Sensor Node Operation Guide¶

1 PREPARATION¶

1.1 MQTT Command Sender¶

(1) Computer:¶

It is recommended to install MQTTX for publishing MQTT commands. Download Link

After installation, first establish a connection with the server as follows:

Then subscribe to the topic "ArduinoNode/node"

Once completed, you will start receiving messages published by various nodes.

iOS users are recommended to use MyMQTT.

1.2 Sensor Network¶

• It is recommended to charge the batteries before use.

• Ensure all nodes are securely connected and the SD card is properly inserted.

• It is advisable to power on the leaf nodes first, followed by the gateway node.

2 DEPLOY THE SENSOR NETWORK¶

Deploy the sensor nodes in the areas that need monitoring, ideally ensuring that the distance between leaf nodes and the gateway does not exceed 25 meters.

3 ISSUE COLLECTION COMMANDS¶

• First, ensure that the connection to the server is active.

• Enter the topic for publishing commands: "ArduinoNode/server"

• Input the command content according to your sampling needs and the command descriptions.

Appendix - ArduinoNode Command Set¶

A. Command Rules¶

• All commands are strings sent via MQTT or RF channels.

• Time-related commands must ensure that the scheduled time is later than the current time, with at least 60 seconds reserved for time synchronization (otherwise, the command will be rejected).

• Sampling frequency, duration, and other parameters must be integers, with units in Hz and seconds, respectively.

• File retrieval commands must specify the filename (excluding the extension).

B. Command List and Examples¶

Basic Commands¶

Scheduled / Fixed-Time Sensing Commands¶

• Scheduled Sensing (delay in seconds, sampling frequency, duration) Format: CMD_SFN_delay_frequencyHz_durationS Example: CMD_SFN_120_10Hz_60s

• Fixed-Time Sensing (specific time, sampling frequency, duration) Format: CMD_SENSING_YYYY-MM-DD_HH:MM:SS_frequencyHz_durationS Example: CMD_SENSING_2025-09-11_14:30:00_10Hz_60s

Data Retrieval Command¶

• Data Retrieval (file name without extension) Format: CMD_RETRIEVAL_filename Example: CMD_RETRIEVAL_20250911_143000

C. Errors & Feedback¶

• If the command format is incorrect, time is invalid, or parameters are unreasonable, you will receive error feedback.
• The device will also indicate error status via red LED.

D. Additional Notes¶

For extended commands or detailed parameter instructions, please refer to the source code or contact the developer.

Appendix - LED Status Indicators¶