News AVR Projects

SparkFun engineers do play with what they sell. Ryan an engineer at SparkFun made use of PSP touch screen and AVR ATMega168 to construct this USB Touchscreen mouse.

The PSP touchscreen is a 4 wire analog resistive touchscreen. This means by touching the screen at one point, a resistance between each edge is formed for both the x and y axises.By applying a voltage across each axis, a changing resistance results in a changing voltage. Thus a simple ADC on a microcontroller can be used to find x and y positions. You can get more information on How USB screen works in this document here.



The ATMega168 is loaded with open source V-USB stack which turns any AVR into a USB device along with that HID profile enables it to work as a USB mouse. The only requirement is that the D+ pin needs to be connected to the INT0 pin.

More information on V-USB is available from Objective Development.


More information on this project: The AVR based USB Touchscreen Mouse