Nick melas / MMA8451Q

no changes

Fork of MMA8451Q by Johan Kritzinger

MMA8451Q.cpp@5:2d14600116fc, 2013-03-10 (annotated)

Committer:
JoKer
Date:
Sun Mar 10 04:34:03 2013 +0000
Revision:
5:2d14600116fc
Parent:
3:db7126dbd63f
Child:
6:26a391348e7c
Added Double Tap Detection functionality

Who changed what in which revision?

UserRevisionLine numberNew contents of line
samux 1:d2630136d51e 1 /* Copyright (c) 2010-2011 mbed.org, MIT License
samux 1:d2630136d51e 2 *
samux 1:d2630136d51e 3 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
samux 1:d2630136d51e 4 * and associated documentation files (the "Software"), to deal in the Software without
samux 1:d2630136d51e 5 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
samux 1:d2630136d51e 6 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
samux 1:d2630136d51e 7 * Software is furnished to do so, subject to the following conditions:
samux 1:d2630136d51e 8 *
samux 1:d2630136d51e 9 * The above copyright notice and this permission notice shall be included in all copies or
samux 1:d2630136d51e 10 * substantial portions of the Software.
samux 1:d2630136d51e 11 *
samux 1:d2630136d51e 12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
samux 1:d2630136d51e 13 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
samux 1:d2630136d51e 14 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
samux 1:d2630136d51e 15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
samux 1:d2630136d51e 16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
samux 1:d2630136d51e 17 */
samux 1:d2630136d51e 18
emilmont 0:6149091f755d 19 #include "MMA8451Q.h"
emilmont 0:6149091f755d 20
JoKer 5:2d14600116fc 21 #define INT_SOURCE 0x0C
samux 1:d2630136d51e 22 #define REG_WHO_AM_I 0x0D
JoKer 5:2d14600116fc 23 #define HP_FILTER_CUTOFF 0x0F
JoKer 5:2d14600116fc 24 #define PULSE_CFG 0x21
JoKer 5:2d14600116fc 25 #define PULSE_SRC 0x22
JoKer 5:2d14600116fc 26 #define PULSE_THSX 0x23
JoKer 5:2d14600116fc 27 #define PULSE_THSY 0x24
JoKer 5:2d14600116fc 28 #define PULSE_THSZ 0x25
JoKer 5:2d14600116fc 29 #define PULSE_TMLT 0x26
JoKer 5:2d14600116fc 30 #define PULSE_LTCY 0x27
JoKer 5:2d14600116fc 31 #define PULSE_WIND 0x28
JoKer 5:2d14600116fc 32 #define REG_CTRL_REG_1 0x2A
JoKer 5:2d14600116fc 33 #define CTRL_REG2 0x2B
JoKer 5:2d14600116fc 34 #define CTRL_REG4 0x2D
JoKer 5:2d14600116fc 35 #define CTRL_REG5 0x2E
emilmont 0:6149091f755d 36 #define REG_OUT_X_MSB 0x01
emilmont 0:6149091f755d 37 #define REG_OUT_Y_MSB 0x03
emilmont 0:6149091f755d 38 #define REG_OUT_Z_MSB 0x05
emilmont 0:6149091f755d 39
samux 1:d2630136d51e 40 #define UINT14_MAX 16383
emilmont 0:6149091f755d 41
emilmont 0:6149091f755d 42 MMA8451Q::MMA8451Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
emilmont 0:6149091f755d 43 // activate the peripheral
emilmont 0:6149091f755d 44 uint8_t data[2] = {REG_CTRL_REG_1, 0x01};
