1 #include "accelerometer.h"
9 #define kFilteringFactor 0.1
11 #define kFileName "/sys/class/i2c-adapter/i2c-3/3-001d/coord"
13 static int sampleIndex=0;
16 * Default constructor for Accelerometer class
19 Accelerometer::Accelerometer()
21 calculate = new Calculate();
23 timer = new QTimer(this);
24 connect(timer, SIGNAL(timeout()), this, SLOT(processData()));
30 * Constructor for Accelerometer class that takes accelerometer sample rate as parameter
32 * @param p_SampleRate the desired sample rate of accelerometer in milliseconds
34 Accelerometer::Accelerometer(int p_SampleRate)
36 calculate = new Calculate();
38 timer = new QTimer(this);
39 connect(timer, SIGNAL(timeout()), this, SLOT(processData()));
40 sampleRate = p_SampleRate;
45 * Default destructor for Accelerometer class
48 Accelerometer::~Accelerometer()
56 void Accelerometer::start()
60 timer->start(sampleRate);
68 void Accelerometer::initValues()
76 previousAccelerationX=0;
77 previousAccelerationY=0;
78 previousAccelerationZ=0;
81 currentAcceleration=0;
82 previousAcceleration=0;
87 lastDistanceTraveled=0;
90 reverseAcceleration = false;
94 * Calibrate. Purpose of this function is to calibrate
95 * accelerometer when stationary.
98 void Accelerometer::calibrate(void)
100 unsigned int iteration = 0;
103 // Opening the file must be done inside the loop
104 // or else the values obtained from file.readLine();
105 // will be empty for all but the first iteration
106 QFile file(kFileName);
107 if(!file.open(QIODevice::ReadOnly | QIODevice::Text))
113 QRegExp rx("([0-9-]+) ([0-9-]+) ([0-9-]+)");
115 // Read data, parse with regular expressions and process it
116 line = file.readLine();
119 int sampleX = rx.cap(1).toInt();
120 int sampleY = rx.cap(2).toInt();
121 int sampleZ = rx.cap(3).toInt();
123 calibrationX = calibrationX + sampleX; // Accumulate Samples
124 calibrationY = calibrationY + sampleY; // for all axes.
125 calibrationZ = calibrationZ + sampleZ;
130 } while(iteration != 1024); // 1024 times
132 calibrationX = calibrationX>>10; // division by 1024
133 calibrationY = calibrationY>>10;
134 calibrationZ = calibrationZ>>10;
141 void Accelerometer::stop()
147 * Set the sample rate of accelerometer
149 * @param pSampleRate desired sample rate
151 void Accelerometer::setSampleRate(int pSampleRate)
153 sampleRate = pSampleRate;
157 * Get the sample rate of accelerometer
159 * @return sampleRate the sample rate of the accelerometer in milliseconds
161 int Accelerometer::getSampleRate()
166 qreal Accelerometer::getCurrentAcceleration()
168 return currentAcceleration;
171 qreal Accelerometer::getPreviousTotalAcceleration()
173 return previousAcceleration;
176 qreal Accelerometer::getTotalAcceleration()
178 return totalAcceleration;
181 qreal Accelerometer::getDistanceTraveled()
183 return distanceTraveled;
186 qreal Accelerometer::getLastDistanceTraveled()
188 return lastDistanceTraveled;
191 qreal Accelerometer::getAverageSpeed()
196 qreal Accelerometer::getTrueAccelerationX()
198 return trueAccelerationX;
201 qreal Accelerometer::getTrueAccelerationY()
203 return trueAccelerationY;
206 qreal Accelerometer::getTrueAccelerationZ()
208 return trueAccelerationZ;
211 qreal Accelerometer::getPreviousSpeed()
213 return previousSpeed;
216 qreal Accelerometer::getCurrentSpeed()
221 qreal Accelerometer::getIntervalTime()
226 qreal Accelerometer::getTotalTime()
232 * Processes Accelerometer data
234 * Opens the accelerometer value file for reading and reads and parses accelerometer values.
235 * Forwards data to Calculate class for processing
238 void Accelerometer::processData()
240 QFile file(kFileName);
241 if(!file.open(QIODevice::ReadOnly | QIODevice::Text)) return;
243 // Read data, parse with regular expressions and process it
244 QByteArray line = file.readLine();
245 QRegExp rx("([0-9-]+) ([0-9-]+) ([0-9-]+)");
248 smoothData(rx.cap(1).toInt(), rx.cap(2).toInt(), rx.cap(3).toInt());
251 trueAccelerationX = accelerationX - calibrationX;
252 trueAccelerationY = accelerationY - calibrationY;
253 trueAccelerationZ = accelerationZ - calibrationZ;
255 // Discrimination window for acceleration values
256 if (trueAccelerationX <= 30 && trueAccelerationX >= -30) { trueAccelerationX = 0; }
257 if (trueAccelerationY <= 30 && trueAccelerationY >= -30) { trueAccelerationY = 0; }
258 if (trueAccelerationZ <= 30 && trueAccelerationZ >= -30) { trueAccelerationZ = 0; }
260 trueAccelerationX = (accelerationX - previousAccelerationX) /*/ 1000 * kGravity*/;
261 trueAccelerationY = (accelerationY - previousAccelerationY) /*/ 1000 * kGravity*/;
262 trueAccelerationZ = (accelerationZ - previousAccelerationZ) /*/ 1000 * kGravity*/;
264 previousAccelerationX = accelerationX;
265 previousAccelerationY = accelerationY;
266 previousAccelerationZ = accelerationZ;
268 currentAcceleration = sqrt(trueAccelerationX * trueAccelerationX +
269 trueAccelerationY * trueAccelerationY +
270 trueAccelerationZ * trueAccelerationZ );
272 totalAcceleration = currentAcceleration - previousAcceleration;
273 previousAcceleration = currentAcceleration;
275 // Measure time interval
276 intervalTime = now.restart(); // millisecs to secs
277 intervalTime = intervalTime/1000;
278 totalTime = totalTime + intervalTime;
280 // Filter out acceleration caused by noise.
281 if (fabs(currentAcceleration) < 0.09) {
285 // Using calculate class to calculate velocity and distance etc.
286 calculate->calculateParameters(currentAcceleration,intervalTime );
288 currentSpeed = calculate->getCurrentSpeed();
289 distanceTraveled = calculate->getDistanceTraveled();
295 * Smooths Accelerometer data
297 * @param x accelerometer's x-axis input
298 * @param y accelerometer's y-axis input
299 * @param z accelerometer's z-axis input
301 void Accelerometer::smoothData(qreal x, qreal y, qreal z)
307 accelerationX = previousAccelerationX + (accelerationX-previousAccelerationX) * kFilteringFactor;
308 accelerationY = previousAccelerationY + (accelerationY-previousAccelerationY) * kFilteringFactor;
309 accelerationZ = previousAccelerationZ + (accelerationZ-previousAccelerationZ) * kFilteringFactor;