JP PANG / MMA8491Q

modified from MMA8451Q

Dependents:   XtrinsicSensorEVK SDFileSystem_HelloWorld5_copy xtrinsic_sensors

MMA8491Q.cpp@0:41db55eef564, 2013-10-10 (annotated)

Committer:
jppang
Date:
Thu Oct 10 03:20:44 2013 +0000
Revision:
0:41db55eef564
Child:
1:2d4b7fadb1e6
modified from MMA8451Q

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jppang 0:41db55eef564 1 /* Copyright (c) 2010-2011 mbed.org, MIT License
jppang 0:41db55eef564 2 *
jppang 0:41db55eef564 3 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
jppang 0:41db55eef564 4 * and associated documentation files (the "Software"), to deal in the Software without
jppang 0:41db55eef564 5 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
jppang 0:41db55eef564 6 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
jppang 0:41db55eef564 7 * Software is furnished to do so, subject to the following conditions:
jppang 0:41db55eef564 8 *
jppang 0:41db55eef564 9 * The above copyright notice and this permission notice shall be included in all copies or
jppang 0:41db55eef564 10 * substantial portions of the Software.
jppang 0:41db55eef564 11 *
jppang 0:41db55eef564 12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
jppang 0:41db55eef564 13 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
jppang 0:41db55eef564 14 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
jppang 0:41db55eef564 15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
jppang 0:41db55eef564 16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
jppang 0:41db55eef564 17 */
jppang 0:41db55eef564 18
jppang 0:41db55eef564 19 #include "MMA8491Q.h"
jppang 0:41db55eef564 20
jppang 0:41db55eef564 21 #define INT_SOURCE 0x0C
jppang 0:41db55eef564 22 #define REG_WHO_AM_I 0x0D
jppang 0:41db55eef564 23 #define HP_FILTER_CUTOFF 0x0F
jppang 0:41db55eef564 24 #define PULSE_CFG 0x21
jppang 0:41db55eef564 25 #define PULSE_SRC 0x22
jppang 0:41db55eef564 26 #define PULSE_THSX 0x23
jppang 0:41db55eef564 27 #define PULSE_THSY 0x24
jppang 0:41db55eef564 28 #define PULSE_THSZ 0x25
jppang 0:41db55eef564 29 #define PULSE_TMLT 0x26
jppang 0:41db55eef564 30 #define PULSE_LTCY 0x27
jppang 0:41db55eef564 31 #define PULSE_WIND 0x28
jppang 0:41db55eef564 32 #define REG_CTRL_REG_1 0x2A
jppang 0:41db55eef564 33 #define CTRL_REG2 0x2B
jppang 0:41db55eef564 34 #define CTRL_REG4 0x2D
jppang 0:41db55eef564 35 #define CTRL_REG5 0x2E
jppang 0:41db55eef564 36 #define REG_OUT_X_MSB 0x01
jppang 0:41db55eef564 37 #define REG_OUT_Y_MSB 0x03
jppang 0:41db55eef564 38 #define REG_OUT_Z_MSB 0x05
jppang 0:41db55eef564 39
jppang 0:41db55eef564 40 #define UINT14_MAX 16383
jppang 0:41db55eef564 41
jppang 0:41db55eef564 42 MMA8491Q::MMA8491Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
jppang 0:41db55eef564 43 // activate the peripheral
jppang 0:41db55eef564 44 uint8_t data[2] = {REG_CTRL_REG_1, 0x01};
