May
2006, Issue 190
Image
Processing for Robots
Renesas
M16C Platform Design Contest 2005
SENSOR
& MCU
Figure
2 shows how the M30624 microcontroller is connected
to the image sensor. The interface to the picture sensor
is digital. An 8-bit data bus sends picture data. The
PCLK and VSYNC signals synchronize the data transmission.
The VSYNC signal goes high at the beginning of every
image frame. Rising edges on the PCLK signal identify
valid pixel data.
An
I2C bus controls the OV6620’s internal registers. For
better mechanical adaptation, a separate PCB holds the
connectors for the picture sensor and the flat cable
to the main board. The image sensor board connects via
X1.
The
74HC00 inverts the polarity of the PCLK signal. Two
pull-up resistors (RX2 and RX3) are necessary for the
I2C bus. The bus signals are labeled SCCB_DATA and SCCB_CLK.
The HSYNC is unused. The RESET signal resets the image
sensor if necessary. You can use the PWDN signal to
minimize power consumption.
|
(Click
here to enlarge)
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Figure
2—The connection between the CMOS camera and Renesas
M30624 microcontroller is a simple one. There are
only digital signals. Pixel data is captured by
the M30624’s port P3. A serial bus controls the
sensor’s internal registers. A DMA channel transfers
data directly into the microcontroller’s RAM space.
This saves time and computational power. |
