Using Tilt Mouse Without Flat Surfaces

Overview

Building a mouse that could be used in any location without having a flat surface to move it on is the main concept of the project.

Explanation

Three ATmega644 microcontrollers are used by the project, which are split in two main boards consisting of transmitting and base. This handheld device uses accelerometers to detect its own orientation. It’s a feature that can be controlled by arm movements alone of a user. The two accelerometers are read by the transmitting device, which is an actual mouse, to detect motion as the data is wirelessly sent to the base board. Two ATmegas comprise the base board where they split various tasks such as TV mode, wireless receiver, and USB connectivity.

Instead of buying a dedicated hardware USB IC, the USB interface was implemented using an Atmel ATmega644 microcontroller in software. It would be cleaner and easier to implement the USB interface directly on the microcontroller based on pre-existing code rather than introduce an extra communication protocol since the wireless receiver communicates with the microcontroller through its only USART input. A custom PCB with power regulator was used to interface the ATmega644 microcontroller with external circuitry.