How to Use OV7670 Camera by Arduino Uno ?

Arduino UNO 05-11-24

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Tutorial plan

1- Definition of OV7670 Camera

2- Components Needed to command OV7670 Camera by Arduino

3- Circuit Setup

4- Programming the Arduino

Definition of OV7670 Camera

The OV7670 is a low-cost, low-power CMOS image sensor and camera module, commonly used for capturing images and videos in embedded systems and microcontroller projects. Developed by OmniVision, this module is known for its compact design and is often paired with microcontrollers like Arduino and ESP32 for basic image processing tasks.

Key Features of the OV7670 Camera:

Resolution: Provides a maximum resolution of 640x480 pixels (VGA) and can also operate at lower resolutions like 320x240 (QVGA).

Interface: Communicates with a microcontroller via an 8-bit parallel output or a serial camera control bus (SCCB).

Frame Rate: Can capture images at frame rates up to 30 frames per second.

Adjustable Settings: Has settings for brightness, contrast, saturation, white balance, and other image qualities.

Applications: Often used for applications in surveillance, object tracking, basic computer vision tasks, and educational projects.

OV7670 Limitations:

The OV7670 lacks onboard image processing power, meaning it relies on the microcontroller or microprocessor to handle most processing tasks, which can be challenging for high-resolution or high-speed applications. Additionally, it does not have onboard memory, so captured data must be processed or stored quickly.

Components Needed to command OV7670 Camera by Arduino

To connect and control an OV7670 camera module with an Arduino board, you’ll need the following components:

Components Needed

Arduino UNO:

Arduino Uno

The main microcontroller that will interface with the OV7670. The Uno has limited memory, which restricts image capture resolution and processing capabilities.

OV7670 Camera Module:

The CMOS camera module that will capture the images.

2 resistors of 4.7 kΩ :

2 resistors of 10 kΩ

Connecting Wires:

Jumper wires

Jumper wires to connect the buzzer to the ESP32's pins.

Breadboard (Optional):

Breadboard

Useful for setting up a prototype.

3.3V/5V power module

A 3.3V/5V power module is a small, low-cost device designed to convert an input voltage (typically 5V or higher) into stable 3.3V and 5V outputs, making it very useful for powering various electronics and sensors that require either of these voltages. This module is often used in embedded projects with microcontrollers, sensors, and modules that require different power levels, such as the Arduino, ESP32, and camera modules like the OV7670.

Circuit Setup

Here are the steps to assemble the OV7670 camera module and Arduino Uno board:

1- First, connect the power supply pins (VCC and GND) of the OV7670 camera module to the 3.3V and GND pins of the Arduino Uno board, respectively.

2- Next, connect the data pins of the OV7670 camera module to the Arduino Uno board. The SCCB (Serial Camera Control Bus) pins of the OV7670 camera module should be connected to the analog input pins (A4 and A5) of the Arduino Uno board. The camera data pins (D0 to D7) should be connected to the digital pins of the Arduino Uno board as follows:

D0 -> A0

D1 -> A1

D2 -> A2

D3 -> A3

D4 -> D4

D5 -> D5

D6 -> D6

D7 -> D7

3- Connect the synchronization signals of the OV7670 camera module to the digital pins of the Arduino Uno board. The HREF (Horizontal Reference) signal should be connected to digital pin D8, while the VSYNC (Vertical Synchronization) signal should be connected to digital pin D7. The PCLK (Pixel Clock) signal should be connected to digital pin D6.

4- Once all the connections are made, you can upload the code to the Arduino Uno board to interface with the OV7670 camera module. You can use the OV7670 Arduino library to interface with the camera module and capture images or video.

5- To test the assembly, you can use the Arduino serial monitor to display the captured images or video data.

Note: The OV7670 camera module requires a lot of processing power and memory, so you might need to use a faster board like Arduino Mega or a separate microcontroller along with Arduino Uno for image processing.

Programming the Arduino

Here is an example of a basic Arduino program that captures real-time images from the OV7670 camera and displays them on the OV7670 window

Once connected, you’ll need a library to interact with the OV7670, although options are limited. Due to the Arduino’s memory constraints, capturing and displaying full-frame images is challenging. Projects typically involve capturing lower-resolution grayscale images or using external storage.

The following code snippet initializes the camera but may need customization based on your Arduino model and the specific application:

//
// Source code for application to transmit image from ov7670 to PC via USB
// By Siarhei Charkes in 2015
// http://privateblog.info 
//

#include <stdint.h>
#include <avr/io.h>
#include <util/twi.h>
#include <util/delay.h>
#include <avr/pgmspace.h>

#define F_CPU 16000000UL
#define vga   0
#define qvga  1
#define qqvga   2
#define yuv422  0
#define rgb565  1
#define bayerRGB  2
#define camAddr_WR  0x42
#define camAddr_RD  0x43

/* Registers */
#define REG_GAIN    0x00  /* Gain lower 8 bits (rest in vref) */
#define REG_BLUE    0x01  /* blue gain */
#define REG_RED       0x02  /* red gain */
#define REG_VREF    0x03  /* Pieces of GAIN, VSTART, VSTOP */
#define REG_COM1    0x04  /* Control 1 */
#define COM1_CCIR656  0x40    /* CCIR656 enable */

#define REG_BAVE    0x05  /* U/B Average level */
#define REG_GbAVE   0x06  /* Y/Gb Average level */
#define REG_AECHH   0x07  /* AEC MS 5 bits */
#define REG_RAVE    0x08  /* V/R Average level */
#define REG_COM2    0x09  /* Control 2 */
#define COM2_SSLEEP         0x10  /* Soft sleep mode */
#define REG_PID           0x0a  /* Product ID MSB */
#define REG_VER           0x0b  /* Product ID LSB */
#define REG_COM3    0x0c  /* Control 3 */
#define COM3_SWAP         0x40  /* Byte swap */
#define COM3_SCALEEN          0x08  /* Enable scaling */
#define COM3_DCWEN          0x04  /* Enable downsamp/crop/window */
#define REG_COM4    0x0d  /* Control 4 */
#define REG_COM5    0x0e  /* All "reserved" */
#define REG_COM6    0x0f  /* Control 6 */
#define REG_AECH    0x10  /* More bits of AEC value */
#define REG_CLKRC   0x11  /* Clocl control */
#define CLK_EXT           0x40  /* Use external clock directly */
#define CLK_SCALE   0x3f  /* Mask for internal clock scale */
#define REG_COM7    0x12  /* Control 7 */ //REG mean address.
#define COM7_RESET          0x80  /* Register reset */
#define COM7_FMT_MASK         0x38
#define COM7_FMT_VGA          0x00
#define COM7_FMT_CIF          0x20  /* CIF format */
#define COM7_FMT_QVGA         0x10  /* QVGA format */
#define COM7_FMT_QCIF         0x08  /* QCIF format */
#define COM7_RGB          0x04  /* bits 0 and 2 - RGB format */
#define COM7_YUV          0x00  /* YUV */
#define COM7_BAYER          0x01  /* Bayer format */
#define COM7_PBAYER         0x05  /* "Processed bayer" */
#define REG_COM8    0x13  /* Control 8 */
#define COM8_FASTAEC          0x80  /* Enable fast AGC/AEC */
#define COM8_AECSTEP          0x40  /* Unlimited AEC step size */
#define COM8_BFILT    0x20  /* Band filter enable */
#define COM8_AGC    0x04  /* Auto gain enable */
#define COM8_AWB    0x02  /* White balance enable */
#define COM8_AEC    0x01  /* Auto exposure enable */
#define REG_COM9    0x14  /* Control 9- gain ceiling */
#define REG_COM10   0x15  /* Control 10 */
#define COM10_HSYNC         0x40  /* HSYNC instead of HREF */
#define COM10_PCLK_HB         0x20  /* Suppress PCLK on horiz blank */
#define COM10_HREF_REV          0x08  /* Reverse HREF */
#define COM10_VS_LEAD         0x04  /* VSYNC on clock leading edge */
#define COM10_VS_NEG          0x02  /* VSYNC negative */
#define COM10_HS_NEG          0x01  /* HSYNC negative */
#define REG_HSTART    0x17  /* Horiz start high bits */
#define REG_HSTOP   0x18  /* Horiz stop high bits */
#define REG_VSTART    0x19  /* Vert start high bits */
#define REG_VSTOP   0x1a  /* Vert stop high bits */
#define REG_PSHFT   0x1b  /* Pixel delay after HREF */
#define REG_MIDH    0x1c  /* Manuf. ID high */
#define REG_MIDL    0x1d  /* Manuf. ID low */
#define REG_MVFP    0x1e  /* Mirror / vflip */
#define MVFP_MIRROR         0x20  /* Mirror image */
#define MVFP_FLIP   0x10  /* Vertical flip */

