Junaid Ahmed / Mbed 2 deprecated 202A_hw1_maxrate

Generate the maximum sampling rate

Dependencies:   MAG31101 mbed

MMA8451Q/MMA8451Q.cpp@1:478b36058c92, 2014-02-15 (annotated)

Committer:
mja054
Date:
Sat Feb 15 01:07:15 2014 +0000
Revision:
1:478b36058c92
Parent:
0:d62b58e30f71 
Generate the maximum sampling rate

Who changed what in which revision?

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mja054 0:d62b58e30f71 1 /* Copyright (c) 2010-2011 mbed.org, MIT License
mja054 0:d62b58e30f71 2 *
mja054 0:d62b58e30f71 3 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
mja054 0:d62b58e30f71 4 * and associated documentation files (the "Software"), to deal in the Software without
mja054 0:d62b58e30f71 5 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
mja054 0:d62b58e30f71 6 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
mja054 0:d62b58e30f71 7 * Software is furnished to do so, subject to the following conditions:
mja054 0:d62b58e30f71 8 *
mja054 0:d62b58e30f71 9 * The above copyright notice and this permission notice shall be included in all copies or
mja054 0:d62b58e30f71 10 * substantial portions of the Software.
mja054 0:d62b58e30f71 11 *
mja054 0:d62b58e30f71 12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
mja054 0:d62b58e30f71 13 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
mja054 0:d62b58e30f71 14 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
mja054 0:d62b58e30f71 15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
mja054 0:d62b58e30f71 16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
mja054 0:d62b58e30f71 17 */
mja054 0:d62b58e30f71 18
mja054 0:d62b58e30f71 19 #include "MMA8451Q.h"
mja054 0:d62b58e30f71 20
mja054 0:d62b58e30f71 21 #define INT_SOURCE 0x0C
mja054 0:d62b58e30f71 22 #define REG_WHO_AM_I 0x0D
mja054 0:d62b58e30f71 23 #define HP_FILTER_CUTOFF 0x0F
mja054 0:d62b58e30f71 24 #define PULSE_CFG 0x21
mja054 0:d62b58e30f71 25 #define PULSE_SRC 0x22
mja054 0:d62b58e30f71 26 #define PULSE_THSX 0x23
mja054 0:d62b58e30f71 27 #define PULSE_THSY 0x24
mja054 0:d62b58e30f71 28 #define PULSE_THSZ 0x25
mja054 0:d62b58e30f71 29 #define PULSE_TMLT 0x26
mja054 0:d62b58e30f71 30 #define PULSE_LTCY 0x27
mja054 0:d62b58e30f71 31 #define PULSE_WIND 0x28
mja054 0:d62b58e30f71 32 #define REG_CTRL_REG_1 0x2A
mja054 0:d62b58e30f71 33 #define CTRL_REG2 0x2B
mja054 0:d62b58e30f71 34 #define CTRL_REG4 0x2D
mja054 0:d62b58e30f71 35 #define CTRL_REG5 0x2E
mja054 0:d62b58e30f71 36 #define REG_OUT_X_MSB 0x01
mja054 0:d62b58e30f71 37 #define REG_OUT_Y_MSB 0x03
mja054 0:d62b58e30f71 38 #define REG_OUT_Z_MSB 0x05
mja054 0:d62b58e30f71 39
mja054 0:d62b58e30f71 40 #define UINT14_MAX 16383
mja054 0:d62b58e30f71 41
mja054 0:d62b58e30f71 42 MMA8451Q::MMA8451Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
mja054 0:d62b58e30f71 43 // activate the peripheral
