DORHEA ESP32 WiFi 4 Channel Relay Module Instruction Manual

1. Product Overview

The DORHEA ESP32 WiFi 4 Channel Relay Module is a versatile development board designed for smart home and wireless control applications. It integrates the robust ESP32-WROOM-32E module, offering WiFi connectivity and a large 4MByte Flash memory. The module features four independent 5V relays, capable of switching various loads. It supports flexible power input options, including AC220V and DC5-30V, and is compatible with the Arduino IDE for easy programming and development.

Figure 1: Front and back view of the ESP32 WiFi 4 Channel Relay Module.

2. Features

• Integrated ESP32-WROOM-32E WiFi module with 4MByte Flash.
• Flexible power supply: Supports AC220V or DC5-30V input.
• Four 5V relays with output switch signals, suitable for controlling loads up to AC250V/DC30V.
• Includes an RST reset button and a programmable button for user interaction.
• I/O ports and UART program download port are exposed for secondary development.
• Features 1 programmable LED and individual relay indicator LEDs.

Figure 2: Detailed views of key components on the module, including the ESP32 chip, relays, and power input section.

3. Package Contents

The package includes the following items:

• 1 x AC/DC Power Supply ESP32 Four-Way Relay Module
• 2 x 10 Double Row Pin Headers
• 1 x 6 Single Row Pin Header
• 1 x Single Line Cap

Figure 3: The ESP32 relay module along with the included pin headers for connectivity.

4. Setup Instructions

Follow these steps to set up your ESP32 WiFi 4 Channel Relay Module:

4.1. Component Identification and Pinout

Before connecting, familiarize yourself with the module's components and pin assignments. Refer to the diagram below for a clear understanding of each terminal and indicator.

Figure 4: Labeled diagram of the module's connections and features.

• AC 220V Power Supply: Connect your AC 220V power source here.
• DC 7-30V Power Supply: Connect your DC 7-30V power source here.
• GND: Ground connection for DC power.
• 5V Power Supply: 5V output for external components.
• Relay Indicator Light: LEDs that illuminate when the corresponding relay is active.
• Power Indicator Light: Indicates the module is powered on.
• Programmable LED: A user-controllable LED.
• ESP-32E: The main ESP32-WROOM-32E module.
• Reset Button: Resets the ESP32 module.
• Relay Connections (NO, COM, NC): Each of the four relays has Normally Open (NO), Common (COM), and Normally Closed (NC) terminals for connecting loads.

4.2. Power Supply Connection

Choose one of the following power supply methods:

• AC Power: Connect AC 220V to the designated AC 220V terminals (L and N).
• DC Power: Connect DC 7-30V to the DC 7-30V terminals, ensuring correct polarity (positive to VCC, negative to GND).

Caution: Ensure only one power source is connected at a time. Incorrect wiring can damage the module or connected devices.

4.3. Connecting Loads to Relays

Each relay provides three terminals: Normally Open (NO), Common (COM), and Normally Closed (NC). To control a load:

• For a load that should be OFF when the relay is inactive and ON when active, connect one side of the load to the COM terminal and the other side to the NO terminal.
• For a load that should be ON when the relay is inactive and OFF when active, connect one side of the load to the COM terminal and the other side to the NC terminal.

Warning: Always ensure the load's voltage and current ratings are within the relay's specifications (AC250V/DC30V, 10A) to prevent damage or hazards.

4.4. Programming the Module

The module can be programmed using the Arduino IDE. You will need a USB to TTL adapter to connect the module's UART program download port to your computer. The GPIO pins for the relays and programmable LED are as follows:

• Relay 1: GPIO32
• Relay 2: GPIO33
• Relay 3: GPIO25
• Relay 4: GPIO26
• Programmable LED: GPIO23

After initial programming via UART, Over-The-Air (OTA) updates can be configured for wireless code uploads.

5. Operating Instructions

Once programmed, the ESP32 module will execute the uploaded code to control the relays and other functionalities. The relay indicator lights will show the current state of each relay (ON/OFF).

• Wireless Control: Utilize the ESP32's WiFi capabilities to integrate the module into your smart home network. This allows for remote control of connected devices via a smartphone app, web interface, or home automation platform.
• Manual Control: The programmable button can be configured in your code to trigger specific actions, such as toggling a relay or changing modes.

6. Maintenance

To ensure the longevity and reliable operation of your module, follow these maintenance guidelines:

• Keep Dry: Protect the module from moisture and humidity to prevent short circuits and corrosion.
• Cleanliness: Keep the board free from dust and debris. Use a soft, dry brush or compressed air for cleaning. Avoid liquid cleaners.
• Temperature: Operate the module within its specified temperature range. Avoid extreme heat or cold.
• Handle with Care: Avoid dropping or subjecting the module to physical shock. When handling, minimize contact with electronic components to prevent electrostatic discharge.

7. Troubleshooting

If you encounter issues with your module, consider the following troubleshooting steps:

• No Power Indicator Light:
  • Verify the power supply is correctly connected and providing the specified voltage (AC220V or DC5-30V).
  • Check for loose connections or damaged wires.
• Relay Not Switching:
  • Ensure your code is correctly configured to activate the desired GPIO pin for the relay (GPIO32, GPIO33, GPIO25, GPIO26).
  • Check the load connections (NO, COM, NC) for proper wiring.
  • Verify the load's power requirements are within the relay's capacity.
• WiFi Connectivity Issues:
  • Confirm the WiFi credentials (SSID and password) in your ESP32 code are correct.
  • Ensure the module is within range of your WiFi network.
  • Check for any firewall or router settings that might be blocking the connection.
• Programming Upload Failure:
  • Ensure the correct board and port are selected in the Arduino IDE.
  • Verify the USB to TTL adapter is functioning correctly and its drivers are installed.
  • Check the wiring between the module's UART port and the USB to TTL adapter.

8. Specifications

Figure 5: Module dimensions for planning and integration.

9. Warranty and Support

DORHEA products are designed for reliability and performance. For any technical assistance or inquiries regarding your ESP32 WiFi 4 Channel Relay Module, please refer to the seller's support channels on the platform of purchase. Keep your purchase receipt for warranty claims, if applicable.