MMA8491.cpp

00001 /*
00002  * Copyright (c) 2015 - 2016, Freescale Semiconductor, Inc.
00003  * Copyright 2016-2017 NXP
00004  *
00005  * Redistribution and use in source and binary forms, with or without modification,
00006  * are permitted provided that the following conditions are met:
00007  *
00008  * o Redistributions of source code must retain the above copyright notice, this list
00009  *   of conditions and the following disclaimer.
00010  *
00011  * o Redistributions in binary form must reproduce the above copyright notice, this
00012  *   list of conditions and the following disclaimer in the documentation and/or
00013  *   other materials provided with the distribution.
00014  *
00015  * o Neither the name of the copyright holder nor the names of its
00016  *   contributors may be used to endorse or promote products derived from this
00017  *   software without specific prior written permission.
00018  *
00019  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
00020  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
00021  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
00022  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
00023  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
00024  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
00025  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
00026  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
00027  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00028  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00029  */
00030 
00031 #include "MMA8491.h"
00032 #include "mbed.h"
00033 
00034 MMA8491::MMA8491(PinName sda, PinName scl, PinName en) : MMA8491_i2c(sda,scl),MMA8491_en(en)
00035  {
00036     MMA8491_en=0;
00037  }
00038     
00039  void MMA8491::acquire_MMA8491_data_g(float * a_data)
00040  {
00041   
00042    char data_bytes[7];
00043    char d[1];
00044      
00045    MMA8491_en=1;
00046    wait(0.001);
00047    d[0]=MMA8491_STATUS;
00048    MMA8491_i2c.write(MMA8491_I2C_ADDRESS,d,1,true);  
00049    MMA8491_i2c.read(MMA8491_I2C_ADDRESS,data_bytes,7);// Read the 6 data bytes - LSB and MSB for X, Y and Z Axes.
00050    MMA8491_en=0;
00051   
00052    
00053    // a_data[0]= ((float)((int16_t)data_bytes[1]));
00054    a_data[0] =  ((float)((int16_t)(((data_bytes[1]*256) + (data_bytes[2])))>> 2) * 0.0009765);
00055    a_data[1] =  ((float)((int16_t)(((data_bytes[3]*256) + (data_bytes[4])))>> 2) * 0.0009765);
00056    a_data[2] =  ((float)((int16_t)(((data_bytes[5]*256) + (data_bytes[6])))>> 2) * 0.0009765);
00057    
00058  }
00059 
00060