MMA8452Q I2C library Note: The I2C address is expected to be 7bit address unlike other I2C lib in mbed.
Dependents: test_MMA8452Q HelloWorld testSensor
Diff: MMA8452Q.cpp
- Revision:
- 0:c315c3fd48fb
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MMA8452Q.cpp Sun Dec 13 08:05:49 2015 +0000 @@ -0,0 +1,121 @@ +/* Copyright (c) 2013-2015 Design Methodology Lab + * This driver was delived from MMA8451Q driver at mbed +*/ +/* +* 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. +*/ + +#include "MMA8452Q.h" + +#define REG_CTRL_REG_1 0x2A +#define REG_OUT_X_MSB 0x01 +#define REG_OUT_X_LSB 0x02 +#define REG_OUT_Y_MSB 0x03 +#define REG_OUT_Y_LSB 0x04 +#define REG_OUT_Z_MSB 0x05 +#define REG_OUT_Z_LSB 0x06 +#define REG_SYSMOD 0x0B +#define REG_WHO_AM_I 0x0D +#define REG_ZYZ_DATA_CFG 0x0E +#define REG_HP_FILTER_CUTOFF 0x0F +#define REG_PL_STATUS 0x10 +#define REG_PL_CFG 0x11 +#define REG_PL_COUNT 0x12 +#define REG_PL_BF_ZCOMP 0x13 +#define REG_P_L_THS_REG 0x14 +#define REG_FF_MT_CFG 0x15 +#define REG_FF_MT_SRC 0x16 +#define REG_FF_MT_THS 0x17 +#define REG_FF_MT_COUNT 0x18 +#define REG_TRANSIENT_CFG 0x1D +#define REG_TRANSIENT_SRC 0x1E +#define REG_TRANSIENT_THS 0x1F +#define REG_TRANSIENT_COUNT 0x20 +#define REG_PULSE_CFG 0x21 +#define REG_PULSE_SRC 0x22 +#define REG_PULSE_THSX 0x23 +#define REG_PULSE_THSY 0x24 +#define REG_PULSE_THSZ 0x25 +#define REG_PULSE_TMLT 0x26 +#define REG_PULSE_LTCY 0x27 +#define REG_PULSE_WIND 0x28 +#define REG_ASLP_COUNT 0x29 +#define REG_CTRL_REG1 0x2A +#define REG_CTRL_REG2 0x2B +#define REG_CTRL_REG3 0x2C +#define REG_CTRL_REG4 0x2D +#define REG_CTRL_REG5 0x2E +#define REG_OFF_X 0x2F +#define REG_OFF_Y 0x30 +#define REG_OFF_Z 0x31 + +#define UINT14_MAX 16383 + +MMA8452Q::MMA8452Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr<<1) { + // activate the peripheral + uint8_t data[2] = {REG_CTRL_REG_1, 0x01}; + writeRegs(data, 2); +} + +MMA8452Q::~MMA8452Q() { } + +uint8_t MMA8452Q::getWhoAmI() { + uint8_t who_am_i = 0; + readRegs(REG_WHO_AM_I, &who_am_i, 1); + return who_am_i; +} + +float MMA8452Q::getAccX() { + return (float(getAccAxis(REG_OUT_X_MSB))/4096.0); +} + +float MMA8452Q::getAccY() { + return (float(getAccAxis(REG_OUT_Y_MSB))/4096.0); +} + +float MMA8452Q::getAccZ() { + return (float(getAccAxis(REG_OUT_Z_MSB))/4096.0); +} + +void MMA8452Q::getAccAllAxis(float * res) { + res[0] = getAccX(); + res[1] = getAccY(); + res[2] = getAccZ(); +} + +int16_t MMA8452Q::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 MMA8452Q::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 MMA8452Q::writeRegs(uint8_t * data, int len) { + m_i2c.write(m_addr, (char *)data, len); +}