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姿态传感器 MPU9250
姿态传感器 MPU9250 是一款多芯片模块,集成两个芯片,一个芯片是 MPU6500,由 3 轴陀螺仪和 3 轴加速度计组成,另外一个是 AK8963 是 3 轴磁力计
注意: 在使用前应使用
MPU9250 IMU 创建实体initMPU9250()
功能:
初始化 MPU6500 芯片
函数原型:
void initMPU9250()
使用示例:
#include <M5Stack.h>
#include "utility/MPU9250.h"
MPU9250 IMU; // new a MPU9250 object
void setup(){
M5.begin();
Serial.begin(115200);
IMU.initMPU9250();
byte c = IMU.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250);
Serial.print("MPU9250 "); Serial.print("I AM "); Serial.print(c, HEX);
}
initAK8963()
功能:
初始化 AK8963 芯片
函数原型:
void initAK8963(float * destination)
| 参数 | 描述 |
|---|---|
| destination | 出厂预设于 AK8963 芯片内缺省值的数组指针 |
使用示例:
#include <M5Stack.h>
#include "utility/MPU9250.h"
MPU9250 IMU; // new a MPU9250 object
void setup(){
M5.begin();
Serial.begin(115200);
// "magCalibration[3] = {0};" was defined at file "MPU9250.h"
IMU.initAK8963(IMU.magCalibration);
Serial.println("AK8963 initialized for active data mode....");
if (Serial)
{
// Serial.println("Calibration values: ");
Serial.print("X-Axis sensitivity adjustment value ");
Serial.println(IMU.magCalibration[0], 2);
Serial.print("Y-Axis sensitivity adjustment value ");
Serial.println(IMU.magCalibration[1], 2);
Serial.print("Z-Axis sensitivity adjustment value ");
Serial.println(IMU.magCalibration[2], 2);
}
}
calibrateMPU9250()
功能:
初始化芯片后,执行该函数以读取静止状态下的陀螺仪和加速度值偏移,并保存到各自的偏移寄存器
函数原型:
void calibrateMPU9250(float * gyroBias, float * accelBias)
| 参数 | 描述 |
|---|---|
| gyroBias | 保存静止下陀螺仪值的数组的地址 |
| accelBias | 保存静止下加速度值的数组的地址 |
使用示例:
#include <M5Stack.h>
#include "utility/MPU9250.h"
MPU9250 IMU; // new a MPU9250 object
void setup(){
M5.begin();
Serial.begin(115200);
IMU.initMPU9250();
byte c = IMU.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250);
Serial.print("MPU9250 "); Serial.print("I AM "); Serial.print(c, HEX);
// "gyroBias[3] = {0};" was defined at file "MPU9250.h"
// "accelBias[3] = {0};" was defined at file "MPU9250.h"
IMU.calibrateMPU9250(IMU.gyroBias, IMU.accelBias);
M5.Lcd.fillScreen(BLACK);
M5.Lcd.setTextSize(1);
M5.Lcd.setCursor(0, 0); M5.Lcd.print("MPU9250 bias");
M5.Lcd.setCursor(0, 16); M5.Lcd.print(" x y z ");
M5.Lcd.setCursor(0, 32); M5.Lcd.print((int)(1000*IMU.accelBias[0]));
M5.Lcd.setCursor(32, 32); M5.Lcd.print((int)(1000*IMU.accelBias[1]));
M5.Lcd.setCursor(64, 32); M5.Lcd.print((int)(1000*IMU.accelBias[2]));
M5.Lcd.setCursor(96, 32); M5.Lcd.print("mg");
M5.Lcd.setCursor(0, 48); M5.Lcd.print(IMU.gyroBias[0], 1);
M5.Lcd.setCursor(32, 48); M5.Lcd.print(IMU.gyroBias[1], 1);
M5.Lcd.setCursor(64, 48); M5.Lcd.print(IMU.gyroBias[2], 1);
M5.Lcd.setCursor(96, 48); M5.Lcd.print("o/s");
}
void loop(){
}
readByte()
功能:
读取指定寄存器内数据返回值:寄存器值,长度为8位
函数原型:
uint8_t readByte(uint8_t address, uint8_t subAddress)
| 参数 | 描述 |
|---|---|
| address | 芯片 (MPU9250/AK8963)地址 |
| subAddress | 芯片内寄存器地址 |
使用示例:
#include <M5Stack.h>
#include "utility/MPU9250.h"
MPU9250 IMU; // new a MPU9250 object
void setup(){
M5.begin();
Serial.begin(115200);
byte c = IMU.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250);