#define REG_AEW           0x24  /* AGC upper limit */
#define REG_AEB           0x25    /* AGC lower limit */
#define REG_VPT           0x26  /* AGC/AEC fast mode op region */
#define REG_HSYST   0x30  /* HSYNC rising edge delay */
#define REG_HSYEN   0x31  /* HSYNC falling edge delay */
#define REG_HREF    0x32  /* HREF pieces */
#define REG_TSLB    0x3a  /* lots of stuff */
#define TSLB_YLAST    0x04  /* UYVY or VYUY - see com13 */
#define REG_COM11   0x3b  /* Control 11 */
#define COM11_NIGHT         0x80  /* NIght mode enable */
#define COM11_NMFR          0x60  /* Two bit NM frame rate */
#define COM11_HZAUTO          0x10  /* Auto detect 50/60 Hz */
#define COM11_50HZ          0x08  /* Manual 50Hz select */
#define COM11_EXP   0x02
#define REG_COM12   0x3c  /* Control 12 */
#define COM12_HREF          0x80  /* HREF always */
#define REG_COM13   0x3d  /* Control 13 */
#define COM13_GAMMA         0x80  /* Gamma enable */
#define COM13_UVSAT         0x40  /* UV saturation auto adjustment */
#define COM13_UVSWAP          0x01  /* V before U - w/TSLB */
#define REG_COM14   0x3e  /* Control 14 */
#define COM14_DCWEN         0x10  /* DCW/PCLK-scale enable */
#define REG_EDGE    0x3f  /* Edge enhancement factor */
#define REG_COM15   0x40  /* Control 15 */
#define COM15_R10F0         0x00  /* Data range 10 to F0 */
#define COM15_R01FE         0x80  /*      01 to FE */
#define COM15_R00FF         0xc0  /*      00 to FF */
#define COM15_RGB565          0x10  /* RGB565 output */
#define COM15_RGB555          0x30  /* RGB555 output */
#define REG_COM16   0x41  /* Control 16 */
#define COM16_AWBGAIN         0x08  /* AWB gain enable */
#define REG_COM17   0x42  /* Control 17 */
#define COM17_AECWIN          0xc0  /* AEC window - must match COM4 */
#define COM17_CBAR          0x08  /* DSP Color bar */
/*
* This matrix defines how the colors are generated, must be
* tweaked to adjust hue and saturation.
*
* Order: v-red, v-green, v-blue, u-red, u-green, u-blue
* They are nine-bit signed quantities, with the sign bit
* stored in0x58.Sign for v-red is bit 0, and up from there.
*/
#define REG_CMATRIX_BASE  0x4f
#define CMATRIX_LEN           6
#define REG_CMATRIX_SIGN  0x58
#define REG_BRIGHT    0x55  /* Brightness */
#define REG_CONTRAS         0x56  /* Contrast control */
#define REG_GFIX    0x69  /* Fix gain control */
#define REG_REG76   0x76  /* OV's name */
#define R76_BLKPCOR         0x80  /* Black pixel correction enable */
#define R76_WHTPCOR         0x40  /* White pixel correction enable */
#define REG_RGB444          0x8c  /* RGB 444 control */
#define R444_ENABLE         0x02  /* Turn on RGB444, overrides 5x5 */
#define R444_RGBX   0x01  /* Empty nibble at end */
#define REG_HAECC1    0x9f  /* Hist AEC/AGC control 1 */
#define REG_HAECC2    0xa0  /* Hist AEC/AGC control 2 */
#define REG_BD50MAX         0xa5  /* 50hz banding step limit */
#define REG_HAECC3    0xa6  /* Hist AEC/AGC control 3 */
#define REG_HAECC4    0xa7  /* Hist AEC/AGC control 4 */
#define REG_HAECC5    0xa8  /* Hist AEC/AGC control 5 */
#define REG_HAECC6    0xa9  /* Hist AEC/AGC control 6 */
#define REG_HAECC7    0xaa  /* Hist AEC/AGC control 7 */
#define REG_BD60MAX         0xab  /* 60hz banding step limit */
#define REG_GAIN    0x00  /* Gain lower 8 bits (rest in vref) */
#define REG_BLUE    0x01  /* blue gain */
#define REG_RED           0x02  /* red gain */
#define REG_VREF    0x03  /* Pieces of GAIN, VSTART, VSTOP */
#define REG_COM1    0x04  /* Control 1 */
#define COM1_CCIR656          0x40  /* CCIR656 enable */
#define REG_BAVE    0x05  /* U/B Average level */
#define REG_GbAVE   0x06  /* Y/Gb Average level */
#define REG_AECHH   0x07  /* AEC MS 5 bits */
#define REG_RAVE    0x08  /* V/R Average level */
#define REG_COM2    0x09  /* Control 2 */
#define COM2_SSLEEP         0x10  /* Soft sleep mode */
#define REG_PID           0x0a  /* Product ID MSB */
#define REG_VER           0x0b  /* Product ID LSB */
#define REG_COM3    0x0c  /* Control 3 */
#define COM3_SWAP         0x40  /* Byte swap */
#define COM3_SCALEEN          0x08  /* Enable scaling */
#define COM3_DCWEN          0x04  /* Enable downsamp/crop/window */
#define REG_COM4    0x0d  /* Control 4 */
#define REG_COM5    0x0e  /* All "reserved" */
#define REG_COM6    0x0f  /* Control 6 */
#define REG_AECH    0x10  /* More bits of AEC value */
#define REG_CLKRC   0x11  /* Clocl control */
#define CLK_EXT           0x40  /* Use external clock directly */
#define CLK_SCALE   0x3f  /* Mask for internal clock scale */
#define REG_COM7    0x12  /* Control 7 */
#define COM7_RESET          0x80  /* Register reset */
#define COM7_FMT_MASK         0x38
#define COM7_FMT_VGA          0x00
#define COM7_FMT_CIF          0x20  /* CIF format */
#define COM7_FMT_QVGA         0x10  /* QVGA format */
#define COM7_FMT_QCIF         0x08  /* QCIF format */
#define COM7_RGB    0x04  /* bits 0 and 2 - RGB format */
#define COM7_YUV    0x00  /* YUV */
#define COM7_BAYER          0x01  /* Bayer format */
#define COM7_PBAYER         0x05  /* "Processed bayer" */
#define REG_COM8    0x13  /* Control 8 */
#define COM8_FASTAEC          0x80  /* Enable fast AGC/AEC */
#define COM8_AECSTEP          0x40  /* Unlimited AEC step size */
#define COM8_BFILT    0x20  /* Band filter enable */
#define COM8_AGC    0x04  /* Auto gain enable */
#define COM8_AWB    0x02  /* White balance enable */
#define COM8_AEC    0x01  /* Auto exposure enable */
#define REG_COM9    0x14  /* Control 9- gain ceiling */
#define REG_COM10   0x15  /* Control 10 */
#define COM10_HSYNC         0x40  /* HSYNC instead of HREF */
#define COM10_PCLK_HB         0x20  /* Suppress PCLK on horiz blank */
#define COM10_HREF_REV          0x08  /* Reverse HREF */
#define COM10_VS_LEAD           0x04  /* VSYNC on clock leading edge */
#define COM10_VS_NEG          0x02  /* VSYNC negative */
#define COM10_HS_NEG          0x01  /* HSYNC negative */
#define REG_HSTART    0x17  /* Horiz start high bits */
#define REG_HSTOP   0x18  /* Horiz stop high bits */
#define REG_VSTART    0x19  /* Vert start high bits */
#define REG_VSTOP   0x1a  /* Vert stop high bits */
#define REG_PSHFT   0x1b  /* Pixel delay after HREF */
#define REG_MIDH    0x1c  /* Manuf. ID high */
#define REG_MIDL    0x1d  /* Manuf. ID low */
#define REG_MVFP    0x1e  /* Mirror / vflip */
#define MVFP_MIRROR         0x20  /* Mirror image */
#define MVFP_FLIP   0x10  /* Vertical flip */
#define REG_AEW           0x24  /* AGC upper limit */
#define REG_AEB           0x25  /* AGC lower limit */
#define REG_VPT           0x26  /* AGC/AEC fast mode op region */
#define REG_HSYST   0x30  /* HSYNC rising edge delay */
#define REG_HSYEN   0x31  /* HSYNC falling edge delay */
#define REG_HREF    0x32  /* HREF pieces */
#define REG_TSLB    0x3a  /* lots of stuff */
#define TSLB_YLAST    0x04  /* UYVY or VYUY - see com13 */
#define REG_COM11   0x3b  /* Control 11 */
#define COM11_NIGHT         0x80  /* NIght mode enable */
#define COM11_NMFR          0x60  /* Two bit NM frame rate */
#define COM11_HZAUTO          0x10  /* Auto detect 50/60 Hz */
#define COM11_50HZ          0x08  /* Manual 50Hz select */
#define COM11_EXP   0x02
#define REG_COM12   0x3c  /* Control 12 */
#define COM12_HREF          0x80  /* HREF always */
#define REG_COM13   0x3d  /* Control 13 */
#define COM13_GAMMA         0x80  /* Gamma enable */
#define COM13_UVSAT         0x40  /* UV saturation auto adjustment */
#define COM13_UVSWAP          0x01  /* V before U - w/TSLB */
#define REG_COM14   0x3e  /* Control 14 */
#define COM14_DCWEN         0x10  /* DCW/PCLK-scale enable */
#define REG_EDGE    0x3f  /* Edge enhancement factor */
#define REG_COM15   0x40  /* Control 15 */
#define COM15_R10F0         0x00  /* Data range 10 to F0 */
#define COM15_R01FE         0x80  /*      01 to FE */
#define COM15_R00FF         0xc0  /*      00 to FF */
#define COM15_RGB565          0x10  /* RGB565 output */
#define COM15_RGB555          0x30  /* RGB555 output */
#define REG_COM16   0x41  /* Control 16 */
#define COM16_AWBGAIN         0x08  /* AWB gain enable */
#define REG_COM17   0x42  /* Control 17 */
#define COM17_AECWIN          0xc0  /* AEC window - must match COM4 */
#define COM17_CBAR          0x08  /* DSP Color bar */

