My version of the library for this accelerometer. It works on 800Hz data rate.
Fork of MMA8451Q by
Diff: MMA8451Q.cpp
- Revision:
- 0:7c9ab58f6af3
- Child:
- 1:9c229882cd2b
diff -r 000000000000 -r 7c9ab58f6af3 MMA8451Q.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MMA8451Q.cpp Wed Jun 04 19:16:47 2014 +0000 @@ -0,0 +1,75 @@ +/* Copyright (c) 2010-2011 mbed.org, MIT License +* Copyright (c) 2014 Antonio Quevedo, UNICAMP +* +* 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 "MMA8451Q.h" + +#define ACCEL_I2C_ADDRESS 0x1D<<1 +#define REG_STATUS 0x00 +#define REG_XYZ_DATA_CFG 0x0E +#define REG_WHO_AM_I 0x0D +#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_OUT_X_MSB 0x01 +#define REG_OUT_Y_MSB 0x03 +#define REG_OUT_Z_MSB 0x05 + +MMA8451Q::MMA8451Q(PinName sda, PinName scl) : m_i2c(sda, scl) { + uint8_t data[2] = {REG_CTRL_REG1, 0x00}; // Puts acc in standby for configuring + writeRegs(data, 2); + data[0] = REG_XYZ_DATA_CFG; // Writing 00 turns off high-pass filter and sets full scale range to 2g + // data[1] = 0x01; for 4g + // data[1] = 0x02; for 8g + writeRegs(data, 2); + data[0] = REG_CTRL_REG2; + data[1] = 0x00; // Disable self-test, software reset and auto-sleep; operates in normal mode + writeRegs(data, 2); + data[0] = REG_CTRL_REG3; // Interrupt polarity low, push-pull output + writeRegs(data, 2); + data[0] = REG_CTRL_REG4; + data[1] = 0x01; // Enables interrupt for data Ready + writeRegs(data, 2); + data[0] = REG_CTRL_REG5; + writeRegs(data, 2); // Routes Data Ready interrupt to INT1 + data[0] = REG_CTRL_REG1; + data[1] = 0x09; // Data rate is 800Hz + writeRegs(data, 2); +} + +MMA8451Q::~MMA8451Q() { } + +void MMA8451Q::getAccAllAxis(int16_t * res) { + uint8_t temp[6]; + readRegs(REG_OUT_X_MSB, temp, 6); + res[0] = (temp[0] * 256) + temp[1]; + res[1] = (temp[2] * 256) + temp[3]; + res[2] = (temp[4] * 256) + temp[5]; +} + +void MMA8451Q::readRegs(int addr, uint8_t * data, int len) { + char t[1] = {addr}; + m_i2c.write(ACCEL_I2C_ADDRESS, t, 1, true); + m_i2c.read(ACCEL_I2C_ADDRESS, (char *)data, len); +} + +void MMA8451Q::writeRegs(uint8_t * data, int len) { + m_i2c.write(ACCEL_I2C_ADDRESS, (char *)data, len); +} \ No newline at end of file