Final Report. Project Name: Magic Glove

Transcription

1 EEL 4924 Electrical Engineering Design (Senior Design) Final Report 20 April 2011 Project Name: Magic Glove Team Members: Name: Alan Hess Name: Gianni Gibelli Project Abstract: The wireless Magic Glove project aims to take the place of the traditional, easily misplaced remote control for a Scientific Atlanta Explorer 3250HD cable box. The glove acts as the input mechanism to a system which recognizes a variety of hand gestures and translates them into infrared signals for the cable box to recognize, at the receiver end. Embedded into the layers of the glove will be flex sensors for three fingers and an accelerometer. The transmitter microcontroller and circuitry is intended to be ergonomic so that it is virtually unnoticeable to the user. Its low-power design makes it comparable in battery life to its remote control counterpart. The project implements simple commands like "Volume Up/Down", "Channel Up/Down", and "Power. The glove also implements more complex commands like "Guide", "Up/Down/Left/Right" within the guide, "Exit" and the ability to recognize up to 3 invisibly drawn digits to select a specific channel.

2 Page 2/10 Table of Contents Project Abstract...1 Project Features...3 Analysis of Competition...3 Components...4 Technical Objectives...5 Project Architecture...5 Software Flowchart...6 Schematics and Layouts...7 Distribution of Labor...9 Bill of Materials...9 Gantt Chart...10 References List of Tables Table 1: Distribution of Labor...9 Table 2: Bill of Materials...9 List of Figures Figure 1: Block Diagram...5 Figure 2: Transmitter and Receiver Flowcharts...6 Figure 3: Receiver Schematic...7 Figure 4: Receiver PCB Design...7 Figure 5: Transmitter Schematic...8 Figure 6: Transmitter PCB Design...8 Figure 7: Project Timeline...10

3 Page 3/10 Project Features The Magic Glove attempts to solve the problem of the commonly misplaced television remote, while at the same time re-inventing the way we interact with multimedia centers. This version of the Magic Glove is a prototype showing the possibilities of a remote control glove in the application of controlling a Scientific Atlanta Explorer 3250HD cable box. This cable box was used for its significance for the general population in the area and for its larger array of commands to use. Implementing flex sensors and an ergonomic glove solution, the Magic Glove is able to send specific commands to a receiving station for decoding. The receiver is responsible for decoding the signal sent by the glove and generating the appropriate infrared signal for the cable box to understand. By combining the inputs from three flex sensors and an accelerometer, we can implement up to 6 command menus using the flex sensors with limitless specific commands by drawing in the air using the accelerometer. For the purpose of this project, we implement a total of 22 commands. The final device is a comfortable, innovative remote control that replaces a bulkier, easily misplaced remote control involving buttons, with sometimes confusing layouts. Features include: Commands made using flex sensors and an accelerometer to maximize user inputs. A transmitter that fits comfortably on the back of a medium sized glove. A transmitter/receiver combination consisting of two low-power MSP430 microcontrollers paired with XBees. The capability to detect volume, channel, guide, and number gestures efficiently. A wireless setup that allows for directional freedom while inputting commands. A feedback LED on the transmitter and a feedback LCD screen on the receiver. Analysis of Competition A variety of home-made glove projects have been designed, but no similar designs have been sold. Other glove concepts are designed as a computer mouse, use LEDs in order to recognize movement, or use an accelerometer or the flex sensors separately or for other purposes. Our glove recognizes gestures using only an accelerometer and flex sensors, and with a stand-alone transmitter/receiver combination. A gesture recognition system was designed by Carnegie Melon students using a Wii-Mote that involves dynamic time warping in order to recognize more detailed gestures. Our project strictly uses left, right, up and down movements as a basis for gestures. Another project was developed at Georgia Tech that used a glove as sign-language game which requires a camera to track movement aside from an accelerometer/gyroscope combination on a glove. A Microsoft invention group has patented a "magic wand" concept similar to ours using only an accelerometer.