Serial.print("MPU9250 "); Serial.print("I AM "); Serial.print(c, HEX);
}
readGyroData()
功能:
读取三个方向的陀螺仪值
函数原型:
void readGyroData(int16_t * destination)
| 参数 | 描述 |
|---|---|
| destination | 保存陀螺仪值的数组的地址 |
使用示例:
#include <M5Stack.h>
#include "utility/MPU9250.h"
MPU9250 IMU; // new a MPU9250 object
void setup(){
M5.begin();
Serial.begin(115200);
IMU.initMPU9250();
byte c = IMU.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250);
Serial.print("MPU9250 "); Serial.print("I AM "); Serial.print(c, HEX);
IMU.calibrateMPU9250(IMU.gyroBias, IMU.accelBias);
}
void loop(){
// If intPin goes high, all data registers have new data
// On interrupt, check if data ready interrupt
if (IMU.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01)
{
// "gyroCount[3] = {0};" was defined at file "MPU9250.h"
IMU.readGyroData(IMU.gyroCount); // Read the x/y/z adc values
IMU.getGres(); // get Gyro scales saved to "gRes"
IMU.gx = (float)IMU.gyroCount[0]*IMU.gRes;
IMU.gy = (float)IMU.gyroCount[1]*IMU.gRes;
IMU.gz = (float)IMU.gyroCount[2]*IMU.gRes;
Serial.print("X-gyro rate: "); Serial.print(IMU.gx, 3);
Serial.print(" degrees/sec ");
Serial.print("Y-gyro rate: "); Serial.print(IMU.gy, 3);
Serial.print(" degrees/sec ");
Serial.print("Z-gyro rate: "); Serial.print(IMU.gz, 3);
Serial.println(" degrees/sec");
}
}
readAccelData()
功能:
读取三个方向的加速度值
函数原型:
void readAccelData(int16_t * destination)
| 参数 | 描述 |
|---|---|
| destination | 保存加速度值的数组的地址 |
使用示例:
#include <M5Stack.h>
#include "utility/MPU9250.h"
MPU9250 IMU; // new a MPU9250 object
void setup(){
M5.begin();
Serial.begin(115200);
IMU.initMPU9250();
byte c = IMU.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250);
Serial.print("MPU9250 "); Serial.print("I AM "); Serial.print(c, HEX);
IMU.calibrateMPU9250(IMU.gyroBias, IMU.accelBias);
}
void loop(){
// If intPin goes high, all data registers have new data
// On interrupt, check if data ready interrupt
if (IMU.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01)
{
// "accelCount[3] = {0};" was defined at file "MPU9250.h"
IMU.readAccelData(IMU.accelCount);
IMU.getAres(); // get accelerometer scales saved to "aRes"
IMU.ax = (float)IMU.accelCount[0]*IMU.aRes; // - accelBias[0];
IMU.ay = (float)IMU.accelCount[1]*IMU.aRes; // - accelBias[1];
IMU.az = (float)IMU.accelCount[2]*IMU.aRes; // - accelBias[2];
Serial.print("X-acceleration: "); Serial.print(1000*IMU.ax);
Serial.print(" mg ");
Serial.print("Y-acceleration: "); Serial.print(1000*IMU.ay);
Serial.print(" mg ");
Serial.print("Z-acceleration: "); Serial.print(1000*IMU.az);
Serial.println(" mg ");
}
}
readTempData()
功能:
读取温度
函数原型:
int16_t readTempData(void)
使用示例:
#include <M5Stack.h>
#include "utility/MPU9250.h"
MPU9250 IMU; // new a MPU9250 object
void setup()
{
M5.begin();
Wire.begin();
IMU.calibrateMPU9250(IMU.gyroBias, IMU.accelBias);
IMU.initMPU9250();
IMU.initAK8963(IMU.magCalibration);
}
void loop()
{
IMU.tempCount = IMU.readTempData();
IMU.temperature = ((float) IMU.tempCount) / 333.87 + 21.0;
M5.Lcd.setCursor(0, 0);
M5.Lcd.print("MPU9250 Temperature is ");
M5.Lcd.print(IMU.temperature, 1);
delay(500);
}