samux 1:d2630136d51e 45 writeRegs(data, 2);
emilmont 0:6149091f755d 46 }
emilmont 0:6149091f755d 47
emilmont 0:6149091f755d 48 MMA8451Q::~MMA8451Q() { }
emilmont 0:6149091f755d 49
emilmont 0:6149091f755d 50 uint8_t MMA8451Q::getWhoAmI() {
emilmont 0:6149091f755d 51 uint8_t who_am_i = 0;
samux 1:d2630136d51e 52 readRegs(REG_WHO_AM_I, &who_am_i, 1);
emilmont 0:6149091f755d 53 return who_am_i;
emilmont 0:6149091f755d 54 }
emilmont 0:6149091f755d 55
chris 3:db7126dbd63f 56 float MMA8451Q::getAccX() {
JoKer 5:2d14600116fc 57 //divide by 4096 b/c MMA output is 4096 counts per g so this f outputs accelorometer value formatted to g (gravity)
chris 3:db7126dbd63f 58 return (float(getAccAxis(REG_OUT_X_MSB))/4096.0);
emilmont 0:6149091f755d 59 }
emilmont 0:6149091f755d 60
chris 3:db7126dbd63f 61 float MMA8451Q::getAccY() {
chris 3:db7126dbd63f 62 return (float(getAccAxis(REG_OUT_Y_MSB))/4096.0);
emilmont 0:6149091f755d 63 }
emilmont 0:6149091f755d 64
chris 3:db7126dbd63f 65 float MMA8451Q::getAccZ() {
chris 3:db7126dbd63f 66 return (float(getAccAxis(REG_OUT_Z_MSB))/4096.0);
emilmont 0:6149091f755d 67 }
emilmont 0:6149091f755d 68
chris 3:db7126dbd63f 69 void MMA8451Q::getAccAllAxis(float * res) {
emilmont 0:6149091f755d 70 res[0] = getAccX();
emilmont 0:6149091f755d 71 res[1] = getAccY();
emilmont 0:6149091f755d 72 res[2] = getAccZ();
emilmont 0:6149091f755d 73 }
emilmont 0:6149091f755d 74
emilmont 0:6149091f755d 75 int16_t MMA8451Q::getAccAxis(uint8_t addr) {
emilmont 0:6149091f755d 76 int16_t acc;
emilmont 0:6149091f755d 77 uint8_t res[2];
samux 1:d2630136d51e 78 readRegs(addr, res, 2);
emilmont 0:6149091f755d 79
emilmont 0:6149091f755d 80 acc = (res[0] << 6) | (res[1] >> 2);
emilmont 0:6149091f755d 81 if (acc > UINT14_MAX/2)
emilmont 0:6149091f755d 82 acc -= UINT14_MAX;
emilmont 0:6149091f755d 83
emilmont 0:6149091f755d 84 return acc;
emilmont 0:6149091f755d 85 }
emilmont 0:6149091f755d 86
JoKer 5:2d14600116fc 87 void MMA8451Q::setDoubleTap(void){
JoKer 5:2d14600116fc 88 //Implemented directly from Freescale's AN4072
JoKer 5:2d14600116fc 89 //Added to MMA8451Q lib
JoKer 5:2d14600116fc 90
JoKer 5:2d14600116fc 91 uint8_t CTRL_REG1_Data;
JoKer 5:2d14600116fc 92 // int adds;
JoKer 5:2d14600116fc 93 uint8_t data[2] = {REG_CTRL_REG_1, 0x08};
JoKer 5:2d14600116fc 94
JoKer 5:2d14600116fc 95 //400 Hz, Standby Mode
JoKer 5:2d14600116fc 96 writeRegs(data,2);
JoKer 5:2d14600116fc 97
JoKer 5:2d14600116fc 98 //Enable X, Y and Z Double Pulse with DPA = 0 no double pulse abort
JoKer 5:2d14600116fc 99 data[0]=PULSE_CFG;data[1]=0x2A;
JoKer 5:2d14600116fc 100 writeRegs(data,2);
JoKer 5:2d14600116fc 101
JoKer 5:2d14600116fc 102 //SetThreshold 3g on X and Y and 5g on Z
JoKer 5:2d14600116fc 103 //Note: Every step is 0.063g
JoKer 5:2d14600116fc 104 //3 g/0.063g = 48 counts
JoKer 5:2d14600116fc 105 //5g/0.063g = 79 counts
