PicOV7670

This project demonstrates how to capture an image using the OV7670 camera with a Raspberry Pi Pico microcontroller and display the captured image using OpenCV in Python.

Table of Contents

• Overview
• Hardware Setup
• Software Setup
• Usage
• License

Overview

The PicOV7670 project involves capturing an image using the OV7670 camera module connected to a Raspberry Pi Pico and then processing and displaying the captured image using Python and OpenCV.

Hardware Setup

Components

• Raspberry Pi Pico
• OV7670 Camera Module
• Connecting Wires
• Two 3.3V I2C Pull-up Resistors

Wiring Diagram

Power & Ground

• Connect GND of Pico to Camera GND
• Connect 3V3 from Pico to Camera 3V3
• Connect 3V3 from Pico to I2C pull-up resistors (×2)

I2C Connections

• Connect one I2C pull-up resistor to Pico GP8
• Connect the other I2C pull-up resistor to Pico GP9
• Connect Pico GP8 to Camera SDA
• Connect Pico GP9 to Camera SCL

Camera Control Connections

Camera Pin	Pico Pin
VSYNC	GP7
RESET	GP10
CLOCK	GP11
MCLK	GP20
HREF	GP21

Camera Data Connections

Camera Pin	Pico Pin
D0	GP12
D1	GP13
D2	GP14
D3	GP15
D4	GP16
D5	GP17
D6	GP18
D7	GP19

Software Setup

Microcontroller Code

1. Install the required libraries for the microcontroller:

   • adafruit_bus_device
   • adafruit_ov7670

2. Upload the following code to the Raspberry Pi Pico:

import board
import busio
from adafruit_ov7670 import OV7670, OV7670_SIZE_DIV16

def capture_image():
    """
    Captures an image using the OV7670 camera and prints the image data to serial output.
    """
    # Initialize I2C bus
    i2c = busio.I2C(scl=board.GP9, sda=board.GP8)

    # Initialize the OV7670 camera
    cam = OV7670(
        i2c,
        data_pins=[
            board.GP12, board.GP13, board.GP14, board.GP15,
            board.GP16, board.GP17, board.GP18, board.GP19
        ],
        clock=board.GP11,
        vsync=board.GP7,
        href=board.GP21,
        mclk=board.GP20,
        shutdown=None,
        reset=board.GP10,
    )

    # Set camera resolution
    cam.size = OV7670_SIZE_DIV16

    # Create a buffer to store the captured image
    buf = bytearray(25 * cam.width * cam.height)

    # Capture an image
    cam.capture(buf)

    # Print the image data to serial output
    print(buf)

Python Code

1. Install the required Python libraries:

   • numpy
   • opencv-python

2. Save the following code to a Python script (e.g., display_image.py):

import numpy as np
import cv2

# Assuming your image data is stored in a variable called 'image_data'
image_data = bytearray(b'*|ENTER HERE EXTRACTED DATA|*')

# Assuming the image resolution is 200x150
width = 200
height = 150

# Check if the size of the image data matches the expected size
expected_size = width * height
if len(image_data) != expected_size:
    raise ValueError(f"Expected size {expected_size}, but got {len(image_data)}")

# Convert the bytearray to a NumPy array
np_data = np.frombuffer(image_data, dtype=np.uint8)

# Reshape the NumPy array to the image dimensions
image_np = np_data.reshape(height, width)

# Display or save the image as needed using OpenCV
cv2.imshow("Decoded Image", image_np)  # Display the image
cv2.waitKey(0)
cv2.destroyAllWindows()  # Close the window after a key is pressed

Usage

1. Capture an image using the microcontroller code.
2. Copy the printed image data to the image_data variable in the Python script.
3. Run the Python script to display the captured image.

License

This project is licensed under the MIT License.