I have read a great deal today about interfacing the OV7670 with the Arduino Uno. I decided to jump in and start tinkering with this thing. I wired it up according to this schematic:
And I copied and pasted the sketch I found here (http://www.instructables.com/id/OV7670-Without-FIFO-Very-Simple-Framecapture-With-/step3/Upload-sketch-to-Arduino/):
// 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, 11); //Earlier it had the value: wrReg(0x11, 12); New version works better for me :) !!!!
}
void loop(){
captureImg(320, 240);
}
The sketch has way too many #defines, and isn't exactly straightforward, but at least it loads, although there is one warning:
/Users/charles/Documents/Arduino/cameraTest2/cameraTest2.ino:13:0: warning: "F_CPU" redefined
#define F_CPU 16000000UL
^
<command-line>:0:0: note: this is the location of the previous definition
To validate that this does anything, I tried playing around with ComputerNerd's SimpleFrameGrabber, but I'm on a mac and I ran into problems when trying to ./build:
main.c:26:10: fatal error: 'SDL/SDL.h' file not found
#include <SDL/SDL.h>
I then tried opening up the Arduino IDE Serial Monitor, and am not seeing anything. Should I be seeing anything? I was expecting I would at least see gibberish..
Ideally, I would like to find some simple example code that would setup the camera (the defaults might even be just fine), and allow me to get RGB pixel data for a 320x240 or 640x480 image. If I could just print that to the Serial Output, I could then write a simple python script to save it as a jpg or a png or something.
I just need to get to a sanity state with this thing. Or find another inexpensive camera module that's easier to work with.
