FXOS8700Q.cpp

00001 /* FXOS8700Q sensor driver
00002  * Copyright (c) 2014-2015 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #include "FXOS8700Q.h"
00018 
00019 const uint16_t uint14_max = 0x3FFF;
00020 void static inline normalize_14bits(int16_t &x)
00021 {
00022     x = ((x) > (uint14_max/2)) ? (x - uint14_max) : (x);
00023 }
00024 
00025 static int16_t dummy_int16_t = 0;
00026 static float dummy_float = 0.0f;
00027 
00028 FXOS8700Q::FXOS8700Q(I2C &i2c, uint8_t addr)
00029 {
00030     _i2c = &i2c;
00031     _addr = addr;
00032     // activate the peripheral
00033     uint8_t data[2] = {FXOS8700Q_CTRL_REG1, 0x00};
00034     _i2c->frequency(400000);
00035     writeRegs(data, 2);
00036     data[0] = FXOS8700Q_M_CTRL_REG1;
00037     data[1] = 0x1F;
00038     writeRegs(data, 2);
00039     data[0] = FXOS8700Q_M_CTRL_REG2;
00040     data[1] = 0x20;
00041     writeRegs(data, 2);
00042     data[0] = FXOS8700Q_XYZ_DATA_CFG;
00043     data[1] = 0x00;
00044     writeRegs(data, 2);
00045     data[0] = FXOS8700Q_CTRL_REG1;
00046     data[1] = 0x1C;
00047     writeRegs(data, 2);
00048 }
00049 
00050 FXOS8700Q::~FXOS8700Q()
00051 {
00052     _i2c = 0;
00053     _addr = 0;
00054 }
00055 
00056 void FXOS8700Q::readRegs(uint8_t addr, uint8_t *data, uint32_t len) const
00057 {
00058     uint8_t t[1] = {addr};
00059     _i2c->write(_addr, (char *)t, sizeof(t), true);
00060     _i2c->read(_addr, (char *)data, len);
00061 }
00062 
00063 uint8_t FXOS8700Q::whoAmI() const
00064 {
00065     uint8_t who_am_i = 0;
00066     readRegs(FXOS8700Q_WHOAMI, &who_am_i, sizeof(who_am_i));
00067     return who_am_i;
00068 }
00069 
00070 void FXOS8700Q::writeRegs(uint8_t * data, uint32_t len) const
00071 {
00072     _i2c->write(_addr, (char *)data, len);
00073 }
00074 
00075 
00076 int16_t FXOS8700Q::getSensorAxis(uint8_t addr) const
00077 {
00078     uint8_t res[2];
00079     readRegs(addr, res, sizeof(res));
00080     return static_cast<int16_t>((res[0] << 8) | res[1]);
00081 }
00082 
00083 void FXOS8700Q::enable(void) const
00084 {
00085     uint8_t data[2];
00086     readRegs(FXOS8700Q_CTRL_REG1, &data[1], 1);
00087     data[1] |= 0x01;
00088     data[0] = FXOS8700Q_CTRL_REG1;
00089     writeRegs(data, sizeof(data));
00090 }
00091 
00092 void FXOS8700Q::disable(void) const
00093 {
00094     uint8_t data[2];
00095     readRegs(FXOS8700Q_CTRL_REG1, &data[1], 1);
00096     data[1] &= 0xFE;
00097     data[0] = FXOS8700Q_CTRL_REG1;
00098     writeRegs(data, sizeof(data));
00099 }
00100 
00101 uint32_t FXOS8700Q::dataReady(void) const
00102 {
00103     uint8_t stat = 0;
00104     readRegs(FXOS8700Q_STATUS, &stat, 1);
00105     return (uint32_t)stat;
00106 }
00107 
00108 uint32_t FXOS8700Q::sampleRate(uint32_t frequency) const
00109 {
00110     return(50); // for now sample rate is fixed at 50Hz
00111 }
00112 
00113 int16_t FXOS8700QAccelerometer::getX(int16_t &x = dummy_int16_t) const
00114 {
00115     x = getSensorAxis(FXOS8700Q_OUT_X_MSB) >> 2;
00116     normalize_14bits(x);
00117     return x;
00118 }
00119 
00120 int16_t FXOS8700QAccelerometer::getY(int16_t &y = dummy_int16_t) const
00121 {
00122     y = getSensorAxis(FXOS8700Q_OUT_Y_MSB) >> 2;
00123     normalize_14bits(y);
00124     return y;
00125 }
00126 
00127 int16_t FXOS8700QAccelerometer::getZ(int16_t &z = dummy_int16_t) const
00128 {
