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#include "imu.hpp"
imu::imu(i2c_inst_t* inst, uint8_t addr, uint8_t id, imu_opmode_t mode) {
this->inst = inst;
this->addr = addr;
this->id = id;
this->mode = mode;
}
void imu::reset() {
this->buffer[0] = SYS_TRIGGER;
this->buffer[1] = 0x20; // Reset system
i2c_write_blocking(this->inst, this->addr, buffer, 2, true);
sleep_ms(1000); // Wait 650ms for the sensor to reset
}
void imu::initialize() {
sleep_ms(1000); // Wait 650ms for the sensor to reset
uint8_t chip_id_addr = CHIP_ID;
uint8_t read_id = 0x00;
while (read_id != this->id) {
i2c_write_blocking(this->inst, this->addr, &chip_id_addr, 1, false);
i2c_read_blocking(this->inst, this->addr, &read_id, 1, false);
sleep_ms(100);
}
// Use internal oscillator
this->buffer[0] = SYS_TRIGGER;
this->buffer[1] = 0x40; // Set to use internal oscillator
i2c_write_blocking(this->inst, this->addr, this->buffer, 2, true);
sleep_ms(50);
// Reset all interrupt status bits
this->buffer[0] = SYS_TRIGGER;
this->buffer[1] = 0x01; // Reset interrupt status
i2c_write_blocking(this->inst, this->addr, this->buffer, 2, true);
sleep_ms(50);
// Set to normal power mode
this->buffer[0] = POWER_MODE;
this->buffer[1] = 0x00; // Normal power mode
i2c_write_blocking(this->inst, this->addr, this->buffer, 2, true);
sleep_ms(50);
// Default Axis Config
this->buffer[0] = AXIS_MAP_CONFIG;
this->buffer[1] = 0x24; // P1=Z, P2=Y, P3=X
i2c_write_blocking(this->inst, this->addr, this->buffer, 2, true);
sleep_ms(50);
// Default Axis Sign
this->buffer[0] = AXIS_MAP_SIGN;
this->buffer[1] = 0x00; // P1=Positive, P2=Positive, P3=Positive
i2c_write_blocking(this->inst, this->addr, this->buffer, 2, true);
sleep_ms(50);
// Set units to m/s^2
this->buffer[0] = UNIT_SELECTION;
this->buffer[1] = 0x00; // Windows, Celsius, Degrees, DPS, m/s^2
i2c_write_blocking(this->inst, this->addr, this->buffer, 2, true);
sleep_ms(200);
uint8_t sensor_offsets[19];
sensor_offsets[0] = ACCELERATION_OFFSET_X_LSB;
sensor_offsets[1] = 0x00;
sensor_offsets[2] = 0x00;
sensor_offsets[3] = 0x00;
sensor_offsets[4] = 0x00;
sensor_offsets[5] = 0x00;
sensor_offsets[6] = 0x00;
sensor_offsets[7] = 0x00;
sensor_offsets[8] = 0x00;
sensor_offsets[9] = 0x00;
sensor_offsets[10] = 0x00;
sensor_offsets[11] = 0x00;
sensor_offsets[12] = 0x00;
sensor_offsets[13] = 0x00;
sensor_offsets[14] = 0x00;
sensor_offsets[15] = 0x00;
sensor_offsets[16] = 0x00;
sensor_offsets[17] = 0x00;
sensor_offsets[18] = 0x00;
i2c_write_blocking(this->inst, this->addr, sensor_offsets, 19, true);
sleep_ms(200);
// The default operation mode after power-on is CONFIG
// Set to desired mode
this->buffer[0] = OPERATION_MODE;
this->buffer[1] = this->mode; // NDOF
i2c_write_blocking(this->inst, this->addr, this->buffer, 2, false);
sleep_ms(100);
}
void imu::calibration_status(calibration_status_t* status) {
read_register(CALIBRATION_STATUS, 1, this->buffer);
status->mag = ((this->buffer[0] & 0b00000011) >> 0);
status->accel = ((this->buffer[0] & 0b00001100) >> 2);
status->gyro = ((this->buffer[0] & 0b00110000) >> 4);
status->sys = ((this->buffer[0] & 0b11000000) >> 6);
}
void imu::linear_acceleration(Eigen::Vector3f& vec) {
read_register(LINEAR_ACCELERATION_X_LSB, 6, this->accel_buffer);
int16_t x, y, z;
x = y = z = 0;
x = ((int16_t)this->accel_buffer[0]) | (((int16_t)this->accel_buffer[1]) << 8);
y = ((int16_t)this->accel_buffer[2]) | (((int16_t)this->accel_buffer[3]) << 8);
z = ((int16_t)this->accel_buffer[4]) | (((int16_t)this->accel_buffer[5]) << 8);
vec(0) = ((float)x) / 100.0;
vec(1) = ((float)y) / 100.0;
vec(2) = ((float)z) / 100.0;
}
void imu::quaternion(Eigen::Vector4f& vec) {
read_register(QUATERNION_W_LSB, 8, this->quat_buffer);
int16_t w, x, y, z;
w = x = y = z = 0;
w = ((int16_t)this->quat_buffer[0]) | (((int16_t)this->quat_buffer[1]) << 8);
x = ((int16_t)this->quat_buffer[2]) | (((int16_t)this->quat_buffer[3]) << 8);
y = ((int16_t)this->quat_buffer[4]) | (((int16_t)this->quat_buffer[5]) << 8);
z = ((int16_t)this->quat_buffer[6]) | (((int16_t)this->quat_buffer[7]) << 8);
vec(0) = ((float)w) / 16384.0;
vec(1) = ((float)x) / 16384.0;
vec(2) = ((float)y) / 16384.0;
vec(3) = ((float)z) / 16384.0;
}
void imu::quaternion_euler(Eigen::Vector3f& angles, Eigen::Vector4f& quat) {
// roll (x-axis rotation)
float sinr_cosp = 2 * (quat(0) * quat(1) + quat(2) * quat(3));
float cosr_cosp = 1 - 2 * (quat(1) * quat(1) + quat(2) * quat(2));
angles(0) = Eigen::numext::atan2(sinr_cosp, cosr_cosp);
// pitch (y-axis rotation)
float sinp = Eigen::numext::sqrt(1 + 2 * (quat(0) * quat(2) - quat(1) * quat(3)));
float cosp = Eigen::numext::sqrt(1 - 2 * (quat(0) * quat(2) - quat(1) * quat(3)));
angles(1) = 2 * Eigen::numext::atan2(sinp, cosp) - M_PI / 2;
// yaw (z-axis rotation)
float siny_cosp = 2 * (quat(0) * quat(3) + quat(1) * quat(2));
float cosy_cosp = 1 - 2 * (quat(2) * quat(2) + quat(3) * quat(3));
angles(2) = Eigen::numext::atan2(siny_cosp, cosy_cosp);
}
uint32_t imu::expose_acceleration_buffer(uint8_t** buffer) {
*buffer = this->accel_buffer;
return sizeof(this->accel_buffer);
}
uint32_t imu::expose_quaternion_buffer(uint8_t** buffer) {
*buffer = this->quat_buffer;
return sizeof(this->quat_buffer);
}
void imu::read_register(uint8_t reg, size_t len, uint8_t* buffer) {
i2c_write_blocking(this->inst, this->addr, ®, 1, true);
i2c_read_blocking(this->inst, this->addr, buffer, len, false);
}
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