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(int addr, uint8_t *data, uint32_t len) const
00057 {
00058     char t[1] = {(char)addr};
00059     _i2c->write(_addr, 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 int16_t FXOS8700Q::getSensorAxis(uint8_t addr) const
00076 {
00077     uint8_t res[2];
00078     readRegs(addr, res, sizeof(res));
00079     return static_cast<int16_t>((res[0] << 8) | res[1]);
00080 }
00081 
00082 void FXOS8700Q::enable(void) const
00083 {
00084     uint8_t data[2];
00085     readRegs(FXOS8700Q_CTRL_REG1, &data[1], 1);
00086     data[1] |= 0x01;
00087     data[0] = FXOS8700Q_CTRL_REG1;
00088     writeRegs(data, sizeof(data));
00089 }
00090 
00091 void FXOS8700Q::disable(void) const
00092 {
00093     uint8_t data[2];
00094     readRegs(FXOS8700Q_CTRL_REG1, &data[1], 1);
00095     data[1] &= 0xFE;
00096     data[0] = FXOS8700Q_CTRL_REG1;
00097     writeRegs(data, sizeof(data));
00098 }
00099 
00100 uint32_t FXOS8700Q::dataReady(void) const
00101 {
00102     uint8_t stat = 0;
00103     readRegs(FXOS8700Q_STATUS, &stat, 1);
00104     return (uint32_t)stat;
00105 }
00106 
00107 uint32_t FXOS8700Q::sampleRate(uint32_t frequency) const
00108 {
00109     return(50); // for now sample rate is fixed at 50Hz
00110 }
00111 
00112 int16_t FXOS8700QAccelerometer::getX(int16_t &x = dummy_int16_t) const
00113 {
00114     x = getSensorAxis(FXOS8700Q_OUT_X_MSB) >> 2;
00115     normalize_14bits(x);
00116     return x;
00117 }
00118 
00119 int16_t FXOS8700QAccelerometer::getY(int16_t &y = dummy_int16_t) const
00120 {
00121     y = getSensorAxis(FXOS8700Q_OUT_Y_MSB) >> 2;
00122     normalize_14bits(y);
00123     return y;
00124 }
00125 
00126 int16_t FXOS8700QAccelerometer::getZ(int16_t &z = dummy_int16_t) const
00127 {
00128     z = getSensorAxis(FXOS8700Q_OUT_Z_MSB) >> 2;
00129     normalize_14bits(z);
00130     return z;
00131 }
00132 
00133 float FXOS8700QAccelerometer::getX(float &x = dummy_float) const
00134 {
00135     int16_t val = getSensorAxis(FXOS8700Q_OUT_X_MSB) >> 2;
00136     normalize_14bits(val);
00137     x = val / 4096.0f;
00138     return x;
00139 }
00140 
00141 float FXOS8700QAccelerometer::getY(float &y = dummy_float) const
00142 {
00143     int16_t val = getSensorAxis(FXOS8700Q_OUT_Y_MSB) >> 2;
00144     normalize_14bits(val);
00145     y = val / 4096.0f;
00146     return y;
00147 }
00148 
00149 float FXOS8700QAccelerometer::getZ(float &z = dummy_float) const
00150 {
00151     int16_t val = getSensorAxis(FXOS8700Q_OUT_Z_MSB) >> 2;
00152     normalize_14bits(val);
00153     z = val / 4096.0f;
00154     return z;
00155 }
00156 
00157 void FXOS8700QAccelerometer::getAxis(motion_data_counts_t &xyz) const
00158 {
00159     uint8_t res[6];
00160     readRegs(FXOS8700Q_OUT_X_MSB, res, sizeof(res));
00161     xyz.x = static_cast<int16_t>((res[0] << 8) | res[1]) >> 2;
00162     xyz.y = static_cast<int16_t>((res[2] << 8) | res[3]) >> 2;
00163     xyz.z = static_cast<int16_t>((res[4] << 8) | res[5]) >> 2;
00164     normalize_14bits(xyz.x);
00165     normalize_14bits(xyz.y);
00166     normalize_14bits(xyz.z);
00167 }
00168 
00169 void FXOS8700QAccelerometer::getAxis(motion_data_units_t &xyz) const
00170 {
00171     motion_data_counts_t _xyz;
00172     FXOS8700QAccelerometer::getAxis(_xyz);
00173     xyz.x = _xyz.x / 4096.0f;
00174     xyz.y = _xyz.y / 4096.0f;
00175     xyz.z = _xyz.z / 4096.0f;
00176 }
00177 
00178 int16_t FXOS8700QMagnetometer::getX(int16_t &x = dummy_int16_t) const
00179 {
00180     x = getSensorAxis(FXOS8700Q_M_OUT_X_MSB);
00181     return x;
00182 }
00183 
00184 int16_t FXOS8700QMagnetometer::getY(int16_t &y = dummy_int16_t) const
00185 {
00186     y = getSensorAxis(FXOS8700Q_M_OUT_Y_MSB);
00187     return y;
00188 }
00189 
00190 int16_t FXOS8700QMagnetometer::getZ(int16_t &z = dummy_int16_t) const
00191 {
00192     z = getSensorAxis(FXOS8700Q_M_OUT_Z_MSB);
00193     return z;
00194 }
00195 
00196 float FXOS8700QMagnetometer::getX(float &x = dummy_float) const
00197 {
00198     x = static_cast<float>(getSensorAxis(FXOS8700Q_M_OUT_X_MSB)) * 0.1f;
00199     return x;
00200 }
00201 
00202 float FXOS8700QMagnetometer::getY(float &y = dummy_float) const
00203 {
00204     y = static_cast<float>(getSensorAxis(FXOS8700Q_M_OUT_Y_MSB)) * 0.1f;
00205     return y;
00206 }
00207 
00208 float FXOS8700QMagnetometer::getZ(float &z = dummy_float) const
00209 {
00210     z = static_cast<float>(getSensorAxis(FXOS8700Q_M_OUT_Z_MSB)) * 0.1f;
00211     return z;
00212 }
00213 
00214 void FXOS8700QMagnetometer::getAxis(motion_data_counts_t &xyz) const
00215 {
00216     uint8_t res[6];
00217     readRegs(FXOS8700Q_M_OUT_X_MSB, res, sizeof(res));
00218     xyz.x = (res[0] << 8) | res[1];
00219     xyz.y = (res[2] << 8) | res[3];
00220     xyz.z = (res[4] << 8) | res[5];
00221 }
00222 
00223 void FXOS8700QMagnetometer::getAxis(motion_data_units_t &xyz) const
00224 {
00225     motion_data_counts_t _xyz;
00226     FXOS8700QMagnetometer::getAxis(_xyz);
00227     xyz.x = static_cast<float>(_xyz.x * 0.1f);
00228     xyz.y = static_cast<float>(_xyz.y * 0.1f);
00229     xyz.z = static_cast<float>(_xyz.z * 0.1f);
00230 }