AMiRo-OS

#include "userthread.h"

#include "global.hpp"

#include <array>

#include <chprintf.h>

#include <cmath>

using namespace amiro;

extern Global global;

volatile UserThread::State current_state;

volatile UserThread::State next_state;

types::kinematic kinematic;

namespace obstacle_avoidance {

uint16_t constexpr proxThresholdLow = 0x0000;

uint16_t constexpr proxThresholdHigh = 0x1000;

uint16_t constexpr proxRange = proxThresholdHigh - proxThresholdLow;

std::array< std::array<float, 2>, 8> constexpr namMatrix = {

    /*                              x     w_z */

    std::array<float, 2>/* SSW */{ 0.00f,  0.00f},

    std::array<float, 2>/* WSW */{ 0.25f, -0.25f},

    std::array<float, 2>/* WNW */{-0.75f, -0.50f},

    std::array<float, 2>/* NNW */{-0.75f, -1.00f},

    std::array<float, 2>/* NNE */{-0.75f,  1.00f},

    std::array<float, 2>/* ENE */{-0.75f,  0.50f},

    std::array<float, 2>/* ESE */{ 0.25f,  0.25f},

    std::array<float, 2>/* SSE */{ 0.00f,  0.00f}

};

uint32_t constexpr baseTranslation = 100e3; // 2cm/s

uint32_t constexpr baseRotation = 1e6; // 1rad/s

types::kinematic constexpr defaultKinematic = {

    /*  x  [µm/s]   */ baseTranslation,

    /*  y  [µm/s]   */ 0,

    /*  z  [µm/s]   */ 0,

    /* w_x [µrad/s] */ 0,

    /* w_y [µrad/s] */ 0,

    /* w_z [µrad/s] */ 0

};

inline uint8_t ProxId2LedId(const uint8_t proxId) {

    return (proxId < 4) ? proxId+4 : proxId-4;

}

Color Prox2Color(const float prox) {

  float p = 0.0f;

  if (prox < 0.5f) {

    p = 2.0f * prox;

    return Color(0x00, p*0xFF, (1.0f-p)*0xFF);

  } else {

    p = 2.0f * (prox - 0.5f);

    return Color(p*0xFF, (1.0f-p)*0xFF, 0x00);

  }

}

} /* namespace obstacle_avoidance */

namespace wii_steering {

BluetoothWiimote wiimote(&global.wt12, RX_TX);

BluetoothSerial btserial(&global.wt12, RX_TX);

float deadzone;

char bt_address[18] = {'\0'};

float wiimoteCalib[3] = {0.0f};

uint32_t constexpr maxTranslation = 500e3;

uint32_t constexpr maxRotation = 3.1415927f * 1000000.0f * 2.0f;

}

UserThread::UserThread() :

  chibios_rt::BaseStaticThread<USER_THREAD_STACK_SIZE>()

{

}

UserThread::~UserThread()

{

}

msg_t

UserThread::main()

{

  /*

   * initialize some variables

   */

  current_state = IDLE;

  /*

   * set all LEDs black (off)

   */

  for (uint8_t led = 0; led < 8; ++led) {

    global.robot.setLightColor(led, Color(Color::BLACK));

  }

  /*

   * thread loop

   */

  while (!this->shouldTerminate()) {

    /*

     * handle changes of the state

     */

    if (next_state != current_state) {

      switch (current_state) {

        case IDLE:

        {

          if (next_state == OBSTACLE_AVOIDANCE) {

            // set all LEDs to white for one second

            for (uint8_t led = 0; led < 8; ++led) {

              global.robot.setLightColor(led, Color(Color::WHITE));

            }

            this->sleep(MS2ST(1000));

            for (uint8_t led = 0; led < 8; ++led) {

              global.robot.setLightColor(led, Color(Color::BLACK));

            }

          }

          /* if (this->next_state == WII_STEERING) */ else {

            // setup bluetooth

            wii_steering::wiimote.bluetoothWiimoteListen(wii_steering::bt_address);

            wii_steering::btserial.bluetoothSerialListen("ALL");

            // set LEDs: front = green; rear = red; sides = blue

            global.robot.setLightColor(constants::LightRing::LED_NNW, Color(Color::GREEN));

            global.robot.setLightColor(constants::LightRing::LED_NNE, Color(Color::GREEN));

            global.robot.setLightColor(constants::LightRing::LED_SSW, Color(Color::RED));

            global.robot.setLightColor(constants::LightRing::LED_SSE, Color(Color::RED));

            global.robot.setLightColor(constants::LightRing::LED_WNW, Color(Color::BLUE));

            global.robot.setLightColor(constants::LightRing::LED_WSW, Color(Color::BLUE));

            global.robot.setLightColor(constants::LightRing::LED_ENE, Color(Color::BLUE));

            global.robot.setLightColor(constants::LightRing::LED_ESE, Color(Color::BLUE));

            chprintf((BaseSequentialStream*)&global.sercanmux1, "press buttons '1' and '2' to connect\n");

