////  SerialInterface.cpp//  2012 by Philip Rosedale for High Fidelity Inc.////  Read interface data from the gyros/accelerometer Invensense board using the SerialUSB// #ifndef _WIN32#include <regex.h>#include <sys/time.h>#include <string>#endif #include <math.h> #include <glm/gtx/vector_angle.hpp> extern "C" {    #include <inv_tty.h>    #include <inv_mpu.h>} #include <SharedUtil.h> #include "Application.h"#include "SerialInterface.h"#include "Util.h"#include "Webcam.h" const short NO_READ_MAXIMUM_MSECS = 3000;const int GRAVITY_SAMPLES = 60;                     //  Use the first few samples to baseline valuesconst int NORTH_SAMPLES = 30;const int ACCELERATION_SENSOR_FUSION_SAMPLES = 20;const int COMPASS_SENSOR_FUSION_SAMPLES = 100;const int LONG_TERM_RATE_SAMPLES = 1000;             const bool USING_INVENSENSE_MPU9150 = 1; SerialInterface::SerialInterface() :    _active(false),    _gravity(0, 0, 0),    _averageRotationRates(0, 0, 0),    _averageAcceleration(0, 0, 0),    _estimatedRotation(0, 0, 0),    _estimatedPosition(0, 0, 0),    _estimatedVelocity(0, 0, 0),    _lastAcceleration(0, 0, 0),    _lastRotationRates(0, 0, 0),    _compassMinima(-211, -132, -186),    _compassMaxima(89, 95, 98),    _angularVelocityToLinearAccel(0.003f, -0.001f, -0.006f,                                  -0.005f, -0.001f, -0.006f,                                  0.010f, 0.004f, 0.007f),    _angularAccelToLinearAccel(0.0f, 0.0f, 0.002f,                               0.0f, 0.0f, 0.001f,                               -0.002f, -0.002f, 0.0f){ } void SerialInterface::pair() {    #ifndef _WIN32    // look for a matching gyro setup    DIR *devDir;    struct dirent *entry;    int matchStatus;    regex_t regex;        // for now this only works on OS X, where the usb serial shows up as /dev/tty.usb*,    // and (possibly just Ubuntu) Linux, where it shows up as /dev/ttyACM*    if((devDir = opendir("/dev"))) {        while((entry = readdir(devDir))) {#ifdef __APPLE__            regcomp(&regex, "tty\\.usb", REG_EXTENDED|REG_NOSUB);#else            regcomp(&regex, "ttyACM", REG_EXTENDED|REG_NOSUB);#endif            matchStatus = regexec(&regex, entry->d_name, (size_t) 0, NULL, 0);            if (matchStatus == 0) {                char *serialPortname = new char[100];                sprintf(serialPortname, "/dev/%s", entry->d_name);                                initializePort(serialPortname);                                delete [] serialPortname;            }            regfree(&regex);        }        closedir(devDir);    }    #endif} //  connect to the serial portvoid SerialInterface::initializePort(char* portname) {#ifndef _WIN32    _serialDescriptor = open(portname, O_RDWR | O_NOCTTY | O_NDELAY);        qDebug("Opening SerialUSB %s: ", portname);        if (_serialDescriptor == -1) {        qDebug("Failed.\n");        return;    }        struct termios options;    tcgetattr(_serialDescriptor, &options);            options.c_cflag |= (CLOCAL | CREAD | CS8);    options.c_cflag &= ~PARENB;    options.c_cflag &= ~CSTOPB;    options.c_cflag &= ~CSIZE;    tcsetattr(_serialDescriptor, TCSANOW, &options);        cfsetispeed(&options,B115200);    cfsetospeed(&options,B115200);        if (USING_INVENSENSE_MPU9150) {        // block on invensense reads until there is data to read        int currentFlags = fcntl(_serialDescriptor, F_GETFL);        fcntl(_serialDescriptor, F_SETFL, currentFlags & ~O_NONBLOCK);                // make sure there's nothing queued up to be read        tcflush(_serialDescriptor, TCIOFLUSH);                // this disables streaming so there's no garbage data on reads        write(_serialDescriptor, "SD\n", 3);        char result[4];        read(_serialDescriptor, result, 4);                tty_set_file_descriptor(_serialDescriptor);        mpu_init(0);        mpu_set_sensors(INV_XYZ_GYRO | INV_XYZ_ACCEL | INV_XYZ_COMPASS);    }        qDebug("Connected.