Trackball Module [DISCONTINUED]
NOTE: This product is currently discontinued. We leave the documentation page for reference but we no longer manufacture or sell this product.
Add a fun human interface component to your Propeller projects with the Trackball Module! Similar to the trackball found on many smart phones, this sensor is easily portable and can be used to replace a mouse in many applications. The Trackball Module comes with a built in center select switch and a red LED which can be programmed to light up the trackball when desired.
- Built-in Center select switch and red LED
- Detect movement in the up, down, left, right and diagonal directions
- 8-pin DIP module is ready for breadboard or through-hole projects
- Built-in 1 kΩ series resistors for compatibility with the Propeller microcontroller and other 3.3 V devices
- Power requirements: 5 VDC
- Communication: Four-pin variable-frequency binary signaling output (for trackball)
- Dimensions: 1.0 x 1.0 x 0.67 in (25.4 x 25.4 x 17.08 mm)
- Operating temp range: +32 to +158°F (0 to +70°C)
- Mouse replacement
- Video game input
Theory of Operation
The Trackball Module has four tiny rotatable magnets attached to each corner of the component. Rotating the Trackball Module in the up, down, left, or right directions will result in the rotation of one magnet, while any diagonal movement will result in the rotation of two magnets.
Whenever any of the magnets rotate, a tiny magnetic field is created, which can be detected by a Hall Effect sensor paired with each magnet. The Hall Effect sensor will then output a series of high/low signals which can be monitored by the Propeller microcontroller to determine the direction of movement of the trackball. The speed of rotation is then proportional to the period of the pulse, where slow rotation will result in a longer period and faster rotation will result in a shorter period.
Note: The Trackball Module does require a small break-in period before the ball will rotate smoothly.
Pin Definitions and Ratings
|1||+5V||5V Supply Voltage|
|2||OPA||Output of Hall Effect IC - Up|
|3||SW||Center select switch, active-high|
|4||OPB||Output of Hall Effect IC - Left|
|5||GND||Ground -> 0V|
|6||OPC||Output of Hall Effect IC - Down|
|7||LED||LED control pin|
|8||OPD||Output of Hall Effect IC - Right|
Propeller™ P8X32A Application
The Trackball Module Demo uses the Parallax Serial Terminal to display the current movement of the Trackball Module. The Parallax Serial Terminal itself is installed with the Propeller Tool v1.2.7 which is available in the link below