Have you ever wanted to precisely measure position with a Basic Stamp or any
microprocessor? Sure, you can roll your own solution, but it is hard to beat
the price of a common PC mouse. These mass market items often cost less than
$10, but can resolve motion in two axis at up to 800 dots per inch! Optical
mice don't even need direct contact with the surface they are measuring.
Many people have used our
popular PAK-VI chip to interface to a mouse (the
document library has several example projects with the PAK-VI). However, you
still had to decode the mouse input and decide what it meant. With the new
PAK-XI, all the work's already been done! With a simple RS-232 interface,
the PAK-XI is practically plug and play.
By default, the PAK
automatically initializes the mouse and begins recording motion. On demand,
it will send the X and Y position to the host processor along with the
current buttons state. The PAK can also latch button information so you can
detect button presses you'd otherwise miss.
With 16-bit numbers and a 400
DPI mouse, it is easy to measure distances over 80 inches on either side of
the zero point. If you prefer, you can have the host computer accumulate the
counts with more bits, which means you only need to ensure that there are
less than 80 inches per sample.
In addition, you can also set the
PAK to read the mouse in raw mode if you prefer. This is ideal for debugging or
setting special mouse modes or resolutions.
In short, the PAK-XI makes it
easy to add inexpensive, high-resolution position data to your numerically
controlled machine, robot, or any application that requires position sensing.
You can either use the mouse as-is, or remove its case and couple your device to
the sensors as needed. Either way, the PAK-XI makes it a snap to read the motion
the mouse reports.
The
Details
With the PAK-XI you receive the PAK-XI chip, a ceramic resonator, and a data
sheet that explains how to use the chip (view the datasheet
online).