(二十四)树莓派3B+ Node.js驱动MPU6050
在之前的博客中写过MPU6050模块。
(十四)树莓派3B+ wiringPi库的使用–硬件IIC驱动MPU6050
之前使用的wiringPi和C语言写的，现在使用Node.js操作一下。关于电路连接和MPU6050模块的介绍，这里不做说明，大家自行查看之前的文章或者百度。
树莓派驱动MPU6050
var i2c = require('i2c-bus');
// MPU6050 寄存器
var PWR_MGMT_1 = 0x6B,
PWR_MGMT_2 = 0x6C,
SMPLRT_DIV = 0x19;
var CONFIG = 0x1A,
GYRO_CONFIG = 0x1B,
ACCEL_CONFIG = 0x1C,
INT_ENABLE = 0x38;
// 加速度 16位数据 低8位是在高8位的基础上地址 +1
var ACCEL_XOUT_H = 0x3B,
ACCEL_YOUT_H = 0x3D,
ACCEL_ZOUT_H = 0x3F;
// 角速度 16位数据 低8位是在高8位的基础上地址 +1
var GYRO_XOUT_H = 0x43,
GYRO_YOUT_H = 0x45,
GYRO_ZOUT_H = 0x47;
// 当前温度寄存器
var TEMP_OUT = 0x41;
// 加速度计和陀螺仪输出值和实际值的换算比例 输出值/比例 = 实际值
var ACCEL_LSB_SENSITIVITY = 16384.0, // 加速度计 16384LSB/g
GYRO_LSB_SENSITIVITY = 16.4; // 陀螺仪 16.4LSB%s
// ±2g ±4g ±8g ±16g
//16384 8192 4096 2048 LSB/g
// ±250%s ±500%s ±1000%s ±2000%s
// 131 65.5 32.8 16.4 LSB%s
function mpu6050( i2cbus, mpuaddress ) {
if (!(this instanceof mpu6050)) {
return new mpu6050(i2cbus, mpuaddress);
}
this.address = mpuaddress;
this.bus = i2c.openSync(i2cbus);
// 内部20MHz时钟源 开启温度检测 关闭休眠
this.bus.writeByteSync(this.address, PWR_MGMT_1, 0);
// 采样分分频率
// SAMPLE_RATE = INTERNAL_SAMPLE_RATE / (1 + SMPLRT_DIV) where INTERNAL_SAMPLE_RATE = 1kHz
this.bus.writeByteSync(this.address, SMPLRT_DIV, 7); // 125Hz
// 正常工作模式
this.bus.writeByteSync(this.address, PWR_MGMT_2, 0);
this.bus.writeByteSync(this.address, CONFIG, 0);
// 陀螺仪设置 不自检 ±2000dps
this.bus.writeByteSync(this.address, GYRO_CONFIG, 24); // 24 --> 0x18
// 加速度计设置 不自检 ±2g
this.bus.writeByteSync(this.address, ACCEL_CONFIG, 0);
// 数据就绪中断
this.bus.writeByteSync(this.address, INT_ENABLE, 1);
}
// i2c读取mpu6050原始数据
mpu6050.prototype.read_raw_data = function (addr) {
var high = this.bus.readByteSync(this.address, addr);
var low = this.bus.readByteSync(this.address, addr+1);
var value = (high << 8) + low; // 高8位 左移8位 组装成16位的数据
if (value > 32768) {
value = value - 65536;
}
return value;
};
// 读取温度值
mpu6050.prototype.get_temp = function() {
var value = this.read_raw_data(TEMP_OUT);
var temp = 36.53 + value/340.0; // 输出 ℃
var mpu6050_temp = {
temp:temp
}
return mpu6050_temp;
}
// 读取角速度值
mpu6050.prototype.get_gyro_xyz = function() {
var x = this.read_raw_data(GYRO_XOUT_H);
var y = this.read_raw_data(GYRO_YOUT_H);
var z = this.read_raw_data(GYRO_ZOUT_H);
var gyro_xyz = {
x:x,
y:y,
z:z
}
return gyro_xyz;
}
// 读取加速度值
mpu6050.prototype.get_accel_xyz = function() {
var x = this.read_raw_data(ACCEL_XOUT_H);
var y = this.read_raw_data(ACCEL_YOUT_H);
var z = this.read_raw_data(ACCEL_ZOUT_H);
var accel_xyz = {
x:x,
y:y,
z:z
}
return accel_xyz;
}
mpu6050.prototype.get_roll_pitch_yaw = function( gyro_xyz, accel_xyz ) {
var Ax = accel_xyz.x/ACCEL_LSB_SENSITIVITY;
var Ay = accel_xyz.y/ACCEL_LSB_SENSITIVITY;
var Az = accel_xyz.z/ACCEL_LSB_SENSITIVITY;
var roll = Ax*-100;
var pitch = Ay*-100;
var yaw = Az*100; // 这个是有问题的
var roll_pitch_yaw = {
roll: roll, // 横滚角
pitch: pitch, // 俯仰角
yaw: yaw // 航向角
}
return roll_pitch_yaw;
}
// 获取MPU6050数据
mpu6050.prototype.get_mpu6050Data = function( gyro_xyz, accel_xyz ) {
var gyro_xyz = this.get_gyro_xyz();
var accel_xyz = this.get_accel_xyz();
var temp = this.get_temp();
var roll_pitch_yaw = this.get_roll_pitch_yaw(gyro_xyz,accel_xyz);
var mpu6050Data = {
gyro_xyz: gyro_xyz,
accel_xyz: accel_xyz,
temp: temp,
roll_pitch_yaw: roll_pitch_yaw,
}
return mpu6050Data;
}
module.exports = mpu6050;
测试代码
var mpu6050 = require("./mpu6050");
var rpio = require('rpio'); // 引入rpio这个库 为了使用他的延时函数
var address = 0x68; //MPU6050 address
var bus = 1; //i2c bus used
var mpu6050 = new mpu6050( bus,address );
function update_telemetry() {
var mpu6050Data = mpu6050.get_mpu6050Data();
console.log(mpu6050Data);
return mpu6050Data;
}
if ( mpu6050 ) {
while(true){
update_telemetry();
rpio.msleep(100);
}
}
输出结果
{
gyro_xyz: {
x: -20, y: 39, z: -22 },
accel_xyz: {
x: -112, y: -76, z: 17088 },
temp: {
temp: 31.353529411764708 },
roll_pitch_yaw: {
roll: 0.68359375, pitch: 0.4638671875, yaw: 104.296875 }
}