Appendix

Modules

Camera-1 (Node-Matrix)

Camera-M (Node-Matrix)

ESP32-CAM (Ai-Thinker)

GPIO12 Port

GPIO12 of the ESP32 chip is a Strapping pin. During system reset/power-up, the level of the Strapping pin will change the system boot mode or configuration. The level of the GPIO12 pin determines the output voltage of the VDD_SDIO pin during reset. As described in the ESP32 datasheet, if GPIO12 is low during system reset, VDD_SDIO outputs 3.3V; if it is high, VDD_SDIO outputs 1.8V.

If the module uses VDD_SDIO output as the power supply for external Flash or PSRAM chips, an incorrect GPIO12 level will cause the chip to malfunction. For example, the GPIO12 of the ESP32-CAM (Ai-Thinker) module must remain low during reset. Therefore, GPIO12 cannot be directly used as an I2C pin (with a pull-up resistor).

By modifying the ESP32 chip's eFuse bits, you can set a fixed output voltage for VDD_SDIO, making GPIO12 a normal GPIO port. Modifying the eFuse bits requires using esptool. See the official documentation for installation:

https://docs.espressif.com/projects/esptool/en/latest/esp32/

Steps to modify the eFuse bits:

1. Connect the module via USB serial port, reset the module to bootloader mode (keep GPIO0 low during reset).

2. Check the current eFuse data using the espefuse.py command (replace COMx with the actual serial port):

   espefuse.py --port COMx summary

   

   VDD_SDIO determined by GPIO12

3. Set VDD_SDIO fixed output to 3.3V:

   espefuse.py --port COMx set_flash_voltage 3.3V

   

   set_flash_voltage 3.3V

   espefuse.py will prompt you to enter BURN (uppercase) for confirmation before modifying the eFuse.

4. After successful modification, Check the eFuse data again (summary):

   

   VDD_SDIO set to 3.3V by efuse

eFuse bits cannot be recovered after modification, please operate with caution.

FileZilla Server

FileZilla Server is a free FTP/FTPS server for the Windows platform.

Download address: https://filezilla-project.org

Installation and configuration:

1. Download and run the installer. In the Server settings interface during the installation process, select the service startup method. For testing purposes, you can choose manual mode, and on the next page, select the console to start manually.

   

   Service startup method

2. After completing the installation, the FileZilla Server program group in the start menu is shown below. Start/Stop FileZilla Server need to be run as administrator (right-click > More > Run as administrator).

   

   FileZilla Server program group

3. Run Start FileZilla Server as administrator. Then run Administer FileZilla Server to open the console and connect to FileZilla Server.

   

   Connect to FileZilla Server

4. In the console interface, click the menu Server > Configure... to open the Settings for server dialog. Configure the settings as follows:

   

   FTP Server Settings

   1. Select the page: Rights management > Users
   2. Click the Add button to add an FTP user (node).
   3. Select the newly added user, and set the FTP access password.
   4. Add the FTP local path for the user.
   5. Set read and write permissions for the path.

After completing the settings, please check the Windows firewall rules: Allow TCP 21 inbound connections and TCP 20 outbound connections.

Save Video Stream

The ffmpeg tool can encode the MJPEG video stream output by Node-Camera into H.264 format for saving.

1. Download the ffmpeg tool from ffmpeg.org. Here, only ffmpeg.exe is needed, ensure it is accessible from the command line. (Add to the Path environment variable or copy ffmpeg.exe to the working directory)

2. Execute the following command in the working directory (replace ${host} with the actual IP):

   ffmpeg.exe -f mjpeg -use_wallclock_as_timestamps 1 -i http://${host}:81/stream -c:v libx264 -crf 23 node.avi

   The above command saves the video stream as node.avi. The option -crf adjusts the video compression quality, with a value range of 0~51 (smaller values mean higher quality).

ffmpeg reference: https://ffmpeg.org/ffmpeg.html

Error Codes

System error codes reference:

Code	Description
0x50001	ERR_UNAUTHORIZED
0x50002	ERR_INVALID_SETTINGS
0x50003	ERR_INVALID_PRESETS
0x50004	ERR_BAD_DATA
0x50005	ERR_BUF_INSUFFICIENT
0x50006	ERR_CRC_FAILED
0x50007	ERR_BAD_REQUEST
0x50008	ERR_INTERNAL_ERROR
0x50009	ERR_SESSION_EXCEEDED
0x5000A	ERR_INVALID_SOCKET
0x5000B	ERR_SD_DISABLED
0x5000C	ERR_SD_NOT_INIT
0x5000D	ERR_SD_FS
0x5000E	ERR_NO_FILE
0x5000F	ERR_NO_PATH
0x50010	ERR_ACT_NOT_INIT
0x50011	ERR_ACT_QUEUE_BUSY
0x50012	ERR_CMD_DISABLED
0x50013	ERR_CMD_UNDEFINED
0x50014	ERR_CMD_BAD_PARAM
0x50015	ERR_INVALID_IO
0x50016	ERR_INVALID_CHANNEL
0x50017	ERR_I2C_NOT_CONFIGURED
0x50018	ERR_INVALID_DEVICE
0x50019	ERR_INVALID_ACTUATOR
0x5001A	ERR_DUTY_EXCEEDED
0x5001B	ERR_SERVO_NOT_INIT
0x5001C	ERR_SERVO_END_POINT