ADNK-3043-TI27 Avago Technologies US Inc., ADNK-3043-TI27 Datasheet - Page 3

• Manufacturer Part Number: ADNK-3043-TI27
• Description: WIRELESS MOUSE DESIGN KIT
• Manufacturer: Avago Technologies US Inc.
• Type: Wireless Mouse Development Kitr

Specifications of ADNK-3043-TI27

• Frequency: 2.4GHz
• Description/function: Optical Mouse Sensor Kit
• Interface Type: USB
• Product: Display Modules
• Touch Panel: No Touch Panel
• For Use With/related Products: ADNS-3043
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

Z Wheel
The motion of Z-wheel is detected using the quadrature
signal generated by optical sensors. Two phototransistors
are connected in a source-follower configuration forming
Channel A and Channel B . An infrared LED shines, causing
the phototransistors to turn on. In between the phototran-
sistors and the LED is a pinwheel that rotates. The spokes
of this pinwheel is mechanically designed to interrupt the
infrared light such that the phototransistors are turned on
and off in a quadrature output pattern. Every change in
the phototransistor outputs represents a count of Z-wheel
movement. Comparing the last state of the optics to the
current state derives directional information. As shown
in Figure 3 below, rotating the wheel forward produces
a unique set of state transitions, and rotating the wheel
backward produces another set of unique state transi-
tions.
Figure 3. Optics Quadrature Signal Generation
Mouse Buttons
Mouse buttons are connected as standard switches. These
switches are pulled up by the pull up resistors inside the
microcontroller. When the user presses a button, the switch
will be closed and the pin will be pulled LOW to GND. A
LOW state at the pin is interpreted as the button being
pressed. A HIGH state is interpreted as the button has been
released or the button is not being pressed. Normally the
switches are debounced in firmware for 15-20ms. In this
reference design there are three switches: left, Z-wheel,
and right.
3
Hardware Implementation
Optical Mouse Sensor
This reference design features the ADNS-3040 optical
navigation engine. It contains an Image Acquisition System
(IAS), a Digital Signal Processor (DSP), and a four-wire Serial
Peripheral Interface consists of the serial clock (SCLK), the
master-in/slave-out (MISO) and the master-out/slave-in
(MOSI). In addition a fourth signal chip select (NCS) is used
to select the device on the SPI buss. Motion, is an addi-
tional output from the ADNS-3040 intended to act as an
interrupt to the microcontroller whenever the ADNS-3040
senses motion. When the mouse is moved the ADNS-3040
alerts the system controller by activating the Motion signal
triggering an interrupt service routine. At the same time
the ADNS-3040 accumulates the horizontal and vertical
displacements (count per inch, or cpi) in its Delta_X and
Delta_Y registers respectively. The ADNS-3040 deactivates
the Motion signal as soon as movement stops. The Smart-
Speed technology automatically optimizes the frame rate
by examining the acquired images of the surface. It also
manages the integrated LED driver to coordinate with the
shutter.
The system controller reads the motion information and
reports it to the PC to update the cursor position.
The advantages of using ADNS-3040 optical sensor are the
efficient power management, high tracking accuracy, and
simple communications with the microcontroller via the
full duplex SPI port.
To learn more about sensor’s technical information, please visit the
Avago web site at http://www.avagotech.com