1.概述
MMA8452Q是一款具有 12位分辨率的智能低功耗、三轴、电容式微机械加速度传感器。这款加速度传感器具有丰富嵌入式功能，带有灵活的用户可编程选项，可以配置多达两个中断引脚。嵌入式中断功能可以节省整体功耗，解除主处理器不断轮询数据的负担。MMA8452Q 具有±2g/±4g/±8g的用户可选量程，可以实时输出高通滤波数据和非滤波数据。该器件可配置嵌入式的功能生成惯性唤醒中断信号，这就使MMA8452Q 在监控事件同时，在静止状态保持低功耗模式。
为了方面接线，我们还配送1根4pin线，线的一端为白色防反插接口（和传感器上防反插白色端子匹配），另一端为4pin杜邦线母头接口。
该传感器兼容各种单片机控制板，如arduino系列单片机。使用时，我们可以在单片机上堆叠一个传感器扩展板。传感器和自带导线连接，然后连接在传感器扩展板上，简单方便。同时，传感器自带2个直径为3mm的定位孔，方便你将传感器固定在其他设备。
2.规格参数
导线长度：200mm
工作电压: DC 3.3-5V
±2g/±4g/±8g 动态量程可选
输出数据速率 (ODR) 范围： 1.56 Hz 至 800 Hz
噪声：99μg/√Hz
12位和 8位数字输出
I2C 数字输出接口（在上拉电阻为4.7 kΩ 时，最高频率可达2.25 MHz）
适用于 6个中断来源的 2个可编程中断引脚
3 个运动检测嵌入式通道： 自由落体检测， 脉冲检测， 晃动检测。
带有设定滞后补偿的方向（横向/纵向）检测
自动唤醒和自动休眠的ODR可自动更改
高通滤波数据可实时输出
功耗： 6 μA – 165 μA
尺寸：131*22*14mm
重量：5.1g
3.连接图
4.测试代码
特别注意：在烧录程序前，要把Wire和SparkFun_MMA8452Q_Arduino_Library_master文件夹放到 编译器安装目录下的\Arduino\libraries里。不然编译不过。例如我的：C:\Program Files\Arduino\libraries
#include <Wire.h> // Must include Wire library for I2C
#include <SparkFun_MMA8452Q.h> // Includes the SFE_MMA8452Q library
// Begin using the library by creating an instance of the MMA8452Q
// class. We’ll call it “accel”. That’s what we’ll reference from
// here on out.
MMA8452Q accel;
// The setup function simply starts serial and initializes the
// accelerometer.
void setup()
{
Serial.begin(9600);
Serial.println(“MMA8452Q Test Code!”);
// Choose your adventure! There are a few options when it comes
// to initializing the MMA8452Q:
// 1. Default init. This will set the accelerometer up
// with a full-scale range of +/-2g, and an output data rate
// of 800 Hz (fastest).
accel.init();
// 2. Initialize with FULL-SCALE setting. You can set the scale
// using either SCALE_2G, SCALE_4G, or SCALE_8G as the value.
// That’ll set the scale to +/-2g, 4g, or 8g respectively.
//accel.init(SCALE_4G); // Uncomment this out if you’d like
// 3. Initialize with FULL-SCALE and DATA RATE setting. If you
// want control over how fast your accelerometer produces
// data use one of the following options in the second param:
// ODR_800, ODR_400, ODR_200, ODR_100, ODR_50, ODR_12,
// ODR_6, or ODR_1.
// Sets to 800, 400, 200, 100, 50, 12.5, 6.25, or 1.56 Hz.
//accel.init(SCALE_8G, ODR_6);
}
// The loop function will simply check for new data from the
// accelerometer and print it out if it’s available.
void loop()
{
// Use the accel.available() function to wait for new data
// from the accelerometer.
if (accel.available())
{
// First, use accel.read() to read the new variables:
accel.read();
// accel.read() will update two sets of variables.
// * int’s x, y, and z will store the signed 12-bit values
// read out of the accelerometer.
// * floats cx, cy, and cz will store the calculated
// acceleration from those 12-bit values. These variables
// are in units of g’s.
// Check the two function declarations below for an example
// of how to use these variables.
printCalculatedAccels();
//printAccels(); // Uncomment to print digital readings
// The library also supports the portrait/landscape detection
// of the MMA8452Q. Check out this function declaration for
// an example of how to use that.
printOrientation();
Serial.println(); // Print new line every time.
}
}
// The function demonstrates how to use the accel.x, accel.y and
// accel.z variables.
// Before using these variables you must call the accel.read()
// function!
void printAccels()
{
Serial.print(accel.x, 3);
Serial.print(“\t”);
Serial.print(accel.y, 3);
Serial.print(“\t”);
Serial.print(accel.z, 3);
Serial.print(“\t”);
}
// This function demonstrates how to use the accel.cx, accel.cy,
// and accel.cz variables.
// Before using these variables you must call the accel.read()
// function!
void printCalculatedAccels()
{
Serial.print(accel.cx, 3);
Serial.print(“\t”);
Serial.print(accel.cy, 3);
Serial.print(“\t”);
Serial.print(accel.cz, 3);
Serial.print(“\t”);
}
// This function demonstrates how to use the accel.readPL()
// function, which reads the portrait/landscape status of the
// sensor.
void printOrientation()
{
// accel.readPL() will return a byte containing information
// about the orientation of the sensor. It will be either
// PORTRAIT_U, PORTRAIT_D, LANDSCAPE_R, LANDSCAPE_L, or
// LOCKOUT.
byte pl = accel.readPL();
switch (pl)
{
case PORTRAIT_U:
Serial.print(“Portrait Up”);
break;
case PORTRAIT_D:
Serial.print(“Portrait Down”);
break;
case LANDSCAPE_R:
Serial.print(“Landscape Right”);
break;
case LANDSCAPE_L:
Serial.print(“Landscape Left”);
break;
case LOCKOUT:
Serial.print(“Flat”);
break;
}
}
5.测试结果
烧录好测试代码，按照接线图连接好线，利用USB线上电后，打开软件串口监视器，设置波特率为9600。串口监视器显示当传感器三轴加速度以及传感器放置状态，如下图。
6.库文件链接
https://pan.baidu.com/s/1T9OcteO0x1sBxlxTPxffxQ
提取码：b7qk