#define CMATRIX_LEN             6
#define REG_BRIGHT    0x55  /* Brightness */
#define REG_REG76   0x76  /* OV's name */
#define R76_BLKPCOR         0x80  /* Black pixel correction enable */
#define R76_WHTPCOR         0x40  /* White pixel correction enable */
#define REG_RGB444          0x8c  /* RGB 444 control */
#define R444_ENABLE         0x02  /* Turn on RGB444, overrides 5x5 */
#define R444_RGBX   0x01  /* Empty nibble at end */
#define REG_HAECC1    0x9f  /* Hist AEC/AGC control 1 */
#define REG_HAECC2    0xa0  /* Hist AEC/AGC control 2 */
#define REG_BD50MAX         0xa5  /* 50hz banding step limit */
#define REG_HAECC3    0xa6  /* Hist AEC/AGC control 3 */
#define REG_HAECC4    0xa7  /* Hist AEC/AGC control 4 */
#define REG_HAECC5    0xa8  /* Hist AEC/AGC control 5 */
#define REG_HAECC6    0xa9  /* Hist AEC/AGC control 6 */
#define REG_HAECC7    0xaa  /* Hist AEC/AGC control 7 */
#define REG_BD60MAX         0xab  /* 60hz banding step limit */
#define MTX1            0x4f  /* Matrix Coefficient 1 */
#define MTX2            0x50  /* Matrix Coefficient 2 */
#define MTX3            0x51  /* Matrix Coefficient 3 */
#define MTX4            0x52  /* Matrix Coefficient 4 */
#define MTX5            0x53  /* Matrix Coefficient 5 */
#define MTX6            0x54  /* Matrix Coefficient 6 */
#define REG_CONTRAS         0x56  /* Contrast control */
#define MTXS            0x58  /* Matrix Coefficient Sign */
#define AWBC7           0x59  /* AWB Control 7 */
#define AWBC8           0x5a  /* AWB Control 8 */
#define AWBC9           0x5b  /* AWB Control 9 */
#define AWBC10            0x5c  /* AWB Control 10 */
#define AWBC11            0x5d  /* AWB Control 11 */
#define AWBC12            0x5e  /* AWB Control 12 */
#define REG_GFI           0x69  /* Fix gain control */
#define GGAIN           0x6a  /* G Channel AWB Gain */
#define DBLV            0x6b  
#define AWBCTR3           0x6c  /* AWB Control 3 */
#define AWBCTR2           0x6d  /* AWB Control 2 */
#define AWBCTR1           0x6e  /* AWB Control 1 */
#define AWBCTR0           0x6f  /* AWB Control 0 */

struct regval_list{
  uint8_t reg_num;
  uint16_t value;
};

const struct regval_list qvga_ov7670[] PROGMEM = {
  { REG_COM14, 0x19 },
  { 0x72, 0x11 },
  { 0x73, 0xf1 },

  { REG_HSTART, 0x16 },
  { REG_HSTOP, 0x04 },
  { REG_HREF, 0xa4 },
  { REG_VSTART, 0x02 },
  { REG_VSTOP, 0x7a },
  { REG_VREF, 0x0a },

/*  { REG_HSTART, 0x16 },
  { REG_HSTOP, 0x04 },
  { REG_HREF, 0x24 },
  { REG_VSTART, 0x02 },
  { REG_VSTOP, 0x7a },
  { REG_VREF, 0x0a },*/
  { 0xff, 0xff }, /* END MARKER */
};

const struct regval_list yuv422_ov7670[] PROGMEM = {
  { REG_COM7, 0x0 },  /* Selects YUV mode */
  { REG_RGB444, 0 },  /* No RGB444 please */
  { REG_COM1, 0 },
  { REG_COM15, COM15_R00FF },
  { REG_COM9, 0x6A }, /* 128x gain ceiling; 0x8 is reserved bit */
  { 0x4f, 0x80 },   /* "matrix coefficient 1" */
  { 0x50, 0x80 },   /* "matrix coefficient 2" */
  { 0x51, 0 },    /* vb */
  { 0x52, 0x22 },   /* "matrix coefficient 4" */
  { 0x53, 0x5e },   /* "matrix coefficient 5" */
  { 0x54, 0x80 },   /* "matrix coefficient 6" */
  { REG_COM13, COM13_UVSAT },
  { 0xff, 0xff },   /* END MARKER */
};

const struct regval_list ov7670_default_regs[] PROGMEM = {//from the linux driver
  { REG_COM7, COM7_RESET },
  { REG_TSLB, 0x04 }, /* OV */
  { REG_COM7, 0 },  /* VGA */
  /*
  * Set the hardware window.  These values from OV don't entirely
  * make sense - hstop is less than hstart.  But they work...
  */
  { REG_HSTART, 0x13 }, { REG_HSTOP, 0x01 },
  { REG_HREF, 0xb6 }, { REG_VSTART, 0x02 },
  { REG_VSTOP, 0x7a }, { REG_VREF, 0x0a },