mja054 0:d62b58e30f71 44 uint8_t data[2] = {REG_CTRL_REG_1, 0x01};
mja054 0:d62b58e30f71 45 writeRegs(data, 2);
mja054 0:d62b58e30f71 46 }
mja054 0:d62b58e30f71 47
mja054 0:d62b58e30f71 48 MMA8451Q::~MMA8451Q() { }
mja054 0:d62b58e30f71 49
mja054 0:d62b58e30f71 50 uint8_t MMA8451Q::getWhoAmI() {
mja054 0:d62b58e30f71 51 uint8_t who_am_i = 0;
mja054 0:d62b58e30f71 52 readRegs(REG_WHO_AM_I, &who_am_i, 1);
mja054 0:d62b58e30f71 53 return who_am_i;
mja054 0:d62b58e30f71 54 }
mja054 0:d62b58e30f71 55
mja054 0:d62b58e30f71 56 float MMA8451Q::getAccX() {
mja054 0:d62b58e30f71 57 //divide by 4096 b/c MMA output is 4096 counts per g so this f outputs accelorometer value formatted to g (gravity)
mja054 0:d62b58e30f71 58 return (float(getAccAxis(REG_OUT_X_MSB))/4096.0);
mja054 0:d62b58e30f71 59 }
mja054 0:d62b58e30f71 60
mja054 0:d62b58e30f71 61 float MMA8451Q::getAccY() {
mja054 0:d62b58e30f71 62 return (float(getAccAxis(REG_OUT_Y_MSB))/4096.0);
mja054 0:d62b58e30f71 63 }
mja054 0:d62b58e30f71 64
mja054 0:d62b58e30f71 65 float MMA8451Q::getAccZ() {
mja054 0:d62b58e30f71 66 return (float(getAccAxis(REG_OUT_Z_MSB))/4096.0);
mja054 0:d62b58e30f71 67 }
mja054 0:d62b58e30f71 68
mja054 0:d62b58e30f71 69 void MMA8451Q::getAccAllAxis(float * res) {
mja054 0:d62b58e30f71 70 res[0] = getAccX();
mja054 0:d62b58e30f71 71 res[1] = getAccY();
mja054 0:d62b58e30f71 72 res[2] = getAccZ();
mja054 0:d62b58e30f71 73 }
mja054 0:d62b58e30f71 74
mja054 0:d62b58e30f71 75 int16_t MMA8451Q::getAccAxis(uint8_t addr) {
mja054 0:d62b58e30f71 76 int16_t acc;
mja054 0:d62b58e30f71 77 uint8_t res[2];
mja054 0:d62b58e30f71 78 readRegs(addr, res, 2);
mja054 0:d62b58e30f71 79
mja054 0:d62b58e30f71 80 acc = (res[0] << 6) | (res[1] >> 2);
mja054 0:d62b58e30f71 81 if (acc > UINT14_MAX/2)
mja054 0:d62b58e30f71 82 acc -= UINT14_MAX;
mja054 0:d62b58e30f71 83
mja054 0:d62b58e30f71 84 return acc;
mja054 0:d62b58e30f71 85 }
mja054 0:d62b58e30f71 86
mja054 0:d62b58e30f71 87 void MMA8451Q::setDoubleTap(void){
mja054 0:d62b58e30f71 88 //Implemented directly from Freescale's AN4072
mja054 0:d62b58e30f71 89 //Added to MMA8451Q lib
mja054 0:d62b58e30f71 90
mja054 0:d62b58e30f71 91 uint8_t CTRL_REG1_Data;
mja054 0:d62b58e30f71 92 // int adds;
mja054 0:d62b58e30f71 93 uint8_t data[2] = {REG_CTRL_REG_1, 0x08};
mja054 0:d62b58e30f71 94
mja054 0:d62b58e30f71 95 //400 Hz, Standby Mode
mja054 0:d62b58e30f71 96 writeRegs(data,2);
mja054 0:d62b58e30f71 97
mja054 0:d62b58e30f71 98 //Enable X, Y and Z Double Pulse with DPA = 0 no double pulse abort
mja054 0:d62b58e30f71 99 data[0]=PULSE_CFG;data[1]=0x2A;
mja054 0:d62b58e30f71 100 writeRegs(data,2);
mja054 0:d62b58e30f71 101
mja054 0:d62b58e30f71 102 //SetThreshold 3g on X and Y and 5g on Z
mja054 0:d62b58e30f71 103 //Note: Every step is 0.063g
mja054 0:d62b58e30f71 104 //3 g/0.063g = 48 counts
mja054 0:d62b58e30f71 105 //5g/0.063g = 79 counts
