////  SerialInterface.cpp//  2012 by Philip Rosedale for High Fidelity Inc.////  Read interface data from the gyros/accelerometer Invensense board using the SerialUSB// #include "SerialInterface.h"#include "Util.h"#include <glm/gtx/vector_angle.hpp>#include <math.h> #ifdef __APPLE__#include <regex.h>#include <sys/time.h>#include <string>#endif const short NO_READ_MAXIMUM_MSECS = 3000;const int GRAVITY_SAMPLES = 60;                     //  Use the first few samples to baseline valuesconst int SENSOR_FUSION_SAMPLES = 20;const int LONG_TERM_RATE_SAMPLES = 1000;             const bool USING_INVENSENSE_MPU9150 = 1; void SerialInterface::pair() {    #ifdef __APPLE__    // 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*    if((devDir = opendir("/dev"))) {        while((entry = readdir(devDir))) {            regcomp(&regex, "tty\\.usb", REG_EXTENDED|REG_NOSUB);            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) {#ifdef __APPLE__    _serialDescriptor = open(portname, O_RDWR | O_NOCTTY | O_NDELAY);        printLog("Opening SerialUSB %s: ", portname);        if (_serialDescriptor == -1) {        printLog("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);                // there are extra commands to send to the invensense when it fires up                // this takes it out of SLEEP        write(_serialDescriptor, "WR686B01\n", 9);                // delay after the wakeup        usleep(10000);                // this disables streaming so there's no garbage data on reads        write(_serialDescriptor, "SD\n", 3);                // delay after disabling streaming        usleep(10000);                // flush whatever was produced by the last two commands        tcflush(_serialDescriptor, TCIOFLUSH);    }        printLog("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)((_lastAcceleration.x - _gravity.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)((_lastAcceleration.y - _gravity.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)((_lastAcceleration.z - _gravity.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 convertHexToInt(unsigned char* sourceBuffer, int& destinationInt) {    unsigned int byte[2];        for(int i = 0; i < 2; i++) {        sscanf((char*) sourceBuffer + 2 * i, "%2x", &byte[i]);    }        int16_t result = (byte[0] << 8);    result += byte[1];        destinationInt = result;}void SerialInterface::readData(float deltaTime) {#ifdef __APPLE__        int initialSamples = totalSamples;        if (USING_INVENSENSE_MPU9150) {         unsigned char sensorBuffer[36];                // ask the invensense for raw gyro data        write(_serialDescriptor, "RD683B0E\n", 9);        read(_serialDescriptor, sensorBuffer, 36);                int accelXRate, accelYRate, accelZRate;                convertHexToInt(sensorBuffer + 6, accelZRate);        convertHexToInt(sensorBuffer + 10, accelYRate);        convertHexToInt(sensorBuffer + 14, accelXRate);                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(-accelXRate, -accelYRate, -accelZRate) * LSB_TO_METERS_PER_SECOND2;                        int rollRate, yawRate, pitchRate;                convertHexToInt(sensorBuffer + 22, rollRate);        convertHexToInt(sensorBuffer + 26, yawRate);        convertHexToInt(sensorBuffer + 30, pitchRate);                //  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.        _lastRotationRates[0] = ((float) -pitchRate) * LSB_TO_DEGREES_PER_SECOND;        _lastRotationRates[1] = ((float) -yawRate) * LSB_TO_DEGREES_PER_SECOND;        _lastRotationRates[2] = ((float) -rollRate) * LSB_TO_DEGREES_PER_SECOND;         //  Update raw rotation estimates        glm::quat estimatedRotation = glm::quat(glm::radians(_estimatedRotation)) *            glm::quat(glm::radians(deltaTime * (_lastRotationRates - _averageRotationRates)));                //  Update estimated position and velocity        float const DECAY_VELOCITY = 0.95f;        float const DECAY_POSITION = 0.95f;        _estimatedVelocity += deltaTime * (_lastAcceleration - _averageAcceleration);        _estimatedPosition += deltaTime * _estimatedVelocity;        _estimatedVelocity *= DECAY_VELOCITY;        _estimatedPosition *= DECAY_POSITION;                        //  Accumulate a set of initial baseline readings for setting gravity        if (totalSamples == 0) {            _averageRotationRates = _lastRotationRates;            _averageAcceleration = _lastAcceleration;            _gravity = _lastAcceleration;        }         else {            //  Cumulate long term average to (hopefully) take DC bias out of rotation rates            _averageRotationRates = (1.f - 1.f / (float)LONG_TERM_RATE_SAMPLES) * _averageRotationRates                                    + 1.f / (float)LONG_TERM_RATE_SAMPLES * _lastRotationRates;            _averageAcceleration = (1.f - 1.f / (float)LONG_TERM_RATE_SAMPLES) * _averageAcceleration                                    + 1.f / (float)LONG_TERM_RATE_SAMPLES * _lastAcceleration;                        if (totalSamples < GRAVITY_SAMPLES) {                _gravity = (1.f - 1.f/(float)GRAVITY_SAMPLES) * _gravity +                1.f/(float)GRAVITY_SAMPLES * _lastAcceleration;            } else {                //  Use gravity reading to do sensor fusion on the pitch and roll estimation                estimatedRotation = safeMix(estimatedRotation,                    rotationBetween(estimatedRotation * _lastAcceleration, _gravity) * estimatedRotation,                    1.0f / SENSOR_FUSION_SAMPLES);                                //  Without a compass heading, always decay estimated Yaw slightly                const float YAW_DECAY = 0.995;                glm::vec3 forward = estimatedRotation * glm::vec3(0.0f, 0.0f, -1.0f);                estimatedRotation = safeMix(glm::angleAxis(glm::degrees(atan2f(forward.x, -forward.z)),                    glm::vec3(0.0f, 1.0f, 0.0f)) * estimatedRotation, estimatedRotation, YAW_DECAY);            }        }                _estimatedRotation = safeEulerAngles(estimatedRotation);                 totalSamples++;    }         if (initialSamples == totalSamples) {                timeval now;        gettimeofday(&now, NULL);                if (diffclock(&lastGoodRead, &now) > NO_READ_MAXIMUM_MSECS) {            printLog("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);} void SerialInterface::resetSerial() {#ifdef __APPLE__    resetAverages();    active = false;    gettimeofday(&lastGoodRead, NULL);#endif}