////  SerialInterface.cpp//  2012 by Philip Rosedale for High Fidelity Inc.////  Read interface data from the gyros/accelerometer board using SerialUSB////  Channels are received in the following order (integer 0-4096 based on voltage 0-3.3v)////  AIN 15:  Pitch Gyro (nodding your head 'yes')//  AIN 16:  Yaw Gyro (shaking your head 'no')//  AIN 17:  Roll Gyro (looking quizzical, tilting your head)//  AIN 18:  Lateral acceleration (moving from side-to-side in front of your monitor)//  AIN 19:  Up/Down acceleration (sitting up/ducking in front of your monitor)//  AIN 20:  Forward/Back acceleration (Toward or away from your monitor)// #include "SerialInterface.h" int serial_fd;const int MAX_BUFFER = 255;char serial_buffer[MAX_BUFFER];int serial_buffer_pos = 0;int samples_total = 0; const int ZERO_OFFSET = 2048; //  Init the serial port to the specified values int SerialInterface::init(char * portname, int baud){    serial_fd = open(portname, O_RDWR | O_NOCTTY | O_NDELAY);        if (serial_fd == -1) return -1;     //  Failed to open port        struct termios options;    tcgetattr(serial_fd,&options);    switch(baud)    {		case 9600: cfsetispeed(&options,B9600);			cfsetospeed(&options,B9600);			break;		case 19200: cfsetispeed(&options,B19200);			cfsetospeed(&options,B19200);			break;		case 38400: cfsetispeed(&options,B38400);			cfsetospeed(&options,B38400);			break;		case 115200: cfsetispeed(&options,B115200);			cfsetospeed(&options,B115200);			break;		default:cfsetispeed(&options,B9600);			cfsetospeed(&options,B9600);			break;    }    options.c_cflag |= (CLOCAL | CREAD);    options.c_cflag &= ~PARENB;    options.c_cflag &= ~CSTOPB;    options.c_cflag &= ~CSIZE;    options.c_cflag |= CS8;    tcsetattr(serial_fd,TCSANOW,&options);        //  Clear the measured and average channel data    for (int i = 1; i < NUM_CHANNELS; i++)    {        lastMeasured[i] = 0;        trailingAverage[i] = 0.0;    }    //  Clear serial input buffer    for (int i = 1; i < MAX_BUFFER; i++) {        serial_buffer[i] = ' ';    }      return 0;                   //  Init serial port was a success} //  Reset Trailing averages to the current measurementvoid SerialInterface::resetTrailingAverages() {    for (int i = 1; i < NUM_CHANNELS; i++)  trailingAverage[i] = lastMeasured[i];} //  Render the serial interface channel values onscreen as vertical linesvoid SerialInterface::renderLevels(int width, int height) {    int i;    int disp_x = 10;    const int GAP = 16;    char val[10];    for(i = 0; i < NUM_CHANNELS; i++)    {                //  Actual value        glLineWidth(2.0);        glColor4f(1, 1, 1, 1);        glBegin(GL_LINES);        glVertex2f(disp_x, height*0.95);        glVertex2f(disp_x, height*(0.25 + 0.75f*getValue(i)/4096));        glEnd();        //  Trailing Average value        glColor4f(1, 1, 0, 1);        glBegin(GL_LINES);        glVertex2f(disp_x + 2, height*0.95);        glVertex2f(disp_x + 2, height*(0.25 + 0.75f*getTrailingValue(i)/4096));        glEnd();                /*        glColor3f(1,0,0);        glBegin(GL_LINES);        glLineWidth(4.0);        glVertex2f(disp_x - 10, height*0.5 - getValue(i)/4096);        glVertex2f(disp_x + 10, height*0.5 - getValue(i)/4096);        glEnd();        */        sprintf(val, "%d", getValue(i));        drawtext(disp_x-GAP/2, (height*0.95)+2, 0.08, 90, 1.0, 0, val, 0, 1, 0);                disp_x += GAP;    }    //  Display Serial latency block    if (LED) {        glColor3f(1,0,0);        glBegin(GL_QUADS); {            glVertex2f(width - 100, height - 100);            glVertex2f(width, height - 100);            glVertex2f(width, height);            glVertex2f(width - 100, height);        }        glEnd();    } }void SerialInterface::readData() {    //  This array sets the rate of trailing averaging for each channel.    //  If the sensor rate is 100Hz, 0.001 will make the long term average a 10-second average    const float AVG_RATE[] =  {0.01, 0.01, 0.01, 0.01, 0.01, 0.01};    char bufchar[1];        while (read(serial_fd, &bufchar, 1) > 0)    {        //std::cout << bufchar[0];        serial_buffer[serial_buffer_pos] = bufchar[0];        serial_buffer_pos++;        //  Have we reached end of a line of input?        if ((bufchar[0] == '\n') || (serial_buffer_pos >= MAX_BUFFER))        {            std::string serialLine(serial_buffer, serial_buffer_pos-1);            //std::cout << serialLine << "\n";            int spot;            //int channel = 0;            std::string val;            for (int i = 0; i < NUM_CHANNELS + 2; i++) {                spot = serialLine.find_first_of(" ", 0);                if (spot != std::string::npos) {                    val = serialLine.substr(0,spot);                    //std::cout << val << "\n";                    if (i < NUM_CHANNELS) lastMeasured[i] = atoi(val.c_str());                    else samplesAveraged = atoi(val.c_str());                } else LED = atoi(serialLine.c_str());                serialLine = serialLine.substr(spot+1, serialLine.length() - spot - 1);            }            //std::cout << LED << "\n";                        for (int i = 0; i < NUM_CHANNELS; i++) {                if (samples_total > 0)                    trailingAverage[i] = (1.f - AVG_RATE[i])*trailingAverage[i] +                    AVG_RATE[i]*(float)lastMeasured[i];                else  trailingAverage[i] = (float)lastMeasured[i];                               }            samples_total++;            serial_buffer_pos = 0;        }    }}