Progress Presentation Final Year Project Air-Mouse for Windows/Linux PC Colin Grogan

Project Brief To design and build an air-mouse that can give accurate control over a Windows/Linux based PC. Aimed at people who may have minor movement disabilities in their hands or arms and thus cannot comfortably use a conventional mouse. To make a virtual keyboard so the user can enter text without using the physical keyboard.

Components The Toothpick will take readings from an accelerometer and 2 to 3 buttons and send the results to the PC. The PC will then decipher the results and control the mouse.

Diagram of System

Alternatives to Bluetooth Zigbee Technology Like Bluetooth, is a wireless networking standard. Used in large scale control and sensor networks e.g. Museum Security grid. More suited to be used in a system with a low data rate per connector e.g. Sensors in a Security Grid will only send data to turn on an alarm when something is wrong.

Why Bluetooth Bluetooth is more suited to a small scale project such as this. Bluetooth is used for high speed applications, battery life suffers as a result. Bluetooth is suited to this project more than Zigbee because a large amount of data will need to be sent continuously. And importantly, the Toothpick comes with full Bluetooth support.

Gesture Recognition Need to design an algorithm that will work with my device. Primary idea: When user is entering a gesture, save all points to an array. Translate array to top-left portion of screen (i.e. 0,0). Work out what shape has been drawn and compare to list of shapes. Execute command associated with found shape. Alternative idea: Assume the mouse can move in 8 directions (N, NE, E, SE, S, SW, W, NW) When mouse moves, say 10 pixels, in a certain direction, append the letter corresponding to that direction onto a string. When user is finished entering gesture, compare string with a list of strings. Execute command associated with the found string.

Milestones Pass: Design and build a working air mouse that will move the mouse in real time on the computer Average: Design and build demo and configuration software on the PC for the air mouse Good: Design a working gesture recognition algorithm for the mouse Design a application on the PC so that users can define their own gestures for later use Very Good: Get LED’s and a Webcam to detect finger positions for more input options to the PC Exceptional: Get both systems working effectively together

Progress! Currently, I am at my Pass milestone. I have the Toothpick sending data over to the Windows PC Windows driver program is moving the mouse around the screen successfully. No buttons implemented in hardware yet, easily done in software. There’s some problems though! The mouse is very jumpy around the screen, I think this is because of 2 problems. The Voltage Regulator is getting very hot so probably not giving out clean 5V. The PC software is sometimes picking up a number received from device as a negative number. The Mouse goes haywire when set to this position. Just need to change the regulator and debug the code.

Current device hardware

Design Problems The accelerometer only gives unique values between -90° and +90°. Thermal based accelerometer. Repeats itself outside of these values. Means I cant set any position for the accelerometer as the starting or ‘centre’ position. Requirement of the project was to allow mouse to be used by the persons side or resting on leg. Possible fix? Use 2-3 of the same accelerometers to get a reading at every possible position. Can be very messy to get working. Easier fix. Get an accelerometer that uses a different technology i.e. Not thermal based

Things to do Get libraries to control mouse and serial port under Linux. Write the driver software to control mouse with Linux – Should be very similar to Windows application. Gesture recognition. Write the gesture recognition application to work with the driver application.

Any Questions

References Ubuntu.iso – Images Toothpick – Windows – Ubuntu –