Demo description

• This example implements the control of 8 relays on and off through WiFi, Bluetooth, network port and RS485. The AP mode of WiFi is enabled in this example

Precautions

• Can be flashed directly
• The web page can only be accessed by connecting to the device's WIFI, or if connected to a network cable, by accessing the network port IP within the internal network

Code analysis

• Relay_Analysis(): This function is mainly used to analyze received data, perform corresponding relay control operations based on the data content, and output corresponding status prompt information.
  • Parameter analysis
    • uint8_t *buf: A pointer to an unsigned 8-bit integer array, which is supposed to store the received data, and the function determines the content of the command based on the value of the first element (buf[0]) of the array.
    • uint8_t Mode_Flag: The mode flag is used to represent the data source, and the corresponding data source prompt information (such as Bluetooth data, Wi-Fi data, or RS485 data) is output by judging this flag, and different relay operations are performed according to different commands.
  • Logical flow
    • First output the corresponding data source prompt message according to the value of Mode_Flag.
    • Then use the switch statement to perform different operations based on the value of buf[0]:
      • For the cases from CH1 to CH8, the digitalToggle function is used to switch the level states of the corresponding EXIO pins (such as GPIO_PIN_CH1, etc.), and the corresponding elements of the Relay_Flag array are updated to record the change in relay status. The Buzzer_PWM function is called to control the buzzer, and the corresponding on or off prompt information is output according to the final state of the relay.
      • For the ALL_ON command, set all GPIO pins (corresponding to 8 channel relays) to high level (on state), use the memset function to set all elements of the Relay_Flag array to 1, indicating that all relays are turned on, output all relay ON prompt information, and control the buzzer.
      • For the ALL_OFF command, set all relevant GPIO pins to low level (off state) similarly, update the Relay_Flag array elements to 0, output a message that all relays are turned off and control the buzzer, and perform two additional buzzer control operations (with a delay in between).
      • If the value of buf[0] does not belong to the above command cases, a prompt message for non-instruction data is output.

• WIFI_Init (): Configure the device as a Wi-Fi access point (AP), set up a Web server, and set up request processing functions corresponding to different paths to implement related network functions and device control functions, and give corresponding status prompts.
  • AP creation
    • First set the Wi-Fi mode to WIFI_AP, and then attempt to create a soft AP through WiFi.softAP(ssid, password). If it fails, it will loop through prompt and retry until it succeeds
  • Parameter configuration and prompts
    • After successfully creating the AP, give a prompt with RGB light (green light on for 1 second)
  • IP address display
    • Obtain and format the IP address of the soft AP, store it in ipStr and output it for easy network address recognition
  • Web server setting
    • Set up corresponding request handling functions (such as handleRoot, handleGetData, etc.) for multiple paths (such as "/", "/getData", etc.) through server.on, each function should be defined elsewhere for different functional operations like returning pages, getting data, controlling switches etc.
    • Finally call server.begin() to start the Web server and output a startup prompt message.

Demo description

• This example implements the control of 8 relays on and off through WiFi, Bluetooth, and RS485. The STA mode of WiFi is enabled in this example

Precautions

• Need to modify the WIFI to be connected
• The Web page only supports controlling the device and this product to be used under the same network, if you use the mobile phone control, you need to turn off the mobile network