00129     z = getSensorAxis(FXOS8700Q_OUT_Z_MSB) >> 2;
00130     normalize_14bits(z);
00131     return z;
00132 }
00133 
00134 float FXOS8700QAccelerometer::getX(float &x = dummy_float) const
00135 {
00136     int16_t val = getSensorAxis(FXOS8700Q_OUT_X_MSB) >> 2;
00137     normalize_14bits(val);
00138     x = val / 4096.0f;
00139     return x;
00140 }
00141 
00142 float FXOS8700QAccelerometer::getY(float &y = dummy_float) const
00143 {
00144     int16_t val = getSensorAxis(FXOS8700Q_OUT_Y_MSB) >> 2;
00145     normalize_14bits(val);
00146     y = val / 4096.0f;
00147     return y;
00148 }
00149 
00150 float FXOS8700QAccelerometer::getZ(float &z = dummy_float) const
00151 {
00152     int16_t val = getSensorAxis(FXOS8700Q_OUT_Z_MSB) >> 2;
00153     normalize_14bits(val);
00154     z = val / 4096.0f;
00155     return z;
00156 }
00157 
00158 void FXOS8700QAccelerometer::getAxis(motion_data_counts_t &xyz) const
00159 {
00160     uint8_t res[6];
00161     readRegs(FXOS8700Q_OUT_X_MSB, res, sizeof(res));
00162     xyz.x = static_cast<int16_t>((res[0] << 8) | res[1]) >> 2;
00163     xyz.y = static_cast<int16_t>((res[2] << 8) | res[3]) >> 2;
00164     xyz.z = static_cast<int16_t>((res[4] << 8) | res[5]) >> 2;
00165     normalize_14bits(xyz.x);
00166     normalize_14bits(xyz.y);
00167     normalize_14bits(xyz.z);
00168 }
00169 
00170 void FXOS8700QAccelerometer::getAxis(motion_data_units_t &xyz) const
00171 {
00172     motion_data_counts_t _xyz;
00173     FXOS8700QAccelerometer::getAxis(_xyz);
00174     xyz.x = _xyz.x / 4096.0f;
00175     xyz.y = _xyz.y / 4096.0f;
00176     xyz.z = _xyz.z / 4096.0f;
00177 }
00178 
00179 int16_t FXOS8700QMagnetometer::getX(int16_t &x = dummy_int16_t) const
00180 {
00181     x = getSensorAxis(FXOS8700Q_M_OUT_X_MSB);
00182     return x;
00183 }
00184 
00185 int16_t FXOS8700QMagnetometer::getY(int16_t &y = dummy_int16_t) const
00186 {
00187     y = getSensorAxis(FXOS8700Q_M_OUT_Y_MSB);
00188     return y;
00189 }
00190 
00191 int16_t FXOS8700QMagnetometer::getZ(int16_t &z = dummy_int16_t) const
00192 {
00193     z = getSensorAxis(FXOS8700Q_M_OUT_Z_MSB);
00194     return z;
00195 }
00196 
00197 float FXOS8700QMagnetometer::getX(float &x = dummy_float) const
00198 {
00199     x = static_cast<float>(getSensorAxis(FXOS8700Q_M_OUT_X_MSB)) * 0.1f;
00200     return x;
00201 }
00202 
00203 float FXOS8700QMagnetometer::getY(float &y = dummy_float) const
00204 {
00205     y = static_cast<float>(getSensorAxis(FXOS8700Q_M_OUT_Y_MSB)) * 0.1f;
00206     return y;
00207 }
00208 
00209 float FXOS8700QMagnetometer::getZ(float &z = dummy_float) const
00210 {
00211     z = static_cast<float>(getSensorAxis(FXOS8700Q_M_OUT_Z_MSB)) * 0.1f;
00212     return z;
00213 }
00214 
00215 void FXOS8700QMagnetometer::getAxis(motion_data_counts_t &xyz) const
00216 {
00217     uint8_t res[6];
00218     readRegs(FXOS8700Q_M_OUT_X_MSB, res, sizeof(res));
00219     xyz.x = (res[0] << 8) | res[1];
00220     xyz.y = (res[2] << 8) | res[3];
00221     xyz.z = (res[4] << 8) | res[5];
00222 }
00223 
00224 void FXOS8700QMagnetometer::getAxis(motion_data_units_t &xyz) const
00225 {
00226     motion_data_counts_t _xyz;
00227     FXOS8700QMagnetometer::getAxis(_xyz);
00228     xyz.x = static_cast<float>(_xyz.x * 0.1f);
00229     xyz.y = static_cast<float>(_xyz.y * 0.1f);
00230     xyz.z = static_cast<float>(_xyz.z * 0.1f);
00231 }