This twist on a carnival game is intended to trick its user into thinking they have the possibility of sleeping. As the wheel is spun an accelerometer measures the wheel’s position, sensing whether or not the wheel has landed on the “sleep” or “get fooked” section.  Whenever the wheel is not in the “get fooked” position, a hidden motor attempts to spin the wheel back to the “get fooked” position, ensuring that no matter how the wheel initially lands, the user’s fate will always be of the less pleasant variety.

 

Code


// I2C device class (I2Cdev) demonstration Arduino sketch for MPU6050 class using DMP (MotionApps v2.0)
// 6/21/2012 by Jeff Rowberg <jeff@rowberg.net>
// Updates should (hopefully) always be available at https://github.com/jrowberg/i2cdevlib
//
// Changelog:
// 2013-05-08 - added seamless Fastwire support
// - added note about gyro calibration
// 2012-06-21 - added note about Arduino 1.0.1 + Leonardo compatibility error
// 2012-06-20 - improved FIFO overflow handling and simplified read process
// 2012-06-19 - completely rearranged DMP initialization code and simplification
// 2012-06-13 - pull gyro and accel data from FIFO packet instead of reading directly
// 2012-06-09 - fix broken FIFO read sequence and change interrupt detection to RISING
// 2012-06-05 - add gravity-compensated initial reference frame acceleration output
// - add 3D math helper file to DMP6 example sketch
// - add Euler output and Yaw/Pitch/Roll output formats
// 2012-06-04 - remove accel offset clearing for better results (thanks Sungon Lee)
// 2012-06-01 - fixed gyro sensitivity to be 2000 deg/sec instead of 250
// 2012-05-30 - basic DMP initialization working

/* ============================================
I2Cdev device library code is placed under the MIT license
Copyright (c) 2012 Jeff Rowberg

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
===============================================
*/

// I2Cdev and MPU6050 must be installed as libraries, or else the .cpp/.h files
// for both classes must be in the include path of your project
#include "I2Cdev.h"

#include "MPU6050_6Axis_MotionApps20.h"
//#include "MPU6050.h" // not necessary if using MotionApps include file

// Arduino Wire library is required if I2Cdev I2CDEV_ARDUINO_WIRE implementation
// is used in I2Cdev.h
#if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
#include "Wire.h"
#endif

MPU6050 mpu;

// Motor and LED pins
#define MOT_B1_PIN 10
#define MOT_B2_PIN 11
#define LED_PIN 13 // (Arduino is 13, Teensy is 11, Teensy++ is 6)
bool blinkState = false;

// MPU control/status vars
bool dmpReady = false; // set true if DMP init was successful
uint8_t mpuIntStatus; // holds actual interrupt status byte from MPU
uint8_t devStatus; // return status after each device operation (0 = success, !0 = error)
uint16_t packetSize; // expected DMP packet size (default is 42 bytes)
uint16_t fifoCount; // count of all bytes currently in FIFO
uint8_t fifoBuffer[64]; // FIFO storage buffer

// orientation/motion vars
Quaternion q; // [w, x, y, z] quaternion container
VectorInt16 aa; // [x, y, z] accel sensor measurements
VectorInt16 aaReal; // [x, y, z] gravity-free accel sensor measurements
VectorInt16 aaWorld; // [x, y, z] world-frame accel sensor measurements
VectorFloat gravity; // [x, y, z] gravity vector
float euler[3]; // [psi, theta, phi] Euler angle container
float ypr[3]; // [yaw, pitch, roll] yaw/pitch/roll container and gravity vector

// state variables
static int state_ind = 0;
float prev_yaw = 1000;

// ================================================================
// === INTERRUPT DETECTION ROUTINE ===
// ================================================================

volatile bool mpuInterrupt = false; // indicates whether MPU interrupt pin has gone high
void dmpDataReady() {
mpuInterrupt = true;
}

// ================================================================
// === HELPER FUNCTIONS ===
// ================================================================

// from https://courses.ideate.cmu.edu/16-223/f2018/text/lib/WheelDrive.html#wheeldrive-doxygen
void set_motor_pwm(int pwm)
{
if (pwm < 0) { // reverse speeds
analogWrite(MOT_B1_PIN, -pwm);
digitalWrite(MOT_B2_PIN, LOW);

} else { // stop or forward
digitalWrite(MOT_B1_PIN, LOW);
analogWrite(MOT_B2_PIN, pwm);
}
}

// ================================================================
// === INITIAL SETUP ===
// ================================================================

void setup() {
// join I2C bus (I2Cdev library doesn't do this automatically)
#if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
Wire.begin();
TWBR = 24; // 400kHz I2C clock (200kHz if CPU is 8MHz)
#elif I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_FASTWIRE
Fastwire::setup(400, true);
#endif

// Initialize motor pins
pinMode(MOT_B1_PIN, OUTPUT);
pinMode(MOT_B2_PIN, OUTPUT);
digitalWrite(MOT_B1_PIN, LOW);
digitalWrite(MOT_B2_PIN, LOW);

// initialize serial communication
// (115200 chosen because it is required for Teapot Demo output, but it's
// really up to you depending on your project)
Serial.begin(115200);
while (!Serial); // wait for Leonardo enumeration, others continue immediately

// NOTE: 8MHz or slower host processors, like the Teensy @ 3.3v or Ardunio
// Pro Mini running at 3.3v, cannot handle this baud rate reliably due to
// the baud timing being too misaligned with processor ticks. You must use
// 38400 or slower in these cases, or use some kind of external separate
// crystal solution for the UART timer.