Code analysis

• WIFI_Init (): Connect the device to a specified Wi-Fi network in station (STA) mode. If the connection is successful, it will perform subsequent network-related configurations (such as obtaining an IP address, starting a Web server, and registering callback functions, etc.). If the connection fails, it will give a corresponding prompt and set the connection status flag. The process also provides visual connection status indicators through an RGB light
  • Attempt to connect to Wi-Fi network:
    • First set Wi-Fi to WIFI_STA mode and enable sleep mode, then start connecting to the specified network. In the cyclic wait of unsuccessful connection, a point is output as a prompt every half second, and the RGB light briefly turns red on every even number of attempts (except the first attempt). If every 10 attempts fail, the connection is disconnected and reconnected. If the number of attempts exceeds 22, the connection is considered a failure and the loop is exited.
  • Operations after successful connection:
    • If the number of connection attempts is less than 23 (i.e. successful connection), set WIFI_Connection to 1, light up the green light for 1 second to indicate success, and then obtain and display the local IP address. Next, register callback functions corresponding to multiple paths for the web server (such as root path, data retrieval, control of different switches, etc.), and finally start the server and output startup prompt, so that the device can receive corresponding control through the web page.
  • Operations after connection failure:
    • If the number of attempts is greater than or equal to 23 (connection failure), set WIFI_Connection to 0, output a prompt to inform that the device can be controlled through Bluetooth debugging assistant, and light a red light to indicate a connection failure status

Demo description

• This example controls 8 relays through MQTT, Bluetooth, and RS485 communication methods. It uses ESP32 as the main control unit, supports Wi-Fi and Bluetooth connections, and provides remote control based on the MQTT protocol

Precautions

• Need to modify the WIFI to be connected
• Must create the device in Waveshare Cloud

Code analysis

• Relay_Analysis(): Receive data from different communication sources and perform corresponding relay control operations
  • Data Delivery: Commands (such as CH1, ALL_ON etc.) are sent to the device via Bluetooth, Wi-Fi, or RS485. The device parses and executes the corresponding operation after receiving a command. For example, when the command CH1 is received, the function will switch the state of relay 1
  • Data Feedback: The execution of control commands is printed to the serial monitor via printf (e.g., relay status update: "Relay CH1 on") and fed back via the buzzer Buzzer_PWM). This allows users to see real-time status updates
  • Communication Protocol
    • Bluetooth: Wireless communication with mobile phones or other devices through Bluetooth modules, and the device controls the relay after receiving the command
    • MQTT: Connect to the MQTT server via Wi-Fi, and the device subscribes to a specific topic (such as relay control commands). When a new command is issued, the device receives the message via MQTT and performs relay control
    • RS485: The device receives RS485 commands through the serial port and switches the relay status according to the commands

• setup ()
  • Initialize the various modules required for the system, including serial port, GPIO, RTC, Bluetooth and Wi-Fi (MQTT)
    • Call Bluetooth_Init(), and the device can establish connections with other Bluetooth devices and receive control commands
    • With MQTT_Init(), the device will connect to the Wi-Fi network and be able to communicate with remote servers through the MQTT protocol
  • Time Synchronization
    • If the system is connected to Wi Fi and RTC is enabled, the Acquisition_time() function will synchronize the current time to RTC through the network, ensuring that the device has accurate system time
  • Data Upload and Delivery
    • Upload: When the device successfully connects to Wi Fi or Bluetooth, it can upload device status information or sensor data (such as temperature, humidity) through MQTT. These data will be sent to the MQTT server regularly for other systems or users to view
    • Delivery: The device receives a control command from the MQTT server and performs corresponding actions, such as switching relays on and off or changing configurations

RS485 Control

• Jump to RS485 Control Tutorial

Bluetooth Control

• Jump to Bluetooth Control Tutorial

Waveshare Cloud Control

• Jump to Waveshare Cloud Control

Demo description

• This example is a collection of RS485 interface control, Bluetooth control, Web page control (near distance), and Waveshare cloud control (long distance).

Precautions

• Need to modify the WIFI to be connected
• The Web page only supports controlling the device and this product to be used under the same network, if you use the mobile phone control, you need to turn off the mobile network
• Must create the device in Waveshare Cloud

RS485 Control

• Jump to RS485 Control Tutorial

Bluetooth Control

• Jump to Bluetooth Control Tutorial

Web Page Control

• Jump to Web Control Tutorial, this example is in AP mode

Waveshare Cloud Control

• Jump to Waveshare Cloud Control