\n");    resetSerial();        _active = true; #endif} //  Render the serial interface channel values onscreen as vertical linesvoid SerialInterface::renderLevels(int width, int height) {    char val[40];    if (USING_INVENSENSE_MPU9150) {        //  For invensense gyros, render as horizontal bars        const int LEVEL_CORNER_X = 10;        const int LEVEL_CORNER_Y = 200;                // Draw the numeric degree/sec values from the gyros        sprintf(val, "Yaw    %4.1f", _estimatedRotation.y);        drawtext(LEVEL_CORNER_X, LEVEL_CORNER_Y, 0.10, 0, 1.0, 1, val, 0, 1, 0);        sprintf(val, "Pitch %4.1f", _estimatedRotation.x);        drawtext(LEVEL_CORNER_X, LEVEL_CORNER_Y + 15, 0.10, 0, 1.0, 1, val, 0, 1, 0);        sprintf(val, "Roll  %4.1f", _estimatedRotation.z);        drawtext(LEVEL_CORNER_X, LEVEL_CORNER_Y + 30, 0.10, 0, 1.0, 1, val, 0, 1, 0);        sprintf(val, "X     %4.3f", _lastAcceleration.x - _gravity.x);        drawtext(LEVEL_CORNER_X, LEVEL_CORNER_Y + 45, 0.10, 0, 1.0, 1, val, 0, 1, 0);        sprintf(val, "Y     %4.3f", _lastAcceleration.y - _gravity.y);        drawtext(LEVEL_CORNER_X, LEVEL_CORNER_Y + 60, 0.10, 0, 1.0, 1, val, 0, 1, 0);        sprintf(val, "Z     %4.3f", _lastAcceleration.z - _gravity.z);        drawtext(LEVEL_CORNER_X, LEVEL_CORNER_Y + 75, 0.10, 0, 1.0, 1, val, 0, 1, 0);                //  Draw the levels as horizontal lines                const int LEVEL_CENTER = 150;        const float ACCEL_VIEW_SCALING = 10.f;        const float POSITION_SCALING = 400.f;         glLineWidth(2.0);        glBegin(GL_LINES);        // Rotation rates        glColor4f(1, 1, 1, 1);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y - 3);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + getLastYawRate(), LEVEL_CORNER_Y - 3);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y + 12);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + getLastPitchRate(), LEVEL_CORNER_Y + 12);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y + 27);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + getLastRollRate(), LEVEL_CORNER_Y + 27);        // Estimated Rotation        glColor4f(0, 1, 1, 1);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y - 1);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + _estimatedRotation.y, LEVEL_CORNER_Y - 1);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y + 14);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + _estimatedRotation.x, LEVEL_CORNER_Y + 14);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y + 29);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + _estimatedRotation.z, LEVEL_CORNER_Y + 29);         // Acceleration rates        glColor4f(1, 1, 1, 1);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y + 42);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + (int)(_estimatedAcceleration.x * ACCEL_VIEW_SCALING), LEVEL_CORNER_Y + 42);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y + 57);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + (int)(_estimatedAcceleration.y * ACCEL_VIEW_SCALING), LEVEL_CORNER_Y + 57);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y + 72);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + (int)(_estimatedAcceleration.z * ACCEL_VIEW_SCALING), LEVEL_CORNER_Y + 72);                // Estimated Position        glColor4f(0, 1, 1, 1);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y + 44);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + (int)(_estimatedPosition.x * POSITION_SCALING), LEVEL_CORNER_Y + 44);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y + 59);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + (int)(_estimatedPosition.y * POSITION_SCALING), LEVEL_CORNER_Y + 59);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y + 74);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER + (int)(_estimatedPosition.z * POSITION_SCALING), LEVEL_CORNER_Y + 74);          glEnd();        //  Draw green vertical centerline        glColor4f(0, 1, 0, 0.5);        glBegin(GL_LINES);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y - 6);        glVertex2f(LEVEL_CORNER_X + LEVEL_CENTER, LEVEL_CORNER_Y + 30);        glEnd();    }} void SerialInterface::readData(float deltaTime) {#ifndef _WIN32        int initialSamples = totalSamples;        if (USING_INVENSENSE_MPU9150) {          // ask the invensense for raw gyro data        short accelData[3];        if (mpu_get_accel_reg(accelData, 0)) {            close(_serialDescriptor);            qDebug("Disconnected SerialUSB.