SB-HW-8.1
Fork of MMA8451Q8 by
Diff: MMA8451Q8b.cpp
- Revision:
- 8:31f7a3426768
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MMA8451Q8b.cpp Wed Mar 08 04:11:07 2017 +0000 @@ -0,0 +1,125 @@ +/* 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 "MMA8451Q8b.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 + +#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}; //scalin 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::setStandbyMode() { +#define ACTIVEMASK 0x01 + uint8_t registerData[1]; + uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00}; + + readRegs(REG_CTRL_REG_1, registerData, 1); + data[1] = registerData[0] & ~ACTIVEMASK; + writeRegs(data, NUM_DATA); //put in standby +} + +void MMA8451Q::setActiveMode(){ +#define ACTIVEMASK 0x01 + uint8_t registerData[1]; + uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00}; + + readRegs(REG_CTRL_REG_1, registerData, 1); + data[1] = registerData[0] | ACTIVEMASK; + writeRegs(data, NUM_DATA); //put in standby +} + +void MMA8451Q::setGLimit(int gSelect) { + uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00}; + gChosen = gSelect; + setStandbyMode(); + data[ADDRESS_INDEX] = XYZ_DATA_CFG; + data[DATA_INDEX] = gChosen; + writeRegs(data, 2);// change g limit + setActiveMode(); +} + +float MMA8451Q::getAccX() { + return (float(getAccAxis(REG_OUT_X_MSB))/GSCALING); +} + +float MMA8451Q::getAccY() { + return (float(getAccAxis(REG_OUT_Y_MSB))/GSCALING); +} + +float MMA8451Q::getAccZ() { + return (float(getAccAxis(REG_OUT_Z_MSB))/GSCALING); +} + +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); +}