mja054 0:d62b58e30f71 106 data[0]=PULSE_THSX;data[1]=0x30;
mja054 0:d62b58e30f71 107 writeRegs(data,2);//Set X Threshold to 3g
mja054 0:d62b58e30f71 108 data[0]=PULSE_THSY;data[1]=0x30;
mja054 0:d62b58e30f71 109 writeRegs(data,2);//Set Y Threshold to 3g
mja054 0:d62b58e30f71 110 data[0]=PULSE_THSZ;data[1]=0x4F;
mja054 0:d62b58e30f71 111 writeRegs(data,2);//Set Z Threshold to 5g
mja054 0:d62b58e30f71 112
mja054 0:d62b58e30f71 113 //Set Time Limit for Tap Detection to 60 ms LP Mode
mja054 0:d62b58e30f71 114 //Note: 400 Hz ODR, Time step is 1.25 ms per step
mja054 0:d62b58e30f71 115 //60 ms/1.25 ms = 48 counts
mja054 0:d62b58e30f71 116 data[0]=PULSE_TMLT;data[1]=0x30;
mja054 0:d62b58e30f71 117 writeRegs(data,2);//60 ms
mja054 0:d62b58e30f71 118
mja054 0:d62b58e30f71 119 //Set Latency Time to 200 ms
mja054 0:d62b58e30f71 120 //Note: 400 Hz ODR LPMode, Time step is 2.5 ms per step 00 ms/2.5 ms = 80 counts
mja054 0:d62b58e30f71 121 data[0]=PULSE_LTCY;data[1]=0x50;
mja054 0:d62b58e30f71 122 writeRegs(data,2);//200 ms
mja054 0:d62b58e30f71 123
mja054 0:d62b58e30f71 124 //Set Time Window for second tap to 300 ms
mja054 0:d62b58e30f71 125 //Note: 400 Hz ODR LP Mode, Time step is 2.5 ms per step
mja054 0:d62b58e30f71 126 //300 ms/2.5 ms = 120 counts
mja054 0:d62b58e30f71 127 data[0]=PULSE_WIND;data[1]=0x78;
mja054 0:d62b58e30f71 128 writeRegs(data,2);//300 ms
mja054 0:d62b58e30f71 129
mja054 0:d62b58e30f71 130 //Route INT1 to System Interrupt
mja054 0:d62b58e30f71 131 data[0]=CTRL_REG4;data[1]=0x08;
mja054 0:d62b58e30f71 132 writeRegs(data,2);//Enable Pulse Interrupt in System CTRL_REG4
mja054 0:d62b58e30f71 133 data[0]=CTRL_REG5;data[1]=0x08;
mja054 0:d62b58e30f71 134 writeRegs(data,2);//Route Pulse Interrupt to INT1 hardware Pin CTRL_REG5
mja054 0:d62b58e30f71 135
mja054 0:d62b58e30f71 136 //Set the device to Active Mode
mja054 0:d62b58e30f71 137 readRegs(0x2A,&CTRL_REG1_Data,1);//Read out the contents of the register
mja054 0:d62b58e30f71 138 CTRL_REG1_Data |= 0x01; //Change the value in the register to Active Mode.
mja054 0:d62b58e30f71 139 data[0]=REG_CTRL_REG_1;
mja054 0:d62b58e30f71 140 data[1]=CTRL_REG1_Data;
mja054 0:d62b58e30f71 141 writeRegs(data,2);//Write in the updated value to put the device in Active Mode
mja054 0:d62b58e30f71 142 }
mja054 0:d62b58e30f71 143
mja054 0:d62b58e30f71 144
mja054 0:d62b58e30f71 145 void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
mja054 0:d62b58e30f71 146 char t[1] = {addr};
mja054 0:d62b58e30f71 147 m_i2c.write(m_addr, t, 1, true);
mja054 0:d62b58e30f71 148 m_i2c.read(m_addr, (char *)data, len);
mja054 0:d62b58e30f71 149 }
mja054 0:d62b58e30f71 150
mja054 0:d62b58e30f71 151
mja054 0:d62b58e30f71 152
mja054 0:d62b58e30f71 153 void MMA8451Q::writeRegs(uint8_t * data, int len) {
mja054 0:d62b58e30f71 154 m_i2c.write(m_addr, (char *)data, len);
mja054 0:d62b58e30f71 155 }