1. Introduction
The DIYmall ESP32S 4 Channel WiFi Bluetooth Relay Module is a versatile control board designed for home automation and IoT projects. It integrates an ESP32-WROOM-32U module, providing both Wi-Fi and Bluetooth connectivity to control four independent relays. This manual provides essential information for setting up, operating, and troubleshooting your relay module.
Video Description: A short video demonstrating the ESP32S 4 Channel WiFi Bluetooth Relay Module and its various components.
2. Package Contents
Please verify that all items are present in your package:
- ESP32S 4 Channel WiFi Bluetooth Relay Module
- USB-to-TTL Serial Adapter
- Jumper Wires
- 2.4G WiFi Antenna
- US Plug Power Adapter (optional, depending on bundle)
- EU Plug Power Adapter (optional, depending on bundle)
Image Description: This image displays the complete kit, including the ESP32S 4-channel relay module, a USB-to-TTL serial adapter, jumper wires, a 2.4G WiFi antenna, and both US and EU power adapters.
3. Specifications
| Feature | Specification |
|---|---|
| Model Number | FZ2707U |
| Input Voltage | 6V 0.750A (Recommended: 9V 1A or 12V 1A if issues occur) |
| Relay Capacity (per relay) | 250Vac/10A, 125Vac/10A, 30VDC/10A |
| Number of Relays | 4 (independently controlled) |
| Wireless Interface | Wi-Fi, Bluetooth |
| Wi-Fi Standard | 2.4G |
| State of Assembly | Almost Ready / Ready-to-Go |
| Compatibility | Others |
| Camera Equipped | No |
| Certification | None |
Image Description: A top-down view of the ESP32S 4-channel relay module, highlighting the ESP32-WROOM-32U chip, four blue relays, power input terminals, and various pin headers.
Image Description: The underside of the ESP32S 4-channel relay module, showing solder pads and the 'Relay32 V2.1' marking.
4. Setup Instructions
4.1 Power Connection
- Connect the appropriate power adapter (US or EU plug) to the module's power input terminal.
- Ensure the power supply provides 6V 0.750A. If the module does not function correctly, try a 9V 1A or 12V 1A power supply.
Image Description: The ESP32S 4-channel relay module connected to a US plug power adapter.
Image Description: The ESP32S 4-channel relay module connected to an EU plug power adapter.
4.2 WiFi Antenna Connection
- Carefully connect the 2.4G WiFi antenna to the U.FL connector on the ESP32S module.
Image Description: The ESP32S 4-channel relay module with the included 2.4G WiFi antenna connected to its U.FL connector.
4.3 Initial Wi-Fi Connection
Upon startup, the module creates a WPA2 protected Wi-Fi access point. You can connect to it using the following credentials:
- Wi-Fi Name (SSID): TEST
- Password: 123456789
4.4 Programming Connection (for advanced users)
To burn new firmware or modify the module's behavior, you will need to connect a USB-to-Serial Port Module. Use jumper wires to connect the module as shown in the diagrams below:
- Relay32 GND to Serial Port Module GND
- Relay32 TXD to Serial Port Module RXD
- Relay32 RXD to Serial Port Module TXD
Image Description: This diagram illustrates how to connect the ESP32S Relay Module to a USB-to-Serial Port Module for programming. Connections shown are: Relay32 GND to Serial Port Module GND, Relay32 TXD to Serial Port Module RXD, and Relay32 RXD to Serial Port Module TXD.
Image Description: An alternative wiring diagram for connecting the ESP32S Relay Module to a USB-to-Serial Port Module for programming, showing different colored wires for clarity. Connections are: Relay32 GND to Serial Port Module GND, Relay32 TXD to Serial Port Module RXD, and Relay32 RXD to Serial Port Module TXD.
5. Operation
The relays can be switched on and off individually via Bluetooth or Wi-Fi connection.
5.1 Wi-Fi Control (Web Server)
The module includes a simple web server that allows control via HTTP GET requests. After connecting to the module's Wi-Fi access point (SSID: TEST, Password: 123456789), you can use a web browser or any application capable of sending HTTP GET requests to control the relays.
- Activate Relay 1:
http://192.168.1.1/h1 - Deactivate Relay 1:
http://192.168.1.1/l1 - Get All Relay States (JSON format):
http://192.168.1.1/j
Replace '1' with '2', '3', or '4' to control other relays.
5.2 Bluetooth Control
A Bluetooth GATT server is created and can be used concurrently with the Wi-Fi access point. You can control the relays using a compatible mobile application.
- iOS App: Search for "DIYMall Relay Control" in the Apple App Store.
- Android App: Please contact the seller for the Android application link.
6. Programming and Advanced Configuration
The module's default firmware operates as a Wi-Fi Access Point (AP) only. For advanced functionalities, such as operating in client mode (connecting to an existing Wi-Fi network) or custom logic, firmware modification is required.
6.1 Firmware Modification
To modify the firmware, you will need a USB-to-Serial Port Module (included in some bundles) and development tools. The process involves burning new firmware onto the ESP32 chip. The seller can provide the firmware if requested.
6.2 Client State Operation
While the default firmware is AP-only, it can be modified to operate in client state. This allows the module to connect to your existing LAN, enabling control over your local network. This requires a firmware change and is recommended for advanced users familiar with ESP32 development.
6.3 WAN Control via Port Forwarding
If the module is configured for client state operation and connected to your LAN, and you set up the relay client as a DMZ (Demilitarized Zone) on your router, it is possible to control it over a Wide Area Network (WAN) using port forwarding. This is an advanced network configuration and requires careful setup to ensure security.
7. User Tips
- Power Supply: If the module does not power on or behaves erratically with the standard 6V 0.750A input, consider using a more robust power supply such as 9V 1A or 12V 1A.
- Firmware Development: For custom applications or client mode functionality, you will need to compile and flash new firmware. Resources for ESP32 development, such as the Espressif ESP-IDF documentation, can be found online. For Windows setup, refer to: Espressif ESP-IDF Windows Setup.
- Community Support: If you encounter difficulties with firmware compilation or advanced programming, consider posting your questions on the Espressif forums. The community is often helpful with development-related queries.
8. Troubleshooting
- Module Not Powering On: Check the power supply. Ensure it meets the 6V 0.750A requirement. If problems persist, try a 9V 1A or 12V 1A power adapter.
- Cannot Connect to Wi-Fi: Verify the Wi-Fi name (SSID: TEST) and password (123456789) are entered correctly. Ensure your device is within range of the module's access point.
- Relays Not Responding: Confirm that the module is powered and connected to Wi-Fi or Bluetooth. Double-check the HTTP GET request syntax or the mobile app commands.
- Firmware Issues: If you have attempted to flash custom firmware and the module is unresponsive, ensure your programming connections are correct (GND, TXD, RXD) and that the firmware compilation process was successful. Refer to Espressif documentation for detailed flashing procedures.
9. Maintenance
- Keep the module in a dry environment, away from moisture and extreme temperatures.
- Avoid exposing the module to static electricity. Handle with care, especially when connecting or disconnecting components.
- Regularly check power connections for secure fit.
- For optimal Wi-Fi performance, ensure the 2.4G antenna is securely attached and positioned away from obstructions.
10. Warranty and Support
For technical support, firmware updates, or specific questions regarding the Android application, please contact the seller directly. Information regarding warranty terms should be available from your point of purchase.
For general ESP32 development questions, the Espressif community forums are an excellent resource.
