hw 4.2.2
Fork of MMA8451Q8b by
MMA8451Q8.cpp
- Committer:
- scohennm
- Date:
- 2015-02-03
- Revision:
- 8:993bb9e96a4b
- Parent:
- 7:ed7e11d269f8
- Child:
- 9:4e96b8139119
File content as of revision 8:993bb9e96a4b:
/* Copyright (c) 2010-2011 mbed.org, MIT License * * Permission is hereby granted, free of charge, to any person obtaining a copy of this software * and associated documentation files (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all copies or * substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ // Modify to change full scale gravity range 141207 sc #include "MMA8451Q8.h" #define REG_WHO_AM_I 0x0D #define REG_CTRL_REG_1 0x2A #define REG_OUT_X_MSB 0x01 #define REG_OUT_Y_MSB 0x03 #define REG_OUT_Z_MSB 0x05 #define XYZ_DATA_CFG 0x0E // adding tap config register adderesses #define REG_PULSE_SRC 0x22 #define REG_PULSE_CFG 0x21 #define UINT14_MAX 16383 #define MAX_2G 0x00 #define MAX_4G 0x01 #define MAX_8G 0x02 #define NUM_DATA 2 #define GSCALING 1024.0 #define ADDRESS_INDEX 0 #define DATA_INDEX 1 float gScaling[3] = {4095.0,2048.0,1024.0}; //scaling for acceleration of gravity values MMA8451Q::MMA8451Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) { // activate the peripheral uint8_t data[2] = {REG_CTRL_REG_1, 0x01}; writeRegs(data, 2); } MMA8451Q::~MMA8451Q() { } uint8_t MMA8451Q::getWhoAmI() { uint8_t who_am_i = 0; readRegs(REG_WHO_AM_I, &who_am_i, 1); return who_am_i; } void MMA8451Q::setGLimit(int gSelect) { uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00}; gChosen = gSelect; writeRegs(data, NUM_DATA); // put in standby data[ADDRESS_INDEX ] = XYZ_DATA_CFG; data[DATA_INDEX] = gChosen; writeRegs(data, 2);// change g limit data[ADDRESS_INDEX ] = REG_CTRL_REG_1; data[DATA_INDEX] = 0x01; writeRegs(data, 2); // make active } // add Puse configuratioin register access // Also add function prototype to .h file void MMA8451Q::setPulseConfiguration(uint8_t latch,uint8_t axisSet) { uint8_t configBits; uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00}; // put in standby mode // set up configuration bits. configBits = latch | axisSet; writeRegs(data, NUM_DATA); // put in standby data[ADDRESS_INDEX ] = REG_PULSE_CFG; data[DATA_INDEX] = configBits; writeRegs(data, NUM_DATA); data[ADDRESS_INDEX ] = REG_CTRL_REG_1; // put back in active mode data[DATA_INDEX] = 0x01; writeRegs(data, 2); // make active } float MMA8451Q::getAccX() { return (float(getAccAxis(REG_OUT_X_MSB))/gScaling[gChosen]); } float MMA8451Q::getAccY() { return (float(getAccAxis(REG_OUT_Y_MSB))/gScaling[gChosen]); } float MMA8451Q::getAccZ() { return (float(getAccAxis(REG_OUT_Z_MSB))/gScaling[gChosen]); } void MMA8451Q::getAccAllAxis(float * res) { res[0] = getAccX(); res[1] = getAccY(); res[2] = getAccZ(); } int16_t MMA8451Q::getAccAxis(uint8_t addr) { int16_t acc; uint8_t res[2]; readRegs(addr, res, 2); acc = (res[0] << 6) | (res[1] >> 2); if (acc > UINT14_MAX/2) acc -= UINT14_MAX; return acc; } void MMA8451Q::readRegs(int addr, uint8_t * data, int len) { char t[1] = {addr}; m_i2c.write(m_addr, t, 1, true); m_i2c.read(m_addr, (char *)data, len); } void MMA8451Q::writeRegs(uint8_t * data, int len) { m_i2c.write(m_addr, (char *)data, len); }