  { REG_COM3, 0 }, { REG_COM14, 0 },
  /* Mystery scaling numbers */
  { 0x70, 0x3a }, { 0x71, 0x35 },
  { 0x72, 0x11 }, { 0x73, 0xf0 },
  { 0xa2,/* 0x02 changed to 1*/1 }, { REG_COM10, 0x0 },
  /* Gamma curve values */
  { 0x7a, 0x20 }, { 0x7b, 0x10 },
  { 0x7c, 0x1e }, { 0x7d, 0x35 },
  { 0x7e, 0x5a }, { 0x7f, 0x69 },
  { 0x80, 0x76 }, { 0x81, 0x80 },
  { 0x82, 0x88 }, { 0x83, 0x8f },
  { 0x84, 0x96 }, { 0x85, 0xa3 },
  { 0x86, 0xaf }, { 0x87, 0xc4 },
  { 0x88, 0xd7 }, { 0x89, 0xe8 },
  /* AGC and AEC parameters.  Note we start by disabling those features,
  then turn them only after tweaking the values. */
  { REG_COM8, COM8_FASTAEC | COM8_AECSTEP },
  { REG_GAIN, 0 }, { REG_AECH, 0 },
  { REG_COM4, 0x40 }, /* magic reserved bit */
  { REG_COM9, 0x18 }, /* 4x gain + magic rsvd bit */
  { REG_BD50MAX, 0x05 }, { REG_BD60MAX, 0x07 },
  { REG_AEW, 0x95 }, { REG_AEB, 0x33 },
  { REG_VPT, 0xe3 }, { REG_HAECC1, 0x78 },
  { REG_HAECC2, 0x68 }, { 0xa1, 0x03 }, /* magic */
  { REG_HAECC3, 0xd8 }, { REG_HAECC4, 0xd8 },
  { REG_HAECC5, 0xf0 }, { REG_HAECC6, 0x90 },
  { REG_HAECC7, 0x94 },
  { REG_COM8, COM8_FASTAEC | COM8_AECSTEP | COM8_AGC | COM8_AEC },
  { 0x30, 0 }, { 0x31, 0 },//disable some delays
  /* Almost all of these are magic "reserved" values.  */
  { REG_COM5, 0x61 }, { REG_COM6, 0x4b },
  { 0x16, 0x02 }, { REG_MVFP, 0x07 },
  { 0x21, 0x02 }, { 0x22, 0x91 },
  { 0x29, 0x07 }, { 0x33, 0x0b },
  { 0x35, 0x0b }, { 0x37, 0x1d },
  { 0x38, 0x71 }, { 0x39, 0x2a },
  { REG_COM12, 0x78 }, { 0x4d, 0x40 },
  { 0x4e, 0x20 }, { REG_GFIX, 0 },
  /*{0x6b, 0x4a},*/{ 0x74, 0x10 },
  { 0x8d, 0x4f }, { 0x8e, 0 },
  { 0x8f, 0 }, { 0x90, 0 },
  { 0x91, 0 }, { 0x96, 0 },
  { 0x9a, 0 }, { 0xb0, 0x84 },
  { 0xb1, 0x0c }, { 0xb2, 0x0e },
  { 0xb3, 0x82 }, { 0xb8, 0x0a },

  /* More reserved magic, some of which tweaks white balance */
  { 0x43, 0x0a }, { 0x44, 0xf0 },
  { 0x45, 0x34 }, { 0x46, 0x58 },
  { 0x47, 0x28 }, { 0x48, 0x3a },
  { 0x59, 0x88 }, { 0x5a, 0x88 },
  { 0x5b, 0x44 }, { 0x5c, 0x67 },
  { 0x5d, 0x49 }, { 0x5e, 0x0e },
  { 0x6c, 0x0a }, { 0x6d, 0x55 },
  { 0x6e, 0x11 }, { 0x6f, 0x9e }, /* it was 0x9F "9e for advance AWB" */
  { 0x6a, 0x40 }, { REG_BLUE, 0x40 },
  { REG_RED, 0x60 },
  { REG_COM8, COM8_FASTAEC | COM8_AECSTEP | COM8_AGC | COM8_AEC | COM8_AWB },

  /* Matrix coefficients */
  { 0x4f, 0x80 }, { 0x50, 0x80 },
  { 0x51, 0 },    { 0x52, 0x22 },
  { 0x53, 0x5e }, { 0x54, 0x80 },
  { 0x58, 0x9e },

  { REG_COM16, COM16_AWBGAIN }, { REG_EDGE, 0 },
  { 0x75, 0x05 }, { REG_REG76, 0xe1 },
  { 0x4c, 0 },     { 0x77, 0x01 },
  { REG_COM13, /*0xc3*/0x48 }, { 0x4b, 0x09 },
  { 0xc9, 0x60 },   /*{REG_COM16, 0x38},*/
  { 0x56, 0x40 },

  { 0x34, 0x11 }, { REG_COM11, COM11_EXP | COM11_HZAUTO },
  { 0xa4, 0x82/*Was 0x88*/ }, { 0x96, 0 },
  { 0x97, 0x30 }, { 0x98, 0x20 },
  { 0x99, 0x30 }, { 0x9a, 0x84 },
  { 0x9b, 0x29 }, { 0x9c, 0x03 },
  { 0x9d, 0x4c }, { 0x9e, 0x3f },
  { 0x78, 0x04 },

  /* Extra-weird stuff.  Some sort of multiplexor register */
  { 0x79, 0x01 }, { 0xc8, 0xf0 },
  { 0x79, 0x0f }, { 0xc8, 0x00 },
  { 0x79, 0x10 }, { 0xc8, 0x7e },
  { 0x79, 0x0a }, { 0xc8, 0x80 },
  { 0x79, 0x0b }, { 0xc8, 0x01 },
  { 0x79, 0x0c }, { 0xc8, 0x0f },
  { 0x79, 0x0d }, { 0xc8, 0x20 },
  { 0x79, 0x09 }, { 0xc8, 0x80 },
  { 0x79, 0x02 }, { 0xc8, 0xc0 },
  { 0x79, 0x03 }, { 0xc8, 0x40 },
  { 0x79, 0x05 }, { 0xc8, 0x30 },
  { 0x79, 0x26 },
  { 0xff, 0xff }, /* END MARKER */
};

void error_led(void){
  DDRB |= 32;//make sure led is output
  while (1){//wait for reset
    PORTB ^= 32;// toggle led
    _delay_ms(100);
  }
}

void twiStart(void){
  TWCR = _BV(TWINT) | _BV(TWSTA) | _BV(TWEN);//send start
  while (!(TWCR & (1 << TWINT)));//wait for start to be transmitted
  if ((TWSR & 0xF8) != TW_START)
    error_led();
}

void twiWriteByte(uint8_t DATA, uint8_t type){
  TWDR = DATA;
  TWCR = _BV(TWINT) | _BV(TWEN);
  while (!(TWCR & (1 << TWINT))) {}
  if ((TWSR & 0xF8) != type)
    error_led();
}

void twiAddr(uint8_t addr, uint8_t typeTWI){
  TWDR = addr;//send address
  TWCR = _BV(TWINT) | _BV(TWEN);    /* clear interrupt to start transmission */
  while ((TWCR & _BV(TWINT)) == 0); /* wait for transmission */
  if ((TWSR & 0xF8) != typeTWI)
    error_led();
}

void wrReg(uint8_t reg, uint8_t dat){
  //send start condition
  twiStart();
  twiAddr(camAddr_WR, TW_MT_SLA_ACK);
  twiWriteByte(reg, TW_MT_DATA_ACK);
  twiWriteByte(dat, TW_MT_DATA_ACK);
  TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);//send stop
  _delay_ms(1);
}

static uint8_t twiRd(uint8_t nack){
  if (nack){
    TWCR = _BV(TWINT) | _BV(TWEN);
    while ((TWCR & _BV(TWINT)) == 0); /* wait for transmission */
    if ((TWSR & 0xF8) != TW_MR_DATA_NACK)
      error_led();
    return TWDR;
  }
  else{
    TWCR = _BV(TWINT) | _BV(TWEN) | _BV(TWEA);
    while ((TWCR & _BV(TWINT)) == 0); /* wait for transmission */
    if ((TWSR & 0xF8) != TW_MR_DATA_ACK)
      error_led();
    return TWDR;
  }
}

uint8_t rdReg(uint8_t reg){
  uint8_t dat;
  twiStart();
  twiAddr(camAddr_WR, TW_MT_SLA_ACK);
  twiWriteByte(reg, TW_MT_DATA_ACK);
  TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);//send stop
  _delay_ms(1);
  twiStart();
  twiAddr(camAddr_RD, TW_MR_SLA_ACK);
  dat = twiRd(1);
  TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);//send stop
  _delay_ms(1);
  return dat;
}

void wrSensorRegs8_8(const struct regval_list reglist[]){
  uint8_t reg_addr, reg_val;
  const struct regval_list *next = reglist;
  while ((reg_addr != 0xff) | (reg_val != 0xff)){
    reg_addr = pgm_read_byte(&next->reg_num);
    reg_val = pgm_read_byte(&next->value);
    wrReg(reg_addr, reg_val);
    next++;
  }
}

void setColor(void){
  wrSensorRegs8_8(yuv422_ov7670);
}

void setRes(void){
  wrReg(REG_COM3, 4); // REG_COM3 enable scaling
  wrSensorRegs8_8(qvga_ov7670);
}

void camInit(void){
  wrReg(0x12, 0x80);
  _delay_ms(100);
  wrSensorRegs8_8(ov7670_default_regs);
  wrReg(REG_COM10, 32);//PCLK does not toggle on HBLANK.
}

void arduinoUnoInut(void) {
  cli();//disable interrupts

    /* Setup the 8mhz PWM clock
  * This will be on pin 11*/
  DDRB |= (1 << 3);//pin 11
  ASSR &= ~(_BV(EXCLK) | _BV(AS2));
  TCCR2A = (1 << COM2A0) | (1 << WGM21) | (1 << WGM20);
  TCCR2B = (1 << WGM22) | (1 << CS20);
  OCR2A = 0;//(F_CPU)/(2*(X+1))
  DDRC &= ~15;//low d0-d3 camera
  DDRD &= ~252;//d7-d4 and interrupt pins
  _delay_ms(3000);

