1. Magic Wand Battle Game Team 53 Shanoon Martin, Jialin Sun, Manfei Wu

2. Introduction Combine the technology of gesture recognition and the concept of wide- range game Implement the wireless network in the game to make it portable and flexible

3. Block Diagram

4. Wands

5. Wand’s Workflow

6. Inertial Measurement Unit (IMU) Consist of 3-axis Gyroscope and 3- axis Accelerometer Accelerometer detects static and dynamic acceleration for tilt-sensing Gyroscope senses angular velocity for motion orientation

7. Filtering the IMU raw data Gyroscope is less susceptible to noise on short term, but has accumulated drift over time On long term, accelerometer data is sampled accurately because it does not drift Complementary Filter and Kalman Filter

8. Gesture Recognition Algorithm Limitation : Arduino Uno computational time and memory Better algorithm : Trajectory estimation algorithm and Bayesian network gesture recognnition Actual implemented algorithm : Perceptron Algorithm

9. Multiclass Perceptron Algorithm Single layer artificial neuron network Each data input vector is processed to be a feature vector f(x) Weight vector (w): a specialized vector that used for identification for each different class Activation: the dot product between w and f(x). The result determine which class the feature vector belong to

10. Hit Sensor Hit Sensor = Ultrasonic Receiver + Xbee + Arduino

11. Ultrasonic Receiver Schematic Three stages of amplifier(2N2222) and a comparator(LM386) Capacitors are added to get rid of DC components At the input of the comparator, if V+ > V-, output is high, otherwise it is low, so we will have a square wave output

12. Ultrasonic Transmitter MaxSonar EZ4 narrow beam Range: 0 - 5 meters Connect its Vdd and GND and it will send out ultrasonic wave automatically

13. Ultrasonic Receiver Output Oscilloscope output Arduino Serial Port Output

14. XBee S1 Wand Hit Sensor Receiver Xbee

16. Enable a wide range communication system Distance 100ft (30m) Set Transmitter Receiver XBee 1 XBee 2 ATID 40 ATID 40 Network ID ATMY 1 ATMY 2 Current ID ATDL 2 ATDL 1 Destination ID ATWR ATWR Save parameters ATCN ATCN Exit

17. Receive Message hello 0-100 Point-to-Point Communication System is Ready

18. Xbee Multiple Points Communication

19. Multiple Transmitters One Receiver Transmitters Receiver (Wand & Hit Sensor) ATID 40ATID 40 ATMY 1ATMY 2 ATDL 2 ATDL 1 ATWR ATCN

20. Main Receiver: Raspberry Pi A Receiver Xbee is connected Raspberry Pi with Xbee adapter Enable Serial input of Pi Download a Serial package Test code

21. Game Logic Used python, especially pygame Used several local variables to distinguish different incoming signals from IMU or ultrasonic receiver class player(): hp = 100 hit = 0 move = 0

22. User Interface Solder the PiTFT 2.8” touchscreen from Adafruit to female header Software: Install a new Kernel package over the Paspbian Test and then edit more files to make it auto-load

23. Wand’s Requirements and Verification Test on IMU calibration

24. Algorithm Correctness

25. Stable connectivity between Wands and Receiver  Transmit real time sampling data at once from the wand to the receiver, average data lost is less than 5%

26. Hit Sensor Requirements and Verifications Requirements: Ultrasonic receiver will receive ultrasonic wave 5 meters away At the longest distance, the receiver will have accuracy of 5cm Verifications: Set the transmitter and receiver in parallel and 5 meters away from each other Move the transmitter 5cm away from the line and see if the receiver gets any signals

27. Wireless Communication Requirements and Verifications Enable a wide range communication system Support the mesh Network for multiple users communication with one receiver

28. Power Budget First Design : Total power for wand: 5hr of gaming needs 812mAh Final Design Total power for wand: 5hr of gaming needs 1250mAh Current battery can sustain for 2hrs

29. Challenges: 1. wand Transmission rate between Xbees becomes slower when the end side is Raspberry Pi  Affecting the algorithm accuracy Perceptron Algorithm can only sample limited movements

30. 2. Hit Sensor Calibration time 3. User Interface Touchscreen is not stable

31. Modified Design 1. Additional Arduino in Hit Sensor Coded to enable distinguishing multiple points 2. Use Arduino Unos instead of building Arduino boards using Arduino chips Could not fix the bug of “avrdude: stk500_getsync(): not in sync: resp = 0x50”

32. Future Work Implementing the wand algorithm on a different processor to increase the complexity tolerance of calculation Integrate the processor and PCB of the wand to a lighter, smaller dimension for a better mobility Decrease hit sensor calibration time Make the touchscreen more stable Add more players to the game

33. Thank you!

34. Reference (2010) Accelerometer and Gyro Tutorial : http://www.instructables.com/id/Accelerometer-Gyro- Tutorial/ Ultrasound device data sheet : http://www.maxbotix.com/documents/MB1040_Datasheet.pdf Raspberry Pi to Arduino : http://www.cooking- hacks.com/documentation/tutorials/raspberry-pi-to- arduino- shields-connection-bridge Ultrasound receiver information: http://www.engineeringshock.com/store/p311/The_40kHz_Ultra sonic_Transducer_Receiver_DIY_Kit_w ith_Custom_PCB.html IEEE code of ethics