OV7670

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Available commercial modules:

Contents

Connecting the Elechouse module to the APF27

Description

  • OV7670 normally needs a 1,8V logic core voltage and an I/O Voltage >= 2,5V, but the modules don't care about 1,8V... Strange but it seems to work... Sensor main power supply is then taken from J9 pin 1 (2,5V)
  • Montage is straightforward, only a special cable is needed (or single wires):
  • CSI port (8 bits data + 4 bits control signals) is used to transmit images. These signals are available on the APF27Dev J9 connector (2,5V logic).
  • I2C bus (SIO) is used to configure the sensor. This 2 pins bus is available on the APF27Dev J8 connector.
APF27Dev and OV7670 module pins mapping
APF27Dev and OV7670 module pins mapping

Montage

APF27Dev with OV7670 and LCD
APF27Dev with OV7670 and LCD
OV7670 montage (I2C cable: CLK on J8 pin 8 and DATA on J8 pin 10)
OV7670 montage (I2C cable: CLK on J8 pin 8 and DATA on J8 pin 10)

Kernel config

  • Done by default on APF27
$ make linux-menuconfig
Device Drivers  --->
    Multimedia devices  --->
        [*] Video capture adapters  --->
            ...
            <M>   SoC camera support
            ...
            <M>     ov7670 camera support
            ...

Usage

# modprobe mx27_camera

Linux video capture interface: v2.00
mx27-camera mx27-camera.0: initialising
mx27-camera mx27-camera.0: Camera clock frequency: 33250006
mx27-camera mx27-camera.0: Using EMMA

# modprobe ov7670_soc

OmniVision ov7670 sensor driver, at your service
camera 0-0: Camera driver attached to camera 0
mx27-camera mx27-camera.0: mclk_get_divisor not implemented. Running at max speed
ov7670 0-0021: initializing
ov7670 0-0021: found an 0V7670 sensor
camera 0-0: Camera driver detached from camera 0

Test

# capture --cam_width 640 --cam_height 480 --width 640 --height 480 &
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