How to Use Waveshare TTL-ETH: Examples, Pinouts, and Specs

The Waveshare TTL-ETH (Part ID: 24276) is a TTL to Ethernet module designed to facilitate serial communication over an Ethernet network. This module enables microcontrollers and other devices to connect to the internet or a local network with ease. It is compact, reliable, and ideal for applications requiring Ethernet connectivity without the complexity of implementing a full Ethernet stack.

• IoT (Internet of