ArduCAM × W6300-EVB-Pico2 High-Speed JPEG Streaming Project

1. Project Overview

This project demonstrates a real-time Ethernet-based JPEG streaming system built using the WIZnet Pico (RP2040/RP2350) board combined with the ArduCAM Quick-Bootup 3MP DVP Camera.

Two main components make up the system:

Camera side (Pico): Captures JPEG frames via an 8-bit DVP interface and transmits them over Ethernet by splitting the data into UDP packets.

PC side (Python): Receives packets, reassembles complete frames using header information, and decodes the JPEGs in real time with OpenCV.

Through this project, makers can gain a complete understanding of real-time embedded camera streaming over Ethernet, forming a foundation for IoT vision, robotics, and remote monitoring applications.

[ArduCam X WIZnet Pico UDP Streaming Github Project Link]

🧠 Core Keywords:RP2040 DVP PIO DMA / UDP JPEG Streaming / Frame Reassembly / OpenCV Real-Time Decoding

🧠 Core Keywords:RP2040 DVP PIO DMA / UDP JPEG Streaming / Frame Reassembly / OpenCV Real-Time Decoding

2. Hardware Modules

WIZnet Pico (RP2040 / RP2350)

[WIZnet Pico RP2040 Based Link]

[WIZnet Pico RP2350 Based Link]

Supports both RP2040 and RP2350 (up to 200MHz system clock)

Embedded Ethernet options:

W5100S / W5500 / W6100 — SPI (40MHz)

W6300 — QSPI Quad (37.5MHz)

Fully compatible with Pico SDK 1.5.1

Supports simultaneous use of DVP Camera + Ethernet + SPI Flash + UART

Arducam Quick-Bootup 3MP DVP Camera for IoT

[Arducam Quick-Bootup 3MP DVP Camera for IoT]

💡 With its 300ms instant-on capability and ultra-low power design,this module is ideal for “instant-response IoT vision applications.”

💡 With its 300ms instant-on capability and ultra-low power design,this module is ideal for “instant-response IoT vision applications.”

3. Performance Comparison (Sys Clock 200MHz)

✅ The W6300 QSPI variant delivers smooth HD streaming even in real-time applications.

These values represent typical JPEG-compressed frame sizes and throughput measured under 37.5 MHz QSPI operation on the W6300-EVB-Pico2 board.

4. Pin Mapping (Pico ↔ ArduCAM)

📸 Each PCLK rising edge samples one pixel (8-bit data),while VSYNC HIGH defines the active frame transmission window.

📸 Each PCLK rising edge samples one pixel (8-bit data),while VSYNC HIGH defines the active frame transmission window.

5. JPEG Frame Capture Sequence (on Pico)

① VSYNC ↑ → Frame Start  
② HSYNC ↑ → New Line Start  
③ PCLK ↑ → Sample D0–D7 (8-bit pixel)  
④ DMA stores 32-bit chunks into line buffer  
⑤ HSYNC ↓ → Line End  
⑥ VSYNC ↓ → Frame End

The PIO handles the timing logic, while DMA continuously transfers 32-bit data blocks (512 bytes per line) into RAM.

📥 If the SOI marker (0xFFD8) isn’t detected within the first 4 lines (512B × 4),the system retries until a valid frame is captured.

📥 If the SOI marker (0xFFD8) isn’t detected within the first 4 lines (512B × 4),the system retries until a valid frame is captured.

6. Final Streaming Process (UDP-based Transmission)

Since JPEG frames vary in size (a few KB to tens of KB),a single UDP packet cannot contain the entire image.

Therefore, the Pico splits each frame into ≤1, 400-byte payloads,attaching a small 4-byte header to each.

📡 T ransmission (Pico)

total_packets = (jpeg_size + PAYLOAD_SIZE - 1) / PAYLOAD_SIZE;

for (pkt_id = 0; pkt_id < total_packets; pkt_id++) {
    tx_packet[0] = frame_id;
    tx_packet[1] = pkt_id;
    tx_packet[2] = total_packets;
    tx_packet[3] = (pkt_id == total_packets - 1) ? 0x01 : 0x00;

    memcpy(tx_packet + 4, jpeg_data + offset, chunk_size);
    sendto(socket, tx_packet, chunk_size + 4, destip, destport);
}

🧩 R eassembly (Python)

On the receiver side, each packet is reassembled based on Frame ID and Packet ID.The Assembler class reconstructs full JPEG frames as follows:

fid, pid, tot = pkt[0], pkt[1], pkt[2]
self.buf.setdefault(fid, {})[pid] = pkt[4:]
if len(self.buf[fid]) == tot:
    data = b"".join(self.buf[fid][i] for i in range(tot))
    return data  # Complete JPEG frame restored

OpenCV then decodes and displays the frame in real time.

🖥️ Even with UDP transport, this design achieves lossless frame assembly through intelligent ID-based reordering.

🖥️ Even with UDP transport, this design achieves lossless frame assembly through intelligent ID-based reordering.

7. How to Run( Execution Guide )

Follow these steps to build, flash, and run the ArduCAM × WIZnet Pico JPEG Streaming demo.

① Select Your Board in the Top-Level CMakeLists.txt

Open the project’s root CMakeLists.txt.

• Open the project’s root CMakeLists.txt.

Uncomment your target board (for example, W6300-EVB-PICO2) and comment out the others.

• Uncomment your target board (for example, W6300-EVB-PICO2) and comment out the others.

This ensures the correct pin mapping, SPI/QSPI mode, and driver are used.

• This ensures the correct pin mapping, SPI/QSPI mode, and driver are used.

Example:

# set(BOARD_NAME "W5100S-EVB-PICO")
# set(BOARD_NAME "W5500-EVB-PICO")
# set(BOARD_NAME "W6100-EVB-PICO")
set(BOARD_NAME "W6300-EVB-PICO2")  # ← active target board

Then, open
example/WIZnet_ArduCAMMega_UDP_Streaming/main.c
and modify the following parameters as needed:

IP address / Gateway / Subnet

• IP address / Gateway / Subnet

UDP port number (default: 5000)

• UDP port number (default: 5000)

System clock frequency (default: 200 MHz)

• System clock frequency (default: 200 MHz)

Save the file after editing.

② Build the Firmware

Open a terminal in the project directory and run:

mkdir build
cd build
cmake ..
make -j4

This will generate the compiled firmware file:

build/example/WIZnet_ArduCAMMega_UDP_Streaming/main.uf2

③ Flash the Firmware to the Pico

Connect your WIZnet Pico (RP2040/RP2350) via USB while holding the BOOTSEL button.

• Connect your WIZnet Pico (RP2040/RP2350) via USB while holding the BOOTSEL button.

The board will appear as a USB drive (e.g., RPI-RP2).

• The board will appear as a USB drive (e.g., RPI-RP2).

Copy the generated main.uf2 file into this drive.

• Copy the generated main.uf2 file into this drive.

The board will automatically reboot and start running the streaming firmware.

• The board will automatically reboot and start running the streaming firmware.

④ Run the Python GUI on Your PC

Move to the example directory and run the GUI streaming viewer:

cd example/WIZnet_ArduCAMMega_UDP_Streaming
python.exe jpeg_stream_gui.py

This GUI will:

Connect to the Pico’s UDP streaming server

• Connect to the Pico’s UDP streaming server

Reassemble incoming JPEG packets

• Reassemble incoming JPEG packets

Decode and display them in real time using OpenCV

• Decode and display them in real time using OpenCV

8. Key Takeaways