I am trying to get some reading from the IMU BNO055, the implementation from ADA Fruit below.
https://cdn-learn.adafruit.com/downloads/pdf/adafruit-bno055-absolute-orientation-sensor.pdf
It seems like I am not able to pass the calibration step.
The BNO055 manual can be found below: https://cdn-shop.adafruit.com/datasheets/BST_BNO055_DS000_12.pdf
I am not using libraries but communicating using I2C directly and reading and writing from the device registers.
The configuration I am doing is as follows:
// 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);
Now, I am supposed to wait for the internal calibration of the chip to be performed. But it seems like it does not finish doing that.
I am checking it by means of checking the register 0x35, which should be >0 if the calibration was finished.
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.
}
Am I missing something in the configuration? I checked on the Internet and I found some suggestions (as per the IMU manual, too) about making an 8 symbol in the air with the device, which I did, but the calibration is not finished anyway.
I don't think it is a power issue (I found some references about that in the Bosh forums) because I connected VIN to 5.0V, 3VO to 3.3V and GND to GND.
Any comment on this would be of great help. Am I configuring the device wrong? Am I missing any register?
Thanks!
I followed up the discussion in the ADAFruit webpage.
See:
https://forums.adafruit.com/viewtopic.php?f=19&t=164389&p=808106#p808106
In summary the approach would be:
Optional, as per Gammaburst ADA Fruit forum suggestion:
.
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);