    //set up twi for 100khz
  TWSR &= ~3;//disable prescaler for TWI
  TWBR = 72;//set to 100khz

    //enable serial
  UBRR0H = 0;
  UBRR0L = 1;//0 = 2M baud rate. 1 = 1M baud. 3 = 0.5M. 7 = 250k 207 is 9600 baud rate.
  UCSR0A |= 2;//double speed aysnc
  UCSR0B = (1 << RXEN0) | (1 << TXEN0);//Enable receiver and transmitter
  UCSR0C = 6;//async 1 stop bit 8bit char no parity bits
}

void StringPgm(const char * str){
  do{
      while (!(UCSR0A & (1 << UDRE0)));//wait for byte to transmit
      UDR0 = pgm_read_byte_near(str);
      while (!(UCSR0A & (1 << UDRE0)));//wait for byte to transmit
  } while (pgm_read_byte_near(++str));
}

static void captureImg(uint16_t wg, uint16_t hg){
  uint16_t y, x;

  StringPgm(PSTR("*RDY*"));

  while (!(PIND & 8));//wait for high
  while ((PIND & 8));//wait for low

    y = hg;
  while (y--){
        x = wg;
      //while (!(PIND & 256));//wait for high
    while (x--){
      while ((PIND & 4));//wait for low
            UDR0 = (PINC & 15) | (PIND & 240);
          while (!(UCSR0A & (1 << UDRE0)));//wait for byte to transmit
      while (!(PIND & 4));//wait for high
      while ((PIND & 4));//wait for low
      while (!(PIND & 4));//wait for high
    }
    //  while ((PIND & 256));//wait for low
  }
    _delay_ms(100);
}

void setup(){
  arduinoUnoInut();
  camInit();
  setRes();
  setColor();
  wrReg(0x11, 12); //Earlier it had the value: wrReg(0x11, 12); New version works better for me :) !!!!
}

void loop(){
  captureImg(320, 240);
}

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// Source code for application to transmit image from ov7670 to PC via USB

// By Siarhei Charkes in 2015

// http://privateblog.info

#include <stdint.h>

#include <avr/io.h>

#include <util/twi.h>

#include <util/delay.h>

#include <avr/pgmspace.h>

#define F_CPU 16000000UL

#define vga 0

#define qvga 1

#define qqvga 2

#define yuv422 0

#define rgb565 1

#define bayerRGB 2

#define camAddr_WR 0x42

#define camAddr_RD 0x43

/* Registers */

#define REG_GAIN 0x00 /* Gain lower 8 bits (rest in vref) */

#define REG_BLUE 0x01 /* blue gain */

#define REG_RED 0x02 /* red gain */

#define REG_VREF 0x03 /* Pieces of GAIN, VSTART, VSTOP */

#define REG_COM1 0x04 /* Control 1 */

#define COM1_CCIR656 0x40 /* CCIR656 enable */

#define REG_BAVE 0x05 /* U/B Average level */

#define REG_GbAVE 0x06 /* Y/Gb Average level */

#define REG_AECHH 0x07 /* AEC MS 5 bits */

#define REG_RAVE 0x08 /* V/R Average level */

#define REG_COM2 0x09 /* Control 2 */

#define COM2_SSLEEP 0x10 /* Soft sleep mode */

#define REG_PID 0x0a /* Product ID MSB */

#define REG_VER 0x0b /* Product ID LSB */

#define REG_COM3 0x0c /* Control 3 */

#define COM3_SWAP 0x40 /* Byte swap */

#define COM3_SCALEEN 0x08 /* Enable scaling */

#define COM3_DCWEN 0x04 /* Enable downsamp/crop/window */

#define REG_COM4 0x0d /* Control 4 */

#define REG_COM5 0x0e /* All "reserved" */

#define REG_COM6 0x0f /* Control 6 */

#define REG_AECH 0x10 /* More bits of AEC value */

#define REG_CLKRC 0x11 /* Clocl control */

#define CLK_EXT 0x40 /* Use external clock directly */

#define CLK_SCALE 0x3f /* Mask for internal clock scale */

#define REG_COM7 0x12 /* Control 7 */ //REG mean address.

#define COM7_RESET 0x80 /* Register reset */

#define COM7_FMT_MASK 0x38

#define COM7_FMT_VGA 0x00

#define COM7_FMT_CIF 0x20 /* CIF format */

#define COM7_FMT_QVGA 0x10 /* QVGA format */

#define COM7_FMT_QCIF 0x08 /* QCIF format */

#define COM7_RGB 0x04 /* bits 0 and 2 - RGB format */

#define COM7_YUV 0x00 /* YUV */

#define COM7_BAYER 0x01 /* Bayer format */

#define COM7_PBAYER 0x05 /* "Processed bayer" */

#define REG_COM8 0x13 /* Control 8 */

#define COM8_FASTAEC 0x80 /* Enable fast AGC/AEC */

#define COM8_AECSTEP 0x40 /* Unlimited AEC step size */

#define COM8_BFILT 0x20 /* Band filter enable */

#define COM8_AGC 0x04 /* Auto gain enable */

#define COM8_AWB 0x02 /* White balance enable */

#define COM8_AEC 0x01 /* Auto exposure enable */

#define REG_COM9 0x14 /* Control 9- gain ceiling */

#define REG_COM10 0x15 /* Control 10 */

#define COM10_HSYNC 0x40 /* HSYNC instead of HREF */

#define COM10_PCLK_HB 0x20 /* Suppress PCLK on horiz blank */

#define COM10_HREF_REV 0x08 /* Reverse HREF */

#define COM10_VS_LEAD 0x04 /* VSYNC on clock leading edge */

#define COM10_VS_NEG 0x02 /* VSYNC negative */

#define COM10_HS_NEG 0x01 /* HSYNC negative */

#define REG_HSTART 0x17 /* Horiz start high bits */

#define REG_HSTOP 0x18 /* Horiz stop high bits */

#define REG_VSTART 0x19 /* Vert start high bits */

#define REG_VSTOP 0x1a /* Vert stop high bits */

#define REG_PSHFT 0x1b /* Pixel delay after HREF */

#define REG_MIDH 0x1c /* Manuf. ID high */

#define REG_MIDL 0x1d /* Manuf. ID low */

#define REG_MVFP 0x1e /* Mirror / vflip */

#define MVFP_MIRROR 0x20 /* Mirror image */

#define MVFP_FLIP 0x10 /* Vertical flip */

#define REG_AEW 0x24 /* AGC upper limit */

#define REG_AEB 0x25 /* AGC lower limit */

#define REG_VPT 0x26 /* AGC/AEC fast mode op region */

#define REG_HSYST 0x30 /* HSYNC rising edge delay */

#define REG_HSYEN 0x31 /* HSYNC falling edge delay */

#define REG_HREF 0x32 /* HREF pieces */

#define REG_TSLB 0x3a /* lots of stuff */

#define TSLB_YLAST 0x04 /* UYVY or VYUY - see com13 */

#define REG_COM11 0x3b /* Control 11 */

#define COM11_NIGHT 0x80 /* NIght mode enable */

#define COM11_NMFR 0x60 /* Two bit NM frame rate */

#define COM11_HZAUTO 0x10 /* Auto detect 50/60 Hz */

#define COM11_50HZ 0x08 /* Manual 50Hz select */

#define COM11_EXP 0x02

#define REG_COM12 0x3c /* Control 12 */

#define COM12_HREF 0x80 /* HREF always */

#define REG_COM13 0x3d /* Control 13 */

#define COM13_GAMMA 0x80 /* Gamma enable */

#define COM13_UVSAT 0x40 /* UV saturation auto adjustment */

#define COM13_UVSWAP 0x01 /* V before U - w/TSLB */

#define REG_COM14 0x3e /* Control 14 */

#define COM14_DCWEN 0x10 /* DCW/PCLK-scale enable */

#define REG_EDGE 0x3f /* Edge enhancement factor */

#define REG_COM15 0x40 /* Control 15 */

#define COM15_R10F0 0x00 /* Data range 10 to F0 */

#define COM15_R01FE 0x80 /* 01 to FE */

#define COM15_R00FF 0xc0 /* 00 to FF */

#define COM15_RGB565 0x10 /* RGB565 output */

#define COM15_RGB555 0x30 /* RGB555 output */

#define REG_COM16 0x41 /* Control 16 */

#define COM16_AWBGAIN 0x08 /* AWB gain enable */

#define REG_COM17 0x42 /* Control 17 */

#define COM17_AECWIN 0xc0 /* AEC window - must match COM4 */

#define COM17_CBAR 0x08 /* DSP Color bar */

* This matrix defines how the colors are generated, must be

* tweaked to adjust hue and saturation.

