overte-HifiExperiments/interface/src/SerialInterface.cpp
2013-06-11 15:47:05 -07:00

367 lines
15 KiB
C++

//
// 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 "SharedUtil.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 values
const 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 port
void 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 lines
void 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 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.
glm::vec3 rotationRates;
rotationRates[0] = ((float) -pitchRate) * LSB_TO_DEGREES_PER_SECOND;
rotationRates[1] = ((float) -yawRate) * LSB_TO_DEGREES_PER_SECOND;
rotationRates[2] = ((float) -rollRate) * LSB_TO_DEGREES_PER_SECOND;
// compute the angular acceleration
glm::vec3 angularAcceleration = (deltaTime < EPSILON) ? glm::vec3() : (rotationRates - _lastRotationRates) / deltaTime;
_lastRotationRates = rotationRates;
_averageRotationRates = (1.f - 1.f/(float)LONG_TERM_RATE_SAMPLES) * _averageRotationRates +
1.f/(float)LONG_TERM_RATE_SAMPLES * _lastRotationRates;
printLog("r: %g %g %g\n", _averageRotationRates.x, _averageRotationRates.y, _averageRotationRates.z);
// 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;
_averageAcceleration = (1.f - 1.f/(float)LONG_TERM_RATE_SAMPLES) * _averageAcceleration +
1.f/(float)LONG_TERM_RATE_SAMPLES * _estimatedAcceleration;
printLog("a: %g %g %g\n", _averageAcceleration.x, _averageAcceleration.y, _averageAcceleration.z);
// 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 = 0.95f;
float const DECAY_POSITION = 0.95f;
_estimatedVelocity += deltaTime * _estimatedAcceleration;
_estimatedPosition += deltaTime * _estimatedVelocity;
_estimatedVelocity *= DECAY_VELOCITY;
_estimatedPosition *= DECAY_POSITION;
// Accumulate a set of initial baseline readings for setting gravity
if (totalSamples == 0) {
_gravity = _lastAcceleration;
}
else {
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 = 0.999f;
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);
_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() {
#ifdef __APPLE__
resetAverages();
active = false;
gettimeofday(&lastGoodRead, NULL);
#endif
}