// initialize device
Serial.println(F("Initializing I2C devices..."));
mpu.initialize();

// verify connection
Serial.println(F("Testing device connections..."));
Serial.println(mpu.testConnection() ? F("MPU6050 connection successful") : F("MPU6050 connection failed"));

// wait for ready
// Serial.println(F("\nSend any character to begin DMP programming and demo: "));
// while (Serial.available() && Serial.read()); // empty buffer
// while (!Serial.available()); // wait for data
// while (Serial.available() && Serial.read()); // empty buffer again

// load and configure the DMP
Serial.println(F("Initializing DMP..."));
devStatus = mpu.dmpInitialize();

// supply your own gyro offsets here, scaled for min sensitivity
mpu.setXGyroOffset(220); // 220 default
mpu.setYGyroOffset(76);
mpu.setZGyroOffset(-85);
mpu.setZAccelOffset(1788); // 1688 factory default for my test chip

// make sure it worked (returns 0 if so)
if (devStatus == 0) {
// turn on the DMP, now that it's ready
Serial.println(F("Enabling DMP..."));
mpu.setDMPEnabled(true);

// enable Arduino interrupt detection
Serial.println(F("Enabling interrupt detection (Arduino external interrupt 0)..."));
attachInterrupt(0, dmpDataReady, RISING);
mpuIntStatus = mpu.getIntStatus();

// set our DMP Ready flag so the main loop() function knows it's okay to use it
Serial.println(F("DMP ready! Waiting for first interrupt..."));
dmpReady = true;

// get expected DMP packet size for later comparison
packetSize = mpu.dmpGetFIFOPacketSize();
} else {
// ERROR!
// 1 = initial memory load failed
// 2 = DMP configuration updates failed
// (if it's going to break, usually the code will be 1)
Serial.print(F("DMP Initialization failed (code "));
Serial.print(devStatus);
Serial.println(F(")"));
}

// configure LED for output
pinMode(LED_PIN, OUTPUT);
}

// ================================================================
// === MAIN PROGRAM LOOP ===
// ================================================================

void loop() {
// if programming failed, don't try to do anything
if (!dmpReady) return;

// wait for MPU interrupt or extra packet(s) available
while (!mpuInterrupt && fifoCount < packetSize) {
// other program behavior stuff here
// .
// .
// .
// if you are really paranoid you can frequently test in between other
// stuff to see if mpuInterrupt is true, and if so, "break;" from the
// while() loop to immediately process the MPU data
// .
// .
// .
}

// reset interrupt flag and get INT_STATUS byte
mpuInterrupt = false;
mpuIntStatus = mpu.getIntStatus();

// get current FIFO count
fifoCount = mpu.getFIFOCount();

// check for overflow (this should never happen unless our code is too inefficient)
if ((mpuIntStatus & 0x10) || fifoCount == 1024) {
// reset so we can continue cleanly
mpu.resetFIFO();
Serial.println(F("FIFO overflow!"));

// otherwise, check for DMP data ready interrupt (this should happen frequently)
} else if (mpuIntStatus & 0x02) {
// wait for correct available data length, should be a VERY short wait
while (fifoCount < packetSize) fifoCount = mpu.getFIFOCount();

// read a packet from FIFO
mpu.getFIFOBytes(fifoBuffer, packetSize);

// track FIFO count here in case there is > 1 packet available
// (this lets us immediately read more without waiting for an interrupt)
fifoCount -= packetSize;

mpu.dmpGetQuaternion(&q, fifoBuffer);
mpu.dmpGetGravity(&gravity, &q);
mpu.dmpGetYawPitchRoll(ypr, &q, &gravity);
float yaw = ypr[0];
Serial.print("yaw\t");
Serial.println(yaw);

if (prev_yaw == 1000) prev_yaw = yaw;

Serial.print("state:\t");
Serial.println(state_ind);

float yaw_diff = abs(yaw - prev_yaw)*(180/M_PI);
Serial.print("yaw_diff\t");
Serial.println(yaw_diff);

switch (state_ind){
case 0:
digitalWrite(MOT_B1_PIN, LOW);
digitalWrite(MOT_B2_PIN, LOW);
if (yaw_diff > 1) state_ind = 1;
break;
case 1:
digitalWrite(MOT_B1_PIN, LOW);
digitalWrite(MOT_B2_PIN, LOW);
if (yaw_diff < 1) state_ind = 2;
break;
case 2:
float p_const = 1;
float diff = 0 - yaw;
diff = atan2(sin(diff), cos(diff));
Serial.print("diff\t");
Serial.println(diff);

int std_diff = int(p_const * float(diff) * (255/(2*M_PI)));
Serial.print("std_diff\t");
Serial.println(std_diff);
set_motor_pwm(std_diff);

if (abs(std_diff) < 10 && yaw_diff < 1) state_ind = 0;
break;
}

prev_yaw = yaw;

// blink LED to indicate activity
blinkState = !blinkState;
digitalWrite(LED_PIN, blinkState);
}
}

This sketch utilizes code from this exercise.