为0x0B）

可选，根据 Gammaburst ADA Fruit 论坛的建议：

//AXIS_MAP_CONFIG 0x41 注册到 0x21.
//AXIS_MAP_SIGN 0x42 注册到 0x02;

.

buf[0] = 0X3D; //OP_MODE;
buf[1] = 0x00; // Config mode
write_buf(data_exchange,buf,3);


buf[0] = 0x07; // BNO055_PAGE_ID_ADDR
buf[1] = 0x00; // We want to access the Register Map 0. See page 51 of the Manual https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bno055-ds000.pdf
write_buf(data_exchange,buf,3);

buf[0] = 0x3F; //(SYS_TRIGGER)
buf[1] = 0x20; //00100000 Reset!
write_buf(data_exchange,buf,3);
printf("IMU WAS COMMANDED TO RESET");
sleep(0.65); //It needs some time to reset. With one sec should be sufficient.


buf[0] = 0x3E; //(POWER_MODE)
buf[1] = 0x00; //00000000 Normal mode
write_buf(data_exchange,buf,3);


buf[0] = 0x3F; // SYS_TRIGGER
buf[1] = 0x00; //00000000 Iternal clock
write_buf(data_exchange,buf,3);

buf[0] = 0X3D; //OP_MODE;
buf[1] = 0x0B; //NDOF
write_buf(data_exchange,buf,3);

//These two are optional as per suggestion from gammaburst user in ADAFruit forums
//AXIS_MAP_CONFIG
buf[0] = 0x41;
buf[1] = 0x21;
write_buf(data_exchange,buf,3);


// AXIS_MAP_SIGN
 buf[0] = 0x42;
 buf[1] = 0x02;
 write_buf(data_exchange,buf,3);

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