* Order: v-red, v-green, v-blue, u-red, u-green, u-blue

* They are nine-bit signed quantities, with the sign bit

* stored in0x58.Sign for v-red is bit 0, and up from there.

#define REG_CMATRIX_BASE 0x4f

#define CMATRIX_LEN 6

#define REG_CMATRIX_SIGN 0x58

#define REG_BRIGHT 0x55 /* Brightness */

#define REG_CONTRAS 0x56 /* Contrast control */

#define REG_GFIX 0x69 /* Fix gain control */

#define REG_REG76 0x76 /* OV's name */

#define R76_BLKPCOR 0x80 /* Black pixel correction enable */

#define R76_WHTPCOR 0x40 /* White pixel correction enable */

#define REG_RGB444 0x8c /* RGB 444 control */

#define R444_ENABLE 0x02 /* Turn on RGB444, overrides 5x5 */

#define R444_RGBX 0x01 /* Empty nibble at end */

#define REG_HAECC1 0x9f /* Hist AEC/AGC control 1 */

#define REG_HAECC2 0xa0 /* Hist AEC/AGC control 2 */

#define REG_BD50MAX 0xa5 /* 50hz banding step limit */

#define REG_HAECC3 0xa6 /* Hist AEC/AGC control 3 */

#define REG_HAECC4 0xa7 /* Hist AEC/AGC control 4 */

#define REG_HAECC5 0xa8 /* Hist AEC/AGC control 5 */

#define REG_HAECC6 0xa9 /* Hist AEC/AGC control 6 */

#define REG_HAECC7 0xaa /* Hist AEC/AGC control 7 */

#define REG_BD60MAX 0xab /* 60hz banding step limit */

#define REG_GAIN 0x00 /* Gain lower 8 bits (rest in vref) */

#define REG_BLUE 0x01 /* blue gain */

#define REG_RED 0x02 /* red gain */

#define REG_VREF 0x03 /* Pieces of GAIN, VSTART, VSTOP */

#define REG_COM1 0x04 /* Control 1 */

#define COM1_CCIR656 0x40 /* CCIR656 enable */

#define REG_BAVE 0x05 /* U/B Average level */

#define REG_GbAVE 0x06 /* Y/Gb Average level */

#define REG_AECHH 0x07 /* AEC MS 5 bits */

#define REG_RAVE 0x08 /* V/R Average level */

#define REG_COM2 0x09 /* Control 2 */

#define COM2_SSLEEP 0x10 /* Soft sleep mode */

#define REG_PID 0x0a /* Product ID MSB */

#define REG_VER 0x0b /* Product ID LSB */

#define REG_COM3 0x0c /* Control 3 */

#define COM3_SWAP 0x40 /* Byte swap */

#define COM3_SCALEEN 0x08 /* Enable scaling */

#define COM3_DCWEN 0x04 /* Enable downsamp/crop/window */

#define REG_COM4 0x0d /* Control 4 */

#define REG_COM5 0x0e /* All "reserved" */

#define REG_COM6 0x0f /* Control 6 */

#define REG_AECH 0x10 /* More bits of AEC value */

#define REG_CLKRC 0x11 /* Clocl control */

#define CLK_EXT 0x40 /* Use external clock directly */

#define CLK_SCALE 0x3f /* Mask for internal clock scale */

#define REG_COM7 0x12 /* Control 7 */

#define COM7_RESET 0x80 /* Register reset */

#define COM7_FMT_MASK 0x38

#define COM7_FMT_VGA 0x00

#define COM7_FMT_CIF 0x20 /* CIF format */

#define COM7_FMT_QVGA 0x10 /* QVGA format */

#define COM7_FMT_QCIF 0x08 /* QCIF format */

#define COM7_RGB 0x04 /* bits 0 and 2 - RGB format */

#define COM7_YUV 0x00 /* YUV */

#define COM7_BAYER 0x01 /* Bayer format */

#define COM7_PBAYER 0x05 /* "Processed bayer" */

#define REG_COM8 0x13 /* Control 8 */

#define COM8_FASTAEC 0x80 /* Enable fast AGC/AEC */

#define COM8_AECSTEP 0x40 /* Unlimited AEC step size */

#define COM8_BFILT 0x20 /* Band filter enable */

#define COM8_AGC 0x04 /* Auto gain enable */

#define COM8_AWB 0x02 /* White balance enable */

#define COM8_AEC 0x01 /* Auto exposure enable */

#define REG_COM9 0x14 /* Control 9- gain ceiling */

#define REG_COM10 0x15 /* Control 10 */

#define COM10_HSYNC 0x40 /* HSYNC instead of HREF */

#define COM10_PCLK_HB 0x20 /* Suppress PCLK on horiz blank */

#define COM10_HREF_REV 0x08 /* Reverse HREF */

#define COM10_VS_LEAD 0x04 /* VSYNC on clock leading edge */

#define COM10_VS_NEG 0x02 /* VSYNC negative */

#define COM10_HS_NEG 0x01 /* HSYNC negative */

#define REG_HSTART 0x17 /* Horiz start high bits */

#define REG_HSTOP 0x18 /* Horiz stop high bits */

#define REG_VSTART 0x19 /* Vert start high bits */

#define REG_VSTOP 0x1a /* Vert stop high bits */

#define REG_PSHFT 0x1b /* Pixel delay after HREF */

#define REG_MIDH 0x1c /* Manuf. ID high */

#define REG_MIDL 0x1d /* Manuf. ID low */

#define REG_MVFP 0x1e /* Mirror / vflip */

#define MVFP_MIRROR 0x20 /* Mirror image */

#define MVFP_FLIP 0x10 /* Vertical flip */

#define REG_AEW 0x24 /* AGC upper limit */

#define REG_AEB 0x25 /* AGC lower limit */

#define REG_VPT 0x26 /* AGC/AEC fast mode op region */

#define REG_HSYST 0x30 /* HSYNC rising edge delay */

#define REG_HSYEN 0x31 /* HSYNC falling edge delay */

#define REG_HREF 0x32 /* HREF pieces */

#define REG_TSLB 0x3a /* lots of stuff */