\n");            _active = false;            return; // disconnected        }                const float LSB_TO_METERS_PER_SECOND2 = 1.f / 16384.f * GRAVITY_EARTH;                                                                //  From MPU-9150 register map, with setting on                                                                //  highest resolution = +/- 2G                _lastAcceleration = glm::vec3(-accelData[2], -accelData[1], -accelData[0]) * LSB_TO_METERS_PER_SECOND2;                  short gyroData[3];        mpu_get_gyro_reg(gyroData, 0);                //  Convert the integer rates to floats        const float LSB_TO_DEGREES_PER_SECOND = 1.f / 16.4f;     //  From MPU-9150 register map, 2000 deg/sec.        glm::vec3 rotationRates;        rotationRates[0] = ((float) -gyroData[2]) * LSB_TO_DEGREES_PER_SECOND;        rotationRates[1] = ((float) -gyroData[1]) * LSB_TO_DEGREES_PER_SECOND;        rotationRates[2] = ((float) -gyroData[0]) * LSB_TO_DEGREES_PER_SECOND;              short compassData[3];        mpu_get_compass_reg(compassData, 0);              // Convert integer values to floats, update extents        _lastCompass = glm::vec3(compassData[2], -compassData[0], -compassData[1]);                // update and subtract the long term average        _averageRotationRates = (1.f - 1.f/(float)LONG_TERM_RATE_SAMPLES) * _averageRotationRates +                1.f/(float)LONG_TERM_RATE_SAMPLES * rotationRates;        rotationRates -= _averageRotationRates;         // compute the angular acceleration        glm::vec3 angularAcceleration = (deltaTime < EPSILON) ? glm::vec3() : (rotationRates - _lastRotationRates) / deltaTime;        _lastRotationRates = rotationRates;                //  Update raw rotation estimates        glm::quat estimatedRotation = glm::quat(glm::radians(_estimatedRotation)) *            glm::quat(glm::radians(deltaTime * _lastRotationRates));                //  Update acceleration estimate: first, subtract gravity as rotated into current frame        _estimatedAcceleration = (totalSamples < GRAVITY_SAMPLES) ? glm::vec3() :            _lastAcceleration - glm::inverse(estimatedRotation) * _gravity;                // update and subtract the long term average        _averageAcceleration = (1.f - 1.f/(float)LONG_TERM_RATE_SAMPLES) * _averageAcceleration +                1.f/(float)LONG_TERM_RATE_SAMPLES * _estimatedAcceleration;        _estimatedAcceleration -= _averageAcceleration;                //  Consider updating our angular velocity/acceleration to linear acceleration mapping        if (glm::length(_estimatedAcceleration) > EPSILON &&                (glm::length(_lastRotationRates) > EPSILON || glm::length(angularAcceleration) > EPSILON)) {            // compute predicted linear acceleration, find error between actual and predicted            glm::vec3 predictedAcceleration = _angularVelocityToLinearAccel * _lastRotationRates +                _angularAccelToLinearAccel * angularAcceleration;            glm::vec3 error = _estimatedAcceleration - predictedAcceleration;                        // the "error" is actually what we want: the linear acceleration minus rotational influences            _estimatedAcceleration = error;                        // adjust according to error in each dimension, in proportion to input magnitudes            for (int i = 0; i < 3; i++) {                if (fabsf(error[i]) < EPSILON) {                    continue;                }                const float LEARNING_RATE = 0.001f;                float rateSum = fabsf(_lastRotationRates.x) + fabsf(_lastRotationRates.y) + fabsf(_lastRotationRates.z);                if (rateSum > EPSILON) {                    for (int j = 0; j < 3; j++) {                        float proportion = LEARNING_RATE * fabsf(_lastRotationRates[j]) / rateSum;                        if (proportion > EPSILON) {                            _angularVelocityToLinearAccel[j][i] += error[i] * proportion / _lastRotationRates[j];                        }                    }                }                float accelSum = fabsf(angularAcceleration.x) + fabsf(angularAcceleration.y) + fabsf(angularAcceleration.z);                if (accelSum > EPSILON) {                    for (int j = 0; j < 3; j++) {                        float proportion = LEARNING_RATE * fabsf(angularAcceleration[j]) / accelSum;                        if (proportion > EPSILON) {                            _angularAccelToLinearAccel[j][i] += error[i] * proportion / angularAcceleration[j];                        }                    }                                }            }        }                // rotate estimated acceleration into global rotation frame        _estimatedAcceleration = estimatedRotation * _estimatedAcceleration;                //  Update estimated position and velocity        float const DECAY_VELOCITY = 0.975f;        float const DECAY_POSITION = 0.975f;        _estimatedVelocity += deltaTime * _estimatedAcceleration;        _estimatedPosition += deltaTime * _estimatedVelocity;        _estimatedVelocity *= DECAY_VELOCITY;                //  Attempt to fuse gyro position with webcam position        Webcam* webcam = Application::getInstance()->getWebcam();        if (webcam->isActive()) {            const float WEBCAM_POSITION_FUSION = 0.5f;            _estimatedPosition = glm::mix(_estimatedPosition, webcam->getEstimatedPosition(), WEBCAM_POSITION_FUSION);                       } else {            _estimatedPosition *= DECAY_POSITION;        }                    //  Accumulate a set of initial baseline readings for setting gravity        if (totalSamples == 0) {            _gravity = _lastAcceleration;        }         else {            if (totalSamples < GRAVITY_SAMPLES) {                _gravity = glm::mix(_gravity, _lastAcceleration, 1.0f / GRAVITY_SAMPLES);                                //  North samples start later, because the initial compass readings are screwy                int northSample = totalSamples - (GRAVITY_SAMPLES - NORTH_SAMPLES);                if (northSample == 0) {                    _north = _lastCompass;                                    } else if (northSample > 0) {                    _north = glm::mix(_north, _lastCompass, 1.0f / NORTH_SAMPLES);                }            } else {                //  Use gravity reading to do sensor fusion on the pitch and roll estimation                estimatedRotation = safeMix(estimatedRotation,                    rotationBetween(estimatedRotation * _lastAcceleration, _gravity) * estimatedRotation,                    1.0f / ACCELERATION_SENSOR_FUSION_SAMPLES);                                //  Update the compass extents                _compassMinima = glm::min(_compassMinima, _lastCompass);                _compassMaxima = glm::max(_compassMaxima, _lastCompass);                        //  Same deal with the compass heading                estimatedRotation = safeMix(estimatedRotation,                    rotationBetween(estimatedRotation * recenterCompass(_lastCompass),                        recenterCompass(_north)) * estimatedRotation,                    1.0f / COMPASS_SENSOR_FUSION_SAMPLES);            }        }                _estimatedRotation = safeEulerAngles(estimatedRotation);                 totalSamples++;    }         if (initialSamples == totalSamples) {                timeval now;        gettimeofday(&now, NULL);                if (diffclock(&lastGoodRead, &now) > NO_READ_MAXIMUM_MSECS) {            qDebug("No data - Shutting down SerialInterface.\n");            resetSerial();        }    } else {        gettimeofday(&lastGoodRead, NULL);    }#endif} void SerialInterface::resetAverages() {    totalSamples = 0;    _gravity = glm::vec3(0, 0, 0);    _averageRotationRates = glm::vec3(0, 0, 0);    _averageAcceleration = glm::vec3(0, 0, 0);    _lastRotationRates = glm::vec3(0, 0, 0);    _estimatedRotation = glm::vec3(0, 0, 0);    _estimatedPosition = glm::vec3(0, 0, 0);    _estimatedVelocity = glm::vec3(0, 0, 0);    _estimatedAcceleration = glm::vec3(0, 0, 0);} void SerialInterface::resetSerial() {#ifndef _WIN32    resetAverages();    _active = false;    gettimeofday(&lastGoodRead, NULL);#endif} glm::vec3 SerialInterface::recenterCompass(const glm::vec3& compass) {    // compensate for "hard iron" distortion by subtracting the midpoint on each axis; see    // http://www.sensorsmag.com/sensors/motion-velocity-displacement/compensating-tilt-hard-iron-and-soft-iron-effects-6475    return (compass - (_compassMinima + _compassMaxima) * 0.5f) / (_compassMaxima - _compassMinima);}