jppang 0:41db55eef564 45 writeRegs(data, 2);
jppang 0:41db55eef564 46 }
jppang 0:41db55eef564 47
jppang 0:41db55eef564 48 MMA8491Q::~MMA8491Q() { }
jppang 0:41db55eef564 49
jppang 0:41db55eef564 50 uint8_t MMA8491Q::getWhoAmI() {
jppang 0:41db55eef564 51 uint8_t who_am_i = 0;
jppang 0:41db55eef564 52 readRegs(REG_WHO_AM_I, &who_am_i, 1);
jppang 0:41db55eef564 53 return who_am_i;
jppang 0:41db55eef564 54 }
jppang 0:41db55eef564 55
jppang 0:41db55eef564 56 float MMA8491Q::getAccX() {
jppang 0:41db55eef564 57 //divide by 4096 b/c MMA output is 4096 counts per g so this f outputs accelorometer value formatted to g (gravity)
jppang 0:41db55eef564 58 return (float(getAccAxis(REG_OUT_X_MSB))*4.0/4096.0);
jppang 0:41db55eef564 59 }
jppang 0:41db55eef564 60
jppang 0:41db55eef564 61 float MMA8491Q::getAccY() {
jppang 0:41db55eef564 62 return (float(getAccAxis(REG_OUT_Y_MSB))*4.0/4096.0);
jppang 0:41db55eef564 63 }
jppang 0:41db55eef564 64
jppang 0:41db55eef564 65 float MMA8491Q::getAccZ() {
jppang 0:41db55eef564 66 return (float(getAccAxis(REG_OUT_Z_MSB))*4.0/4096.0);
jppang 0:41db55eef564 67 }
jppang 0:41db55eef564 68
jppang 0:41db55eef564 69 void MMA8491Q::getAccAllAxis(float * res) {
jppang 0:41db55eef564 70 res[0] = getAccX();
jppang 0:41db55eef564 71 res[1] = getAccY();
jppang 0:41db55eef564 72 res[2] = getAccZ();
jppang 0:41db55eef564 73 }
jppang 0:41db55eef564 74
jppang 0:41db55eef564 75 int16_t MMA8491Q::getAccAxis(uint8_t addr) {
jppang 0:41db55eef564 76 int16_t acc;
jppang 0:41db55eef564 77 uint8_t res[2];
jppang 0:41db55eef564 78 readRegs(addr, res, 2);
jppang 0:41db55eef564 79
jppang 0:41db55eef564 80 acc = (res[0] << 6) | (res[1] >> 2);
jppang 0:41db55eef564 81 if (acc > UINT14_MAX/2)
jppang 0:41db55eef564 82 acc -= UINT14_MAX;
jppang 0:41db55eef564 83
jppang 0:41db55eef564 84 return acc;
jppang 0:41db55eef564 85 }
jppang 0:41db55eef564 86
jppang 0:41db55eef564 87 void MMA8491Q::setDoubleTap(void){
jppang 0:41db55eef564 88 //Implemented directly from Freescale's AN4072
jppang 0:41db55eef564 89 //Added to MMA8491Q lib
jppang 0:41db55eef564 90
jppang 0:41db55eef564 91 uint8_t CTRL_REG1_Data;
jppang 0:41db55eef564 92 // int adds;
jppang 0:41db55eef564 93 uint8_t data[2] = {REG_CTRL_REG_1, 0x08};
jppang 0:41db55eef564 94
jppang 0:41db55eef564 95 //400 Hz, Standby Mode
jppang 0:41db55eef564 96 writeRegs(data,2);
jppang 0:41db55eef564 97
jppang 0:41db55eef564 98 //Enable X, Y and Z Double Pulse with DPA = 0 no double pulse abort
jppang 0:41db55eef564 99 data[0]=PULSE_CFG;data[1]=0x2A;
jppang 0:41db55eef564 100 writeRegs(data,2);
jppang 0:41db55eef564 101
jppang 0:41db55eef564 102 //SetThreshold 3g on X and Y and 5g on Z
jppang 0:41db55eef564 103 //Note: Every step is 0.063g
jppang 0:41db55eef564 104 //3 g/0.063g = 48 counts
jppang 0:41db55eef564 105 //5g/0.063g = 79 counts
