A weblog focused on interesting circuits, ideas, schematics and other information about microelectronics and microcontrollers.
Positional Sensor Interface
Low cost and easily implemented sensors for homebrew robotics projects.
This project implements and demonstrates an interface which supports up to 3 moderately precise non-contact XY sensors, 3 low resolution rotational sensors, and 9 switches using a simple protocol on a single communications channel. The project uses the ATmega16 and the STK500 AVR Starter Kit. The sensors which the interface controls are components in one to three inexpensive (under $10 each) optical scroll mice. Each mouse has 3 switches, a scroll wheel, and an optical XY sensor.
To demonstrate some of the features of the interface, two devices have been cobbled together along with some simple PC host software. These demonstrations, while possibly short on practicality, should give a flavor of the types of uses the interface may find.
The MouseMobile demonstates two mice in fairly conventional use. Built in the guise of a car, its host software displays a graphic trace of its position as it moves and rotates. Acting as a digitizer and distance measurer, it can also locate the midpoint of an arbitrarily drawn curve.
The Mousitizer is a polar coordinate digitizer and demonstrates how the interface can use an XY sensor to detect rotational motion and the rotational sensor to detect linear motion.