JoKer 5:2d14600116fc 106 data[0]=PULSE_THSX;data[1]=0x30;
JoKer 5:2d14600116fc 107 writeRegs(data,2);//Set X Threshold to 3g
JoKer 5:2d14600116fc 108 data[0]=PULSE_THSY;data[1]=0x30;
JoKer 5:2d14600116fc 109 writeRegs(data,2);//Set Y Threshold to 3g
JoKer 5:2d14600116fc 110 data[0]=PULSE_THSZ;data[1]=0x4F;
JoKer 5:2d14600116fc 111 writeRegs(data,2);//Set Z Threshold to 5g
JoKer 5:2d14600116fc 112
JoKer 5:2d14600116fc 113 //Set Time Limit for Tap Detection to 60 ms LP Mode
JoKer 5:2d14600116fc 114 //Note: 400 Hz ODR, Time step is 1.25 ms per step
JoKer 5:2d14600116fc 115 //60 ms/1.25 ms = 48 counts
JoKer 5:2d14600116fc 116 data[0]=PULSE_TMLT;data[1]=0x30;
JoKer 5:2d14600116fc 117 writeRegs(data,2);//60 ms
JoKer 5:2d14600116fc 118
JoKer 5:2d14600116fc 119 //Set Latency Time to 200 ms
JoKer 5:2d14600116fc 120 //Note: 400 Hz ODR LPMode, Time step is 2.5 ms per step 00 ms/2.5 ms = 80 counts
JoKer 5:2d14600116fc 121 data[0]=PULSE_LTCY;data[1]=0x50;
JoKer 5:2d14600116fc 122 writeRegs(data,2);//200 ms
JoKer 5:2d14600116fc 123
JoKer 5:2d14600116fc 124 //Set Time Window for second tap to 300 ms
JoKer 5:2d14600116fc 125 //Note: 400 Hz ODR LP Mode, Time step is 2.5 ms per step
JoKer 5:2d14600116fc 126 //300 ms/2.5 ms = 120 counts
JoKer 5:2d14600116fc 127 data[0]=PULSE_WIND;data[1]=0x78;
JoKer 5:2d14600116fc 128 writeRegs(data,2);//300 ms
JoKer 5:2d14600116fc 129
JoKer 5:2d14600116fc 130 //Route INT1 to System Interrupt
JoKer 5:2d14600116fc 131 data[0]=CTRL_REG4;data[1]=0x08;
JoKer 5:2d14600116fc 132 writeRegs(data,2);//Enable Pulse Interrupt in System CTRL_REG4
JoKer 5:2d14600116fc 133 data[0]=CTRL_REG5;data[1]=0x08;
JoKer 5:2d14600116fc 134 writeRegs(data,2);//Route Pulse Interrupt to INT1 hardware Pin CTRL_REG5
JoKer 5:2d14600116fc 135
JoKer 5:2d14600116fc 136 //Set the device to Active Mode
JoKer 5:2d14600116fc 137 readRegs(0x2A,&CTRL_REG1_Data,1);//Read out the contents of the register
JoKer 5:2d14600116fc 138 CTRL_REG1_Data |= 0x01; //Change the value in the register to Active Mode.
JoKer 5:2d14600116fc 139 data[0]=REG_CTRL_REG_1;
JoKer 5:2d14600116fc 140 data[1]=CTRL_REG1_Data;
JoKer 5:2d14600116fc 141 writeRegs(data,2);//Write in the updated value to put the device in Active Mode
JoKer 5:2d14600116fc 142 }
JoKer 5:2d14600116fc 143
JoKer 5:2d14600116fc 144
samux 1:d2630136d51e 145 void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
emilmont 0:6149091f755d 146 char t[1] = {addr};
emilmont 0:6149091f755d 147 m_i2c.write(m_addr, t, 1, true);
emilmont 0:6149091f755d 148 m_i2c.read(m_addr, (char *)data, len);
emilmont 0:6149091f755d 149 }
emilmont 0:6149091f755d 150
JoKer 5:2d14600116fc 151
JoKer 5:2d14600116fc 152
samux 1:d2630136d51e 153 void MMA8451Q::writeRegs(uint8_t * data, int len) {
emilmont 0:6149091f755d 154 m_i2c.write(m_addr, (char *)data, len);
emilmont 0:6149091f755d 155 }