#define TSLB_YLAST 0x04 /* UYVY or VYUY - see com13 */

#define REG_COM11 0x3b /* Control 11 */

#define COM11_NIGHT 0x80 /* NIght mode enable */

#define COM11_NMFR 0x60 /* Two bit NM frame rate */

#define COM11_HZAUTO 0x10 /* Auto detect 50/60 Hz */

#define COM11_50HZ 0x08 /* Manual 50Hz select */

#define COM11_EXP 0x02

#define REG_COM12 0x3c /* Control 12 */

#define COM12_HREF 0x80 /* HREF always */

#define REG_COM13 0x3d /* Control 13 */

#define COM13_GAMMA 0x80 /* Gamma enable */

#define COM13_UVSAT 0x40 /* UV saturation auto adjustment */

#define COM13_UVSWAP 0x01 /* V before U - w/TSLB */

#define REG_COM14 0x3e /* Control 14 */

#define COM14_DCWEN 0x10 /* DCW/PCLK-scale enable */

#define REG_EDGE 0x3f /* Edge enhancement factor */

#define REG_COM15 0x40 /* Control 15 */

#define COM15_R10F0 0x00 /* Data range 10 to F0 */

#define COM15_R01FE 0x80 /* 01 to FE */

#define COM15_R00FF 0xc0 /* 00 to FF */

#define COM15_RGB565 0x10 /* RGB565 output */

#define COM15_RGB555 0x30 /* RGB555 output */

#define REG_COM16 0x41 /* Control 16 */

#define COM16_AWBGAIN 0x08 /* AWB gain enable */

#define REG_COM17 0x42 /* Control 17 */

#define COM17_AECWIN 0xc0 /* AEC window - must match COM4 */

#define COM17_CBAR 0x08 /* DSP Color bar */

#define CMATRIX_LEN 6

#define REG_BRIGHT 0x55 /* Brightness */

#define REG_REG76 0x76 /* OV's name */

#define R76_BLKPCOR 0x80 /* Black pixel correction enable */

#define R76_WHTPCOR 0x40 /* White pixel correction enable */

#define REG_RGB444 0x8c /* RGB 444 control */

#define R444_ENABLE 0x02 /* Turn on RGB444, overrides 5x5 */

#define R444_RGBX 0x01 /* Empty nibble at end */

#define REG_HAECC1 0x9f /* Hist AEC/AGC control 1 */

#define REG_HAECC2 0xa0 /* Hist AEC/AGC control 2 */

#define REG_BD50MAX 0xa5 /* 50hz banding step limit */

#define REG_HAECC3 0xa6 /* Hist AEC/AGC control 3 */

#define REG_HAECC4 0xa7 /* Hist AEC/AGC control 4 */

#define REG_HAECC5 0xa8 /* Hist AEC/AGC control 5 */

#define REG_HAECC6 0xa9 /* Hist AEC/AGC control 6 */

#define REG_HAECC7 0xaa /* Hist AEC/AGC control 7 */

#define REG_BD60MAX 0xab /* 60hz banding step limit */

#define MTX1 0x4f /* Matrix Coefficient 1 */

#define MTX2 0x50 /* Matrix Coefficient 2 */

#define MTX3 0x51 /* Matrix Coefficient 3 */

#define MTX4 0x52 /* Matrix Coefficient 4 */

#define MTX5 0x53 /* Matrix Coefficient 5 */

#define MTX6 0x54 /* Matrix Coefficient 6 */

#define REG_CONTRAS 0x56 /* Contrast control */

#define MTXS 0x58 /* Matrix Coefficient Sign */

#define AWBC7 0x59 /* AWB Control 7 */

#define AWBC8 0x5a /* AWB Control 8 */

#define AWBC9 0x5b /* AWB Control 9 */

#define AWBC10 0x5c /* AWB Control 10 */

#define AWBC11 0x5d /* AWB Control 11 */

#define AWBC12 0x5e /* AWB Control 12 */

#define REG_GFI 0x69 /* Fix gain control */

#define GGAIN 0x6a /* G Channel AWB Gain */

#define DBLV 0x6b

#define AWBCTR3 0x6c /* AWB Control 3 */

#define AWBCTR2 0x6d /* AWB Control 2 */

#define AWBCTR1 0x6e /* AWB Control 1 */

#define AWBCTR0 0x6f /* AWB Control 0 */

struct regval_list{

uint8_t reg_num;

uint16_t value;

};

const struct regval_list qvga_ov7670[] PROGMEM = {

{ REG_COM14, 0x19 },

{ 0x72, 0x11 },

{ 0x73, 0xf1 },

{ REG_HSTART, 0x16 },

{ REG_HSTOP, 0x04 },

{ REG_HREF, 0xa4 },

{ REG_VSTART, 0x02 },

{ REG_VSTOP, 0x7a },

{ REG_VREF, 0x0a },

/* { REG_HSTART, 0x16 },

{ REG_HSTOP, 0x04 },

{ REG_HREF, 0x24 },

{ REG_VSTART, 0x02 },

{ REG_VSTOP, 0x7a },

{ REG_VREF, 0x0a },*/

{ 0xff, 0xff }, /* END MARKER */

};

const struct regval_list yuv422_ov7670[] PROGMEM = {

{ REG_COM7, 0x0 }, /* Selects YUV mode */

{ REG_RGB444, 0 }, /* No RGB444 please */

{ REG_COM1, 0 },

{ REG_COM15, COM15_R00FF },

{ REG_COM9, 0x6A }, /* 128x gain ceiling; 0x8 is reserved bit */

{ 0x4f, 0x80 }, /* "matrix coefficient 1" */

{ 0x50, 0x80 }, /* "matrix coefficient 2" */

{ 0x51, 0 }, /* vb */

{ 0x52, 0x22 }, /* "matrix coefficient 4" */

{ 0x53, 0x5e }, /* "matrix coefficient 5" */

{ 0x54, 0x80 }, /* "matrix coefficient 6" */

{ REG_COM13, COM13_UVSAT },

{ 0xff, 0xff }, /* END MARKER */

};

const struct regval_list ov7670_default_regs[] PROGMEM = {//from the linux driver

{ REG_COM7, COM7_RESET },

{ REG_TSLB, 0x04 }, /* OV */

{ REG_COM7, 0 }, /* VGA */

* Set the hardware window. These values from OV don't entirely

* make sense - hstop is less than hstart. But they work...