          }

          break;

        }

        case OBSTACLE_AVOIDANCE:

        {

          if (next_state == IDLE) {

            // stop the robot

            kinematic = {0, 0, 0, 0, 0, 0};

            global.robot.setTargetSpeed(kinematic);

            // set all LEDs to white for one second

            for (uint8_t led = 0; led < 8; ++led) {

              global.robot.setLightColor(led, Color(Color::WHITE));

            }

            this->sleep(MS2ST(1000));

            for (uint8_t led = 0; led < 8; ++led) {

              global.robot.setLightColor(led, Color(Color::BLACK));

            }

          }

          /* if (this->next_state == WII_STEERING) */ else {

            // must turn off obstacle avoidance first

            chprintf((BaseSequentialStream*)&global.sercanmux1, "ERROR: turn off obstacle avoidance first!\n");

            next_state = OBSTACLE_AVOIDANCE;

          }

          break;

        }

        case WII_STEERING: {

          if (next_state == IDLE) {

            // stop the robot

            kinematic = {0, 0, 0, 0, 0, 0};

            global.robot.setTargetSpeed(kinematic);

            // disconnect from Wiimote controller

            wii_steering::wiimote.bluetoothWiimoteDisconnect(wii_steering::bt_address);

            wii_steering::btserial.bluetoothSerialStop();

            wii_steering::wiimote.bluetoothWiimoteStop();

            // set all LEDs to black

            for (uint8_t led = 0; led < 8; ++led) {

              global.robot.setLightColor(led, Color(Color::BLACK));

            }

          }

          /* if (this->next_state == OBSTACLE_AVOIDANCE) */ else {

            // must turn off wii steering first

            chprintf((BaseSequentialStream*)&global.sercanmux1, "ERROR: turn off wii steering first!\n");

            next_state = WII_STEERING;

          }

          break;

        }

      }

      current_state = next_state;

    }

    // sleep here so the loop is executed as quickly as possible

    this->sleep(CAN::UPDATE_PERIOD);

    /*

     * exeute behaviour depending on the current state

     */

    switch (current_state) {

      case IDLE:

      {

        // read touch sensors

        if (global.mpr121.getButtonStatus() == 0x0F) {

          next_state = OBSTACLE_AVOIDANCE;

        }

        break;

      }

      case OBSTACLE_AVOIDANCE:

      {

        // read touch sensors

        if (global.mpr121.getButtonStatus() == 0x0F) {

          next_state = IDLE;

          break;

        }

        // initialize some variables

        uint8_t sensor = 0;

        std::array<uint16_t, 8> proximity;

        std::array<float, 8> proxNormalized;

        float factor_x = 0.0f;

        float factor_wz = 0.0f;

        // read proximity values

        for (sensor = 0; sensor < 8; ++sensor) {

          proximity[sensor] = global.vcnl4020[sensor].getProximityScaledWoOffset();

        }

        // normalize proximity values

        for (sensor = 0; sensor < 8; ++sensor) {

          register uint16_t prox = proximity[sensor];

          // limit to high treshold

          if (prox > obstacle_avoidance::proxThresholdHigh)

              prox = obstacle_avoidance::proxThresholdHigh;

          // limit to low threshold

          else if (prox < obstacle_avoidance::proxThresholdLow)

              prox = obstacle_avoidance::proxThresholdLow;

          // apply low threshold

          prox -= obstacle_avoidance::proxThresholdLow;

          // normalize to [0, 1]

          proxNormalized[sensor] = float(prox) / float(obstacle_avoidance::proxRange);

        }

        // map the sensor values to the top LEDs

        for (sensor = 0; sensor < 8; ++sensor) {

          global.robot.setLightColor(obstacle_avoidance::ProxId2LedId(sensor), obstacle_avoidance::Prox2Color(proxNormalized[sensor]));

        }

        // evaluate NAM

        for (sensor = 0; sensor < 8; ++sensor) {

          factor_x += proxNormalized[sensor] * obstacle_avoidance::namMatrix[sensor][0];

          factor_wz += proxNormalized[sensor] * obstacle_avoidance::namMatrix[sensor][1];

        }

        // set motor commands

        kinematic = obstacle_avoidance::defaultKinematic;

        kinematic.x += (factor_x * obstacle_avoidance::baseTranslation) + 0.5f;

        kinematic.w_z += (factor_wz * obstacle_avoidance::baseRotation) + 0.5f;

        global.robot.setTargetSpeed(kinematic);

        break;

      }

      case WII_STEERING:

