bno055 IMU校准

Question

我正试着从IMU BNO055中获得一些阅读，下面是ADA结果的实现。

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

似乎我无法通过校准步骤。

BNO055手册可以在下面找到：https://cdn-shop.adafruit.com/datasheets/BST_BNO055_DS000_12.pdf

我不是使用库，而是直接使用I2C进行通信，并从设备寄存器中读取和写入。

我正在做的配置如下：

    // 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，我应该等待芯片的内部校准。但它似乎并没有完成这个任务。

我正在检查它通过检查寄存器0x35，这应该是>0，如果校准完成。

         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，我发现了一些建议(也是根据IMU手册)，用这个设备在空气中制造一个8符号，我做到了，但是校准工作还是没有完成。

我不认为这是一个电源问题(我在Bosh论坛上找到了一些关于这个问题的参考资料)，因为我将VIN连接到5.0V，3VO到3.3V，GND连接到GND。

对此的任何评论都会有很大帮助。我的设备配置错了吗？我遗漏了什么登记簿吗？

谢谢!

Answer 1

我在ADAFruit网页上跟进了讨论。

请参见：

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

总之，采取的办法是：

1. 进入配置模式(OP_MODE (0x3D)设置为0x00 )
2. ，我们选择注册映射0。( 0x00)
3. Internal (0x37)被设置为0x00 )PAGE_ID (0x3F)将设备(SYS_TRIGGER (0x3F)设置为0x20)
4. 电源模式设置为正常模式(POWER_MODE (0x3E)被设置为在SYS_TRIGGER中选择的POWER_MODE时钟(SYS_TRIGGER (0x3F)被设置为0x00)
5. OP_MODE，因为我想要) (OP_MODE (0x3D)设置为0x0B)

可选，根据Gammaburst ADA水果论坛的建议：

1. //AXIS_MAP_CONFIG 0x41寄存器到0x21.
2. //AXIS_MAP_SIGN 0x42寄存器到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);