Implementing HTTP Image Transmission on a Development Board

The RT-Thread Vision Board’s OpenMV firmware supports two modes of HTTP image transmission:

1. STA Mode: The Vision Board acts as a station, connecting to an existing wireless network.
2. AP Mode: The Vision Board creates its own wireless network as the central node, allowing other devices to connect to it.

Hardware Requirements:

• Vision Board: Renesas RA8D1 hardware board (Vision Board)
• Wi-Fi
• A data cable

Software Preparation:

Flash the latest OpenMV firmware from the mainline:

OpenMV Firmware

STA Mode:

1. Open OpenMV IDE.
2. Navigate to File → Examples → WiFi → mjpeg_streamer.py.

• SSID: Enter the name of the Wi-Fi network you want to connect to (only supports 2.4GHz Wi-Fi).
• KEY: Enter the password for the Wi-Fi network.

• Finally, run the script and ensure that the device viewing the image and the Vision Board are on the same network segment (i.e., they can ping each other).
• Once the Vision Board successfully connects to the hotspot, it will display the assigned IP address.

You can also view the IP address and other information in the Vision Board’s serial terminal.

• Copy the IP address into your browser and use port 8080. For example: http://192.168.31.182:8080. You will then be able to view the image data.

AP Mode:

Open OpenMV IDE and navigate to File → Examples → WiFi → mjpeg_streamer_ap.py.

Finally, run the script and connect the device that will be viewing the image to the Wi-Fi hotspot named OPENMV_AP. The password is: 1234567890.

Once connected successfully, a message indicating “No Internet Access” will appear. This is normal, as the Vision Board’s network interface is functioning as an AP device.

At this point, you can access the default address http://192.168.1.1:8080 in your browser to view the image data.

Finally, the tested frame rate for transmitting QQVGA format grayscale images is approximately 25 FPS.