      {

        // if not yet connected to the Wiimote controller

        if (!wii_steering::wiimote.bluetoothWiimoteIsConnected()) {

          // try to connect

          chprintf((BaseSequentialStream*)&global.sercanmux1, "connecting...\n");

          wii_steering::wiimote.bluetoothWiimoteConnect(wii_steering::bt_address);

          if (wii_steering::wiimote.bluetoothWiimoteIsConnected()) {

            chprintf((BaseSequentialStream*)&global.sercanmux1, "connection established\n");

            chprintf((BaseSequentialStream*)&global.sercanmux1, "\n");

            chprintf((BaseSequentialStream*)&global.sercanmux1, "Wiimote control:\n");

            chprintf((BaseSequentialStream*)&global.sercanmux1, "\tpress 'home' to calibrate\n");

            chprintf((BaseSequentialStream*)&global.sercanmux1, "\thold 'A' to steer\n");

          }

        }

        // steer AMiRo using the Wiimote controller like a joystick

        else {

          // initialize some variables

          float wiimoteAcc[3] = {0.0f, 0.0f, 0.0f};

          // get Wiimote accelerometer data

          wiimoteAcc[0] = wii_steering::wiimote.getAccelerometer()->x_axis;

          wiimoteAcc[1] = wii_steering::wiimote.getAccelerometer()->y_axis;

          wiimoteAcc[2] = wii_steering::wiimote.getAccelerometer()->z_axis;

          // calibrate accelerometer offset

          if (wii_steering::wiimote.getButtons()->home) {

            wii_steering::wiimoteCalib[0] = wiimoteAcc[0];

            wii_steering::wiimoteCalib[1] = wiimoteAcc[1] + 100.0f;

            wii_steering::wiimoteCalib[2] = wiimoteAcc[2];

            chprintf((BaseSequentialStream*)&global.sercanmux1, "accelerometer calibrated:\n");

            chprintf((BaseSequentialStream*)&global.sercanmux1, "\tX = %d\n", (int32_t)wii_steering::wiimoteCalib[0]);

            chprintf((BaseSequentialStream*)&global.sercanmux1, "\tY = %d\n", (int32_t)wii_steering::wiimoteCalib[1]);

            chprintf((BaseSequentialStream*)&global.sercanmux1, "\tZ = %d\n", (int32_t)wii_steering::wiimoteCalib[2]);

          }

          for (uint8_t axis = 0; axis < 3; ++axis) {

            // apply calibration values

            wiimoteAcc[axis] -= wii_steering::wiimoteCalib[axis];

            // normalize to (-1, 1)

            wiimoteAcc[axis] /= 100.0f;

            // limit to 1G

            if (wiimoteAcc[axis] > 1.0f) {

              wiimoteAcc[axis] = 1.0f;

            } else if (wiimoteAcc[axis] < -1.0f) {

              wiimoteAcc[axis] = -1.0f;

            }

            // apply deadzone

            if (std::fabs(wiimoteAcc[axis]) < wii_steering::deadzone) {

              wiimoteAcc[axis] = 0.0f;

            }

            /*

             * the value is now in (-1 .. -deazone, 0, deadzone .. 1)

             * note the gaps [-deadzone .. 0] and [0 .. deadzone]

             */

            // normalize (deadzone, 1) to (0, 1) and (-1, -deadzone) tpo (-1, 0)

            if (wiimoteAcc[axis] > 0) {

              wiimoteAcc[axis] -= wii_steering::deadzone;

            } else if (wiimoteAcc[axis] < 0){

              wiimoteAcc[axis] += wii_steering::deadzone;

            }

            wiimoteAcc[axis] *= (1.0f / (1.0f - wii_steering::deadzone));

          }

          // only move when A is pressed

          if (wii_steering::wiimote.getButtons()->A) {

            // set kinematic relaive to maximum speeds

            kinematic.x = wii_steering::maxTranslation * wiimoteAcc[2];

            kinematic.w_z = wii_steering::maxRotation * wiimoteAcc[0] * ((wiimoteAcc[2] < 0.0f) ? 1.0f : -1.0f);

          } else {

            kinematic = {0, 0, 0, 0, 0, 0};

          }

          // set speed

          global.robot.setTargetSpeed(kinematic);

        }

        break;

      }

    }

  }

  // stop the robot

  kinematic = {0, 0, 0, 0, 0, 0};

  global.robot.setTargetSpeed(kinematic);

  return RDY_OK;

}

void

UserThread::setNextState(const UserThread::State state)

{

  next_state = state;

  return;

}

UserThread::State

UserThread::getCurrenState() const

{

  return current_state;

}

msg_t

UserThread::setWiiAddress(const char* address)

{

  if (strlen(address) != 17) {

    return RDY_RESET;

  }

  else {

    strcpy(wii_steering::bt_address, address);

    return RDY_OK;

  }

}

float

UserThread::setWiiDeadzone(const float deadzone)

{

  // check for negative value and limit to zero

  float dz = (deadzone < 0.0f) ? 0.0f : deadzone;

  // if value is >1, range is assumed to be (0, 100)

  if (dz > 1.0f) {

    // limit to 100

    if (dz > 100.0f) {

      dz = 100.0f;

    }

    dz /= 100.0f;

  }

  // set value and return it

  wii_steering::deadzone = dz;

  return dz;

}