4 Page 4/10 Components MSP430F2272 TI Microcontroller [1] The MSP430 was chosen for its versatility and robustness. The MSP430 offers low-power consumption in a small package. Although it does not offer floating-point precision for more complex signal processing algorithms such as Dynamic Time Warping and the Hidden Markov Model, the MSP supports enough processing power for our straight-line approach. Lastly, the MSP430F2272 has enough ports to support an SPI accelerometer, 3 ADC ports for the flex sensors, a UART interface for the XBees, and room for other LED's and peripherals. Triple Axis Accelerometer Breakout - LIS3LV02DQ sku: SEN The LIS3LV02DQ is a triple-axis accelerometer which communicates via SPI or I2C digital output. The LIS3LV02DQ is unique in that it contains an internal high-pass filter which offsets the accelerometer readings due to gravity. This is important because otherwise the accelerometer would also detect tilt when we are really interested in directional displacements. The LIS3LV02DQ is capable of working with 2g or 6g of resolution and when running in SPI it is fast enough to do real-time gesture recognition (640hz) given efficient programming. This specific accelerometer has presently been discontinued. It is important for future applications to find an accelerometer that includes a high-pass filter. Flex Sensor 2.2" sku: SEN The Sparkfun [2] 2.2" flex sensors are ideal for the magic glove because they fit right along the fingers of the glove. These flex sensors are acclaimed to be the same as those used in the original Nintendo Power Glove and are rated for over 1 million flexes. The mechanism of the flex sensors is such that the resistance of the flex sensor changes proportionally to the bend, like a potentiometer. When placed along the fingers, the bending of the knuckles at the middle of the sensor is fully detectable and generates a useful signal to work with. XBee 1mW Chip Antenna sku: WRL The XBee module uses the protocol stack to transmit serially at 2.4GHz. The XBee offers a reliable communication line in a point-to-point or multi-point fashion. The XBee is ideal for sending quick packets of data for command execution in real-time.

5 Page 5/10 Technical Objectives The main objective of our project is to design a remote control glove that can intuitively control any IR controlled device using unique hand gestures. The transmitter is designed to fit on the back of a medium-sized glove. The transmitter/receiver combination consists of two low-power MSP430 microcontrollers. The receiver simply runs an IR LED and is powered from the wall. The transmitter is battery-powered and only consumes power when in use for detecting hand signals and transmitting the information to the receiver. The glove can be turned off by a simple switch when not being used. Different commands to the cable box are made using a combination of inputs from separate flex sensors along each finger of the glove and an accelerometer on the glove. These inputs will be recognized by one MSP430 through an ADC and transmitted to another MSP430 near the cable box to be decoded as an IR signal. Project Architecture The components mentioned above are arranged as follows to best serve their purpose: Figure 1: Block Diagram

6 Page 6/10 Software Flowchart Figure 2: Transmitter and Receiver Flowcharts

7 Page 7/10 Schematics and Layouts Figure 3: Receiver Schematic Figure 4: Receiver PCB Design

8 Page 8/10 Figure 5: Transmitter Schematic Figure 6: Transmitter PCB Design

9 Page 9/10 Distribution of Labor The following is a breakdown of the expected percentage of work from each team member. Alan Hess (%) Gianni Gibelli (%) Research IR encoding RF transmission Hardware design Programming Prototyping Bill of Materials Table 1: Distribution of Labor The following bill of materials is our final list of components and their cost. Component Cost Per Unit ($US) # of Units Total ($US) XBee 1mW Chip Antenna sku: WRL Flex Sensor 2.2" sku: SEN Triple Axis Accelerometer Breakout - LIS3LV02DQ sku: SEN Advanced Circuit Transmitter PCB Board [3] MSP430F TI Microcontroller Nike Baseball Glove AAA Batteries Miscellaneous Parts Total Table 2: Bill of Materials

10 Page 10/10 Gantt Chart This is the timeline we adhered to with a slight change in the final stages where got a month ahead of schedule thanks to hardware debugging in parallel with ALTIUM design before spring break. References Figure 7: Project Timeline [1] Texas Instruments Texas Instruments. April 6, < [2] Sparkfun Electronics. April 6, Sparkfun Electronics. April 6, < [3] Advanced Circuits Advanced Circuits. April 6, < [4] G. Dixon. "Specification of IRP Notation." February 4, JP1 Remotes. April 18, < [5] "Interpreting Decoded IR Signals." HiFi-Remote. April 18, <