老师有个项目，让我搞惯导这一块,虽然最后也没有用上廉价的MPU6050，而是用了一两万的Xsens。但是本人还是想写一下MPU6050，虽然技术含量不高，但是写下来，留个纪念吧。
首先是MPU6050，属于MEMS传感器，现在做四轴的用这款芯片的很多，它集成了三轴陀螺仪+三轴加速度计，因为官方提供DMP库，这样就大大方便了开发，使用硬解，解放主控资源。自己买回来MPU6050后，测了其静态漂移。把MPU6050模块插在面包板上，微处理器用的是stm32，通讯方式是IIC，姿态解算用的是硬件解算，用的例程是原子的，然后通过每隔一段时间记录一次,mpu6050自带的DMP进行解算，直接输出四元数，然后通过四元数转化转换为对应的姿态角，但是没有Z轴上的参考量，所以Yaw是不准的。(Time是次数的意思，当时的时间间隔忘记了）
发现半个小时，yaw漂6--7度。对于微型小四轴来说够用了，一般微型小四轴也就飞7、8分钟左右。通过mpu6050，我们可以得到roll，pitch，yaw。至于mpu6050的源码，大家自己看原子的。这里就不放了。
其次是HMC5883，它是磁力计，可以测量x,y,z方向上的磁场。它与微处理器也是通过IIC通讯。至于它的有关介绍可以看DATASHEET。其代码如下：
#include "HMC5883L.h"
#include "sys.h"
#include "delay.h"
#include "usart.h"
#define SlaveAddress 0x3c
void Init_HMC5883(void)
{
MPU_IIC_Init();
Write_HMC5883_Byte(0x02,0x00);
}
u8 Write_HMC5883_Byte(u8 add, u8 da)
{
MPU_IIC_Start();
MPU_IIC_Send_Byte(SlaveAddress);
if(MPU_IIC_Wait_Ack())
{
MPU_IIC_Stop();
return 1;
}
MPU_IIC_Send_Byte(add);
MPU_IIC_Wait_Ack();
MPU_IIC_Send_Byte(da);
if(MPU_IIC_Wait_Ack())
{
MPU_IIC_Stop();
return 1;
}
MPU_IIC_Stop();
return 0;
}
u8 Read_HMC5883_Byte(u8 REG_Address)
{
u8 REG_data;
MPU_IIC_Start();
MPU_IIC_Send_Byte(SlaveAddress);
MPU_IIC_Wait_Ack();
MPU_IIC_Send_Byte(REG_Address);
MPU_IIC_Wait_Ack();
MPU_IIC_Start();
MPU_IIC_Send_Byte(SlaveAddress+1);
MPU_IIC_Wait_Ack();
REG_data=MPU_IIC_Read_Byte(0);
MPU_IIC_Stop();
return REG_data;
}
void Multiple_read_HMC5883(u8*BUF)
{ u8 i;
MPU_IIC_Start();
MPU_IIC_Send_Byte(SlaveAddress);
MPU_IIC_Wait_Ack();
MPU_IIC_Send_Byte(0x03);
MPU_IIC_Wait_Ack();
MPU_IIC_Start();
MPU_IIC_Send_Byte(SlaveAddress+1);
MPU_IIC_Wait_Ack();
for (i=0; i<6; i++)
{
if (i == 5)
{
BUF[i] = MPU_IIC_Read_Byte(0);
}
else
{
BUF[i] = MPU_IIC_Read_Byte(1);
}
}
MPU_IIC_Stop();
}#include "BMP180.h"
#include "delay.h"
#include "mpuiic.h"
#include "sys.h"
long result_UT=0;
long result_UP=0;
short ac1;
short ac2;
short ac3;
unsigned short ac4;
unsigned short ac5;
unsigned short ac6;
short b1;
short b2;
short mb;
short mc;
short md;
u16 Multiple_read(u8 ST_Address)
{
u8 msb, lsb;
u16 _data;
MPU_IIC_Start();
MPU_IIC_Send_Byte(BMP180_SlaveAddress);
MPU_IIC_Wait_Ack();
MPU_IIC_Send_Byte(ST_Address);
MPU_IIC_Wait_Ack();
MPU_IIC_Start();
MPU_IIC_Send_Byte(BMP180_SlaveAddress+1);
MPU_IIC_Wait_Ack();
msb = MPU_IIC_Read_Byte(1);
lsb = MPU_IIC_Read_Byte(0);
MPU_IIC_Stop();
delay_ms(5);
_data = msb << 8;
_data |= lsb;
return _data;
}
//********************************************************************
u16 bmp180ReadTemp(void)
{
MPU_IIC_Start();
MPU_IIC_Send_Byte(BMP180_SlaveAddress);
MPU_IIC_Wait_Ack();
MPU_IIC_Send_Byte(0xF4);
while(MPU_IIC_Wait_Ack());
MPU_IIC_Send_Byte(0x2E);
while(MPU_IIC_Wait_Ack());
MPU_IIC_Stop();
delay_ms(10);
return Multiple_read(0xF6);
}
//*************************************************************
u16 bmp180ReadPressure(void)
{
//u16 pressure = 0;
MPU_IIC_Start();
MPU_IIC_Send_Byte(BMP180_SlaveAddress);
while(MPU_IIC_Wait_Ack());
MPU_IIC_Send_Byte(0xF4);
while(MPU_IIC_Wait_Ack());
MPU_IIC_Send_Byte(0x34);
while(MPU_IIC_Wait_Ack());
MPU_IIC_Stop();
delay_ms(20);
return Multiple_read(0xF6);//pressure;
}
//**************************************************************
void Init_BMP180()
{
MPU_IIC_Init();
ac1 = Multiple_read(0xAA);
ac2 = Multiple_read(0xAC);
ac3 = Multiple_read(0xAE);
ac4 = Multiple_read(0xB0);
ac5 = Multiple_read(0xB2);
ac6 = Multiple_read(0xB4);
b1 = Multiple_read(0xB6);
b2 = Multiple_read(0xB8);
mb = Multiple_read(0xBA);
mc = Multiple_read(0xBC);
md = Multiple_read(0xBE);
}
//***********************************************************************
void bmp180Convert()
{
unsigned int ut;
unsigned long up;
long x1, x2, b5, b6, x3, b3, p;
unsigned long b4, b7;
ut = bmp180ReadTemp();
up = bmp180ReadPressure();
//*************
x1 = (((long)ut - (long)ac6)*(long)ac5) >> 15;
x2 = ((long) mc << 11) / (x1 + md);
b5 = x1 + x2;
result_UT = ((b5 + 8) >> 4);
//*************
b6 = b5 - 4000;
x1 = (b2 * (b6 * b6)>>12)>>11;
x2 = (ac2 * b6)>>11;
x3 = x1 + x2;
b3 = (((((long)ac1)*4 + x3)<
>2;
x1 = (ac3 * b6)>>13;
x2 = (b1 * ((b6 * b6)>>12))>>16;
x3 = ((x1 + x2) + 2)>>2;
b4 = (ac4 * (unsigned long)(x3 + 32768))>>15;
b7 = ((unsigned long)(up - b3) * (50000>>OSS));
if (b7 < 0x80000000)
p = (b7<<1)/b4;
else
p = (b7/b4)<<1;
x1 = (p>>8) * (p>>8);
x1 = (x1 * 3038)>>16;
x2 = (-7357 * p)>>16;
result_UP = p+((x1 + x2 + 3791)>>4);
}
以上内容，难免有错误与不足之处，大家踊跃拍砖。