{ REG_HSTART, 0x13 }, { REG_HSTOP, 0x01 },

{ REG_HREF, 0xb6 }, { REG_VSTART, 0x02 },

{ REG_VSTOP, 0x7a }, { REG_VREF, 0x0a },

{ REG_COM3, 0 }, { REG_COM14, 0 },

/* Mystery scaling numbers */

{ 0x70, 0x3a }, { 0x71, 0x35 },

{ 0x72, 0x11 }, { 0x73, 0xf0 },

{ 0xa2,/* 0x02 changed to 1*/1 }, { REG_COM10, 0x0 },

/* Gamma curve values */

{ 0x7a, 0x20 }, { 0x7b, 0x10 },

{ 0x7c, 0x1e }, { 0x7d, 0x35 },

{ 0x7e, 0x5a }, { 0x7f, 0x69 },

{ 0x80, 0x76 }, { 0x81, 0x80 },

{ 0x82, 0x88 }, { 0x83, 0x8f },

{ 0x84, 0x96 }, { 0x85, 0xa3 },

{ 0x86, 0xaf }, { 0x87, 0xc4 },

{ 0x88, 0xd7 }, { 0x89, 0xe8 },

/* AGC and AEC parameters. Note we start by disabling those features,

then turn them only after tweaking the values. */

{ REG_COM8, COM8_FASTAEC | COM8_AECSTEP },

{ REG_GAIN, 0 }, { REG_AECH, 0 },

{ REG_COM4, 0x40 }, /* magic reserved bit */

{ REG_COM9, 0x18 }, /* 4x gain + magic rsvd bit */

{ REG_BD50MAX, 0x05 }, { REG_BD60MAX, 0x07 },

{ REG_AEW, 0x95 }, { REG_AEB, 0x33 },

{ REG_VPT, 0xe3 }, { REG_HAECC1, 0x78 },

{ REG_HAECC2, 0x68 }, { 0xa1, 0x03 }, /* magic */

{ REG_HAECC3, 0xd8 }, { REG_HAECC4, 0xd8 },

{ REG_HAECC5, 0xf0 }, { REG_HAECC6, 0x90 },

{ REG_HAECC7, 0x94 },

{ REG_COM8, COM8_FASTAEC | COM8_AECSTEP | COM8_AGC | COM8_AEC },

{ 0x30, 0 }, { 0x31, 0 },//disable some delays

/* Almost all of these are magic "reserved" values. */

{ REG_COM5, 0x61 }, { REG_COM6, 0x4b },

{ 0x16, 0x02 }, { REG_MVFP, 0x07 },

{ 0x21, 0x02 }, { 0x22, 0x91 },

{ 0x29, 0x07 }, { 0x33, 0x0b },

{ 0x35, 0x0b }, { 0x37, 0x1d },

{ 0x38, 0x71 }, { 0x39, 0x2a },

{ REG_COM12, 0x78 }, { 0x4d, 0x40 },

{ 0x4e, 0x20 }, { REG_GFIX, 0 },

/*{0x6b, 0x4a},*/{ 0x74, 0x10 },

{ 0x8d, 0x4f }, { 0x8e, 0 },

{ 0x8f, 0 }, { 0x90, 0 },

{ 0x91, 0 }, { 0x96, 0 },

{ 0x9a, 0 }, { 0xb0, 0x84 },

{ 0xb1, 0x0c }, { 0xb2, 0x0e },

{ 0xb3, 0x82 }, { 0xb8, 0x0a },

/* More reserved magic, some of which tweaks white balance */

{ 0x43, 0x0a }, { 0x44, 0xf0 },

{ 0x45, 0x34 }, { 0x46, 0x58 },

{ 0x47, 0x28 }, { 0x48, 0x3a },

{ 0x59, 0x88 }, { 0x5a, 0x88 },

{ 0x5b, 0x44 }, { 0x5c, 0x67 },

{ 0x5d, 0x49 }, { 0x5e, 0x0e },

{ 0x6c, 0x0a }, { 0x6d, 0x55 },

{ 0x6e, 0x11 }, { 0x6f, 0x9e }, /* it was 0x9F "9e for advance AWB" */

{ 0x6a, 0x40 }, { REG_BLUE, 0x40 },

{ REG_RED, 0x60 },

{ REG_COM8, COM8_FASTAEC | COM8_AECSTEP | COM8_AGC | COM8_AEC | COM8_AWB },

/* Matrix coefficients */

{ 0x4f, 0x80 }, { 0x50, 0x80 },

{ 0x51, 0 }, { 0x52, 0x22 },

{ 0x53, 0x5e }, { 0x54, 0x80 },

{ 0x58, 0x9e },

{ REG_COM16, COM16_AWBGAIN }, { REG_EDGE, 0 },

{ 0x75, 0x05 }, { REG_REG76, 0xe1 },

{ 0x4c, 0 }, { 0x77, 0x01 },

{ REG_COM13, /*0xc3*/0x48 }, { 0x4b, 0x09 },

{ 0xc9, 0x60 }, /*{REG_COM16, 0x38},*/

{ 0x56, 0x40 },

{ 0x34, 0x11 }, { REG_COM11, COM11_EXP | COM11_HZAUTO },

{ 0xa4, 0x82/*Was 0x88*/ }, { 0x96, 0 },

{ 0x97, 0x30 }, { 0x98, 0x20 },

{ 0x99, 0x30 }, { 0x9a, 0x84 },

{ 0x9b, 0x29 }, { 0x9c, 0x03 },

{ 0x9d, 0x4c }, { 0x9e, 0x3f },

{ 0x78, 0x04 },

/* Extra-weird stuff. Some sort of multiplexor register */

{ 0x79, 0x01 }, { 0xc8, 0xf0 },

{ 0x79, 0x0f }, { 0xc8, 0x00 },

{ 0x79, 0x10 }, { 0xc8, 0x7e },

{ 0x79, 0x0a }, { 0xc8, 0x80 },

{ 0x79, 0x0b }, { 0xc8, 0x01 },

{ 0x79, 0x0c }, { 0xc8, 0x0f },

{ 0x79, 0x0d }, { 0xc8, 0x20 },

{ 0x79, 0x09 }, { 0xc8, 0x80 },

{ 0x79, 0x02 }, { 0xc8, 0xc0 },

{ 0x79, 0x03 }, { 0xc8, 0x40 },

{ 0x79, 0x05 }, { 0xc8, 0x30 },

{ 0x79, 0x26 },

{ 0xff, 0xff }, /* END MARKER */

};

void error_led(void){

DDRB |= 32;//make sure led is output

while (1){//wait for reset

PORTB ^= 32;// toggle led

_delay_ms(100);

}

void twiStart(void){

TWCR = _BV(TWINT) | _BV(TWSTA) | _BV(TWEN);//send start

while (!(TWCR & (1 << TWINT)));//wait for start to be transmitted

if ((TWSR & 0xF8) != TW_START)

error_led();

}

void twiWriteByte(uint8_t DATA, uint8_t type){

TWDR = DATA;

TWCR = _BV(TWINT) | _BV(TWEN);

while (!(TWCR & (1 << TWINT))) {}

if ((TWSR & 0xF8) != type)

error_led();

}

void twiAddr(uint8_t addr, uint8_t typeTWI){

TWDR = addr;//send address

TWCR = _BV(TWINT) | _BV(TWEN); /* clear interrupt to start transmission */

while ((TWCR & _BV(TWINT)) == 0); /* wait for transmission */

if ((TWSR & 0xF8) != typeTWI)

error_led();

}

void wrReg(uint8_t reg, uint8_t dat){

//send start condition

twiStart();

twiAddr(camAddr_WR, TW_MT_SLA_ACK);

twiWriteByte(reg, TW_MT_DATA_ACK);

twiWriteByte(dat, TW_MT_DATA_ACK);

TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);//send stop

_delay_ms(1);

}

static uint8_t twiRd(uint8_t nack){

if (nack){

TWCR = _BV(TWINT) | _BV(TWEN);

while ((TWCR & _BV(TWINT)) == 0); /* wait for transmission */

if ((TWSR & 0xF8) != TW_MR_DATA_NACK)

error_led();

return TWDR;

}

else{

TWCR = _BV(TWINT) | _BV(TWEN) | _BV(TWEA);

while ((TWCR & _BV(TWINT)) == 0); /* wait for transmission */

if ((TWSR & 0xF8) != TW_MR_DATA_ACK)

error_led();

return TWDR;

}

uint8_t rdReg(uint8_t reg){

uint8_t dat;

twiStart();

twiAddr(camAddr_WR, TW_MT_SLA_ACK);

twiWriteByte(reg, TW_MT_DATA_ACK);

TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);//send stop

_delay_ms(1);

twiStart();

twiAddr(camAddr_RD, TW_MR_SLA_ACK);

dat = twiRd(1);

TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);//send stop

_delay_ms(1);

return dat;

}

void wrSensorRegs8_8(const struct regval_list reglist[]){

uint8_t reg_addr, reg_val;

const struct regval_list *next = reglist;

while ((reg_addr != 0xff) | (reg_val != 0xff)){

reg_addr = pgm_read_byte(&next->reg_num);

reg_val = pgm_read_byte(&next->value);

wrReg(reg_addr, reg_val);

next++;

}

void setColor(void){

wrSensorRegs8_8(yuv422_ov7670);

}

void setRes(void){

wrReg(REG_COM3, 4); // REG_COM3 enable scaling

wrSensorRegs8_8(qvga_ov7670);

}

void camInit(void){

wrReg(0x12, 0x80);

_delay_ms(100);

wrSensorRegs8_8(ov7670_default_regs);

wrReg(REG_COM10, 32);//PCLK does not toggle on HBLANK.

}

void arduinoUnoInut(void) {

cli();//disable interrupts

/* Setup the 8mhz PWM clock

* This will be on pin 11*/

DDRB |= (1 << 3);//pin 11

ASSR &= ~(_BV(EXCLK) | _BV(AS2));

TCCR2A = (1 << COM2A0) | (1 << WGM21) | (1 << WGM20);

TCCR2B = (1 << WGM22) | (1 << CS20);

OCR2A = 0;//(F_CPU)/(2*(X+1))

DDRC &= ~15;//low d0-d3 camera

DDRD &= ~252;//d7-d4 and interrupt pins

_delay_ms(3000);

//set up twi for 100khz

TWSR &= ~3;//disable prescaler for TWI

TWBR = 72;//set to 100khz

//enable serial

UBRR0H = 0;

UBRR0L = 1;//0 = 2M baud rate. 1 = 1M baud. 3 = 0.5M. 7 = 250k 207 is 9600 baud rate.

UCSR0A |= 2;//double speed aysnc

UCSR0B = (1 << RXEN0) | (1 << TXEN0);//Enable receiver and transmitter

UCSR0C = 6;//async 1 stop bit 8bit char no parity bits

}

void StringPgm(const char * str){

do{

while (!(UCSR0A & (1 << UDRE0)));//wait for byte to transmit

UDR0 = pgm_read_byte_near(str);

while (!(UCSR0A & (1 << UDRE0)));//wait for byte to transmit

} while (pgm_read_byte_near(++str));

}

static void captureImg(uint16_t wg, uint16_t hg){

uint16_t y, x;

StringPgm(PSTR("*RDY*"));

while (!(PIND & 8));//wait for high

while ((PIND & 8));//wait for low

y = hg;

while (y--){

x = wg;

//while (!(PIND & 256));//wait for high

while (x--){

while ((PIND & 4));//wait for low

UDR0 = (PINC & 15) | (PIND & 240);

while (!(UCSR0A & (1 << UDRE0)));//wait for byte to transmit

while (!(PIND & 4));//wait for high

while ((PIND & 4));//wait for low

while (!(PIND & 4));//wait for high

}

// while ((PIND & 256));//wait for low

}

_delay_ms(100);

}

void setup(){

arduinoUnoInut();

camInit();

setRes();

setColor();

wrReg(0x11, 12); //Earlier it had the value: wrReg(0x11, 12); New version works better for me :) !!!!

}

void loop(){

captureImg(320, 240);

}

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