jppang 0:41db55eef564 106 data[0]=PULSE_THSX;data[1]=0x30;
jppang 0:41db55eef564 107 writeRegs(data,2);//Set X Threshold to 3g
jppang 0:41db55eef564 108 data[0]=PULSE_THSY;data[1]=0x30;
jppang 0:41db55eef564 109 writeRegs(data,2);//Set Y Threshold to 3g
jppang 0:41db55eef564 110 data[0]=PULSE_THSZ;data[1]=0x4F;
jppang 0:41db55eef564 111 writeRegs(data,2);//Set Z Threshold to 5g
jppang 0:41db55eef564 112
jppang 0:41db55eef564 113 //Set Time Limit for Tap Detection to 60 ms LP Mode
jppang 0:41db55eef564 114 //Note: 400 Hz ODR, Time step is 1.25 ms per step
jppang 0:41db55eef564 115 //60 ms/1.25 ms = 48 counts
jppang 0:41db55eef564 116 data[0]=PULSE_TMLT;data[1]=0x30;
jppang 0:41db55eef564 117 writeRegs(data,2);//60 ms
jppang 0:41db55eef564 118
jppang 0:41db55eef564 119 //Set Latency Time to 200 ms
jppang 0:41db55eef564 120 //Note: 400 Hz ODR LPMode, Time step is 2.5 ms per step 00 ms/2.5 ms = 80 counts
jppang 0:41db55eef564 121 data[0]=PULSE_LTCY;data[1]=0x50;
jppang 0:41db55eef564 122 writeRegs(data,2);//200 ms
jppang 0:41db55eef564 123
jppang 0:41db55eef564 124 //Set Time Window for second tap to 300 ms
jppang 0:41db55eef564 125 //Note: 400 Hz ODR LP Mode, Time step is 2.5 ms per step
jppang 0:41db55eef564 126 //300 ms/2.5 ms = 120 counts
jppang 0:41db55eef564 127 data[0]=PULSE_WIND;data[1]=0x78;
jppang 0:41db55eef564 128 writeRegs(data,2);//300 ms
jppang 0:41db55eef564 129
jppang 0:41db55eef564 130 //Route INT1 to System Interrupt
jppang 0:41db55eef564 131 data[0]=CTRL_REG4;data[1]=0x08;
jppang 0:41db55eef564 132 writeRegs(data,2);//Enable Pulse Interrupt in System CTRL_REG4
jppang 0:41db55eef564 133 data[0]=CTRL_REG5;data[1]=0x08;
jppang 0:41db55eef564 134 writeRegs(data,2);//Route Pulse Interrupt to INT1 hardware Pin CTRL_REG5
jppang 0:41db55eef564 135
jppang 0:41db55eef564 136 //Set the device to Active Mode
jppang 0:41db55eef564 137 readRegs(0x2A,&CTRL_REG1_Data,1);//Read out the contents of the register
jppang 0:41db55eef564 138 CTRL_REG1_Data |= 0x01; //Change the value in the register to Active Mode.
jppang 0:41db55eef564 139 data[0]=REG_CTRL_REG_1;
jppang 0:41db55eef564 140 data[1]=CTRL_REG1_Data;
jppang 0:41db55eef564 141 writeRegs(data,2);//Write in the updated value to put the device in Active Mode
jppang 0:41db55eef564 142 }
jppang 0:41db55eef564 143
jppang 0:41db55eef564 144
jppang 0:41db55eef564 145 void MMA8491Q::readRegs(int addr, uint8_t * data, int len) {
jppang 0:41db55eef564 146 char t[1] = {addr};
jppang 0:41db55eef564 147 m_i2c.write(m_addr, t, 1, true);
jppang 0:41db55eef564 148 m_i2c.read(m_addr, (char *)data, len);
jppang 0:41db55eef564 149 }
jppang 0:41db55eef564 150
jppang 0:41db55eef564 151
jppang 0:41db55eef564 152
jppang 0:41db55eef564 153 void MMA8491Q::writeRegs(uint8_t * data, int len) {
jppang 0:41db55eef564 154 m_i2c.write(m_addr, (char *)data, len);
jppang 0:41db55eef564 155 }