PixArt Imaging Inc.
ADBS-A350 Optical Finger Navigation
Bit(s)
Name
Reset
Description
Remarks
7:6
NRST_STATE
0x0
0x0: unknown
0x1: Low
Invalid as the chip will be in reset state.
Indicate a floating high
0x2: High
0x3: Hi-Z
5:4
3:2
1:0
SHUTDOWN_STATE
GPIO_STATE
0x0
0x0
0x0
0x0: unknown
0x1: Low
0x2: High
0x3: Hi-Z
Invalid as the chip will be in shutdown state.
Indicate a floating low
0x0: unknown
0x1: Low
0x2: High
0x3: Hi-Z
IO_SELECT_STATE
0x0: unknown
0x1: Low
0x2: High
0x3: Hi-Z
For output pins (EVENT_INT, GPIO, MOSI and MISO) testing,
first enable bit-4 of PAD_FUNCTION (0x34) register. Then
programorsettheoutputstateviaPAD_TEST_OUTregister
(0x33) and do a READ on the actual pin status. Actual pin
status results should match the output set in PAD_TEST_
OUT. (Note: SPI/TWI communication will be disabled after
this test is enabled. Once this test is completed, an external
hardware reset on sensor is required)
1. Sensor power up.
2. Read sensor address 0x00 for correct product ID or
PID.
3. Write sensor address 0x3a with 0x5a hex.
4. Provide a 24 MHz clock into GPIO pin at VDDIO level.
5. Write sensor address 0x28 with 0x01 hex.
6. Sensor will start to image dump with frame start for
~500 ms.
Image Dump
7. Write sensor address 0x3a with 0x5a hex to perform
soft reset or perform a hard reset to reset sensor back
to normal operation.
ADBS-A350 comes with a unique feature that enables user
to capture the image the optical sensor is seeing on the
tracking surface. This is achieved through storing the pixel
data, transferring or dumping the pixels data out to the
host for processing and rebuilding the image dump .
The rebuilding of image dump is mainly converting
each 8-bit pixel data to form a grayscale digital image.
Image Dump Setup
There are several signals which need to be tapped. They
are namely EVENT_INT, MISO_SDA and GPIO pin of the
sensor. GPIO will be input while MISO_SDA and EVENT_
INT are the output pins that the host controller must
interface to the sensor, readout the data and then build
the image dump .
Some useful applications for this feature are sensor con-
tamination inspection at manufacturing lines, image rec-
ognition, motion sensing applications and etc.
Image Dump Commands
Pin
Status
Input
Description
The host will connect to the OFN sensor and send the
following register commands to initiate image dump. The
following procedure is outlined below.
GPIO
24MHz clock signal
Pixel data bits 7 to 4
Pixel data bits 3 to 0
MISO_SDA
EVENT_INT
Output
Output
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PixArt Imaging Inc.
E-mail: fae_service@pixart.com.tw
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