MMA8451Q.cpp

00001 /* Copyright (c) 2010-2011 mbed.org, MIT License
00002 *
00003 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
00004 * and associated documentation files (the "Software"), to deal in the Software without
00005 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
00006 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
00007 * Software is furnished to do so, subject to the following conditions:
00008 *
00009 * The above copyright notice and this permission notice shall be included in all copies or
00010 * substantial portions of the Software.
00011 *
00012 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
00013 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00014 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
00015 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00016 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00017 */
00018 
00019 
00020 
00021 #include "MMA8451Q.h"
00022 
00023 #define REG_WHO_AM_I      0x0D
00024 #define REG_CTRL_REG_1    0x2A
00025 #define REG_OUT_X_MSB     0x01
00026 #define REG_OUT_Y_MSB     0x03
00027 #define REG_OUT_Z_MSB     0x05
00028 #define XYZ_DATA_CFG      0x0E
00029 
00030 #define UINT14_MAX        16383
00031 
00032 #define MAX_2G            0x00
00033 #define MAX_4G            0X01
00034 #define MAX_8G            0X10
00035 
00036 #define GSCALING          1024.0
00037 
00038 MMA8451Q::MMA8451Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
00039     // activate the peripheral
00040     uint8_t data[2] = {REG_CTRL_REG_1, 0x01};
00041     writeRegs(data, 2);
00042 }
00043 
00044 void MMA8451Q::setGLImit()
00045 {
00046     uint8_t data[2] = {REG_CTRL_REG_1, 0x00};
00047     writeRegs(data, 2); //put in standby
00048     data[0] = XYZ_DATA_CFG;
00049     data[1] = 0x02;
00050     writeRegs(data, 2);
00051     data[0] = REG_CTRL_REG_1;
00052     data[1] = 0x01;
00053     writeRegs(data, 2); //make active
00054 }
00055 
00056 MMA8451Q::~MMA8451Q() { }
00057 
00058 //uint8_t MMA8451Q::getGLimit(uint8_t regData) 
00059 //{
00060 //    acc.getGLimit();
00061 //    acc.readRegs(XYZ_DATA_CFG, &regData, 1);
00062 //    sprintf(lcdData, "%d", regData);
00063 //    LCDMess(lcdData, BLINKTIME);
00064 //    acc.readRegs(REG_WHO_AM_I, &regData, 1);
00065 //    springf(lcdData, "%d", regData);
00066 //    LCDMess(lcdData, BLINKTIME);
00067 //    
00068 //    return regDate
00069 //}
00070 
00071 uint8_t MMA8451Q::getWhoAmI() {
00072     uint8_t who_am_i = 0;
00073     readRegs(REG_WHO_AM_I, &who_am_i, 1);
00074     return who_am_i;
00075 }
00076 
00077 float MMA8451Q::getAccX() {
00078     return (float(getAccAxis(REG_OUT_X_MSB))/4096.0);
00079 }
00080 
00081 float MMA8451Q::getAccY() {
00082     return (float(getAccAxis(REG_OUT_Y_MSB))/4096.0);
00083 }
00084 
00085 float MMA8451Q::getAccZ() {
00086     return (float(getAccAxis(REG_OUT_Z_MSB))/4096.0);
00087 }
00088 
00089 void MMA8451Q::getAccAllAxis(float * res) {
00090     res[0] = getAccX();
00091     res[1] = getAccY();
00092     res[2] = getAccZ();
00093 }
00094 
00095 int16_t MMA8451Q::getAccAxis(uint8_t addr) {
00096     int16_t acc;
00097     uint8_t res[2];
00098     readRegs(addr, res, 2);
00099 
00100     acc = (res[0] << 6) | (res[1] >> 2); 
00101     if (acc > UINT14_MAX/2)
00102         acc -= UINT14_MAX;
00103 
00104     return acc;
00105 }
00106 
00107 void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
00108     char t[1] = {addr};
00109     m_i2c.write(m_addr, t, 1, true);
00110     m_i2c.read(m_addr, (char *)data, len);
00111 }
00112 
00113 void MMA8451Q::writeRegs(uint8_t * data, int len) {
00114     m_i2c.write(m_addr, (char *)data, len);
00115 }