mpu9250和mpu6050的区别

MPU9250和MPU6050都是由InvenSense公司生产的MEMS运动传感器，二者的主要区别在于以下几个方面：
1. MPU9250比MPU6050多了一个地磁传感器，可以提供更加准确的方向信息。
2. MPU9250的DMP（Digital Motion Processor）算法单元比MPU6050更加先进，可以提供更加精确的姿态解算和运动跟踪。
3. MPU9250的通信接口支持SPI和I2C两种协议，而MPU6050只支持I2C协议。
4. MPU9250的功耗比MPU6050更低，性能更加稳定。

下面是一个演示如何使用MPU9250获取姿态信息的例子：

import smbus
import math
 
# MPU9250的I2C地址
MPU9250_ADDRESS = 0x68
 
# 加速度计和陀螺仪的校准参数
accel_bias = [0.0, 0.0, 0.0]
gyro_bias = [0.0, 0.0, 0.0]
 
# 初始化I2C总线
bus = smbus.SMBus(1)
 
# 初始化MPU9250
bus.write_byte_data(MPU9250_ADDRESS, 0x6B, 0x00) # 解除休眠状态
bus.write_byte_data(MPU9250_ADDRESS, 0x1A, 0x06) # 配置陀螺仪量程为+-500dps
bus.write_byte_data(MPU9250_ADDRESS, 0x1B, 0x08) # 配置加速度计量程为+-4g
bus.write_byte_data(MPU9250_ADDRESS, 0x1C, 0x08) # 配置磁力计量程为16bit
bus.write_byte_data(MPU9250_ADDRESS, 0x37, 0x02) # 配置磁力计连续测量模式
 
# 获取加速度计和陀螺仪的校准参数
for i in range(1000):
    accel_raw = bus.read_i2c_block_data(MPU9250_ADDRESS, 0x3B, 6)
    gyro_raw = bus.read_i2c_block_data(MPU9250_ADDRESS, 0x43, 6)
    accel_bias[0] += (accel_raw[0] << 8 | accel_raw[1])
    accel_bias[1] += (accel_raw[2] << 8 | accel_raw[3])
    accel_bias[2] += (accel_raw[4] << 8 | accel_raw[5])
    gyro_bias[0] += (gyro_raw[0] << 8 | gyro_raw[1])
    gyro_bias[1] += (gyro_raw[2] << 8 | gyro_raw[3])
    gyro_bias[2] += (gyro_raw[4] << 8 | gyro_raw[5])
accel_bias[0] /= 1000
accel_bias[1] /= 1000
accel_bias[2] /= 1000
gyro_bias[0] /= 1000
gyro_bias[1] /= 1000
gyro_bias[2] /= 1000
 
# 循环读取姿态信息
while True:
    # 读取加速度计、陀螺仪和磁力计数据
    accel_raw = bus.read_i2c_block_data(MPU9250_ADDRESS, 0x3B, 6)
    gyro_raw = bus.read_i2c_block_data(MPU9250_ADDRESS, 0x43, 6)
    mag_raw = bus.read_i2c_block_data(MPU9250_ADDRESS, 0x03, 7)
 
    # 将原始数据转换为物理量
    accel_x = (accel_raw[0] << 8 | accel_raw[1]) / 16384.0 - accel_bias[0]
    accel_y = (accel_raw[2] << 8 | accel_raw[3]) / 16384.0 - accel_bias[1]
    accel_z = (accel_raw[4] << 8 | accel_raw[5]) / 16384.0 - accel_bias[2]
    gyro_x = (gyro_raw[0] << 8 | gyro_raw[1]) / 131.0 - gyro_bias[0]
    gyro_y = (gyro_raw[2] << 8 | gyro_raw[3]) / 131.0 - gyro_bias[1]
    gyro_z = (gyro_raw[4] << 8 | gyro_raw[5]) / 131.0 - gyro_bias[2]
    mag_x = (mag_raw[1] << 8 | mag_raw[0]) * 10.0 / 32768.0
    mag_y = (mag_raw[3] << 8 | mag_raw[2]) * 10.0 / 32768.0
    mag_z = (mag_raw[5] << 8 | mag_raw[4]) * 10.0 / 32768.0
 
    # 计算欧拉角
    roll = math.atan2(accel_y, math.sqrt(accel_x * accel_x + accel_z * accel_z))
    pitch = math.atan2(-accel_x, math.sqrt(accel_y * accel_y + accel_z * accel_z))
    yaw = math.atan2(mag_y * math.cos(roll) - mag_z * math.sin(roll), mag_x * math.cos(pitch) + mag_y * math.sin(pitch) * math.sin(roll) + mag_z * math.sin(pitch) * math.cos(roll))
 
    # 输出欧拉角
    print("Roll: %.2f, Pitch: %.2f, Yaw: %.2f" % (roll * 180 / math.pi, pitch * 180 / math.pi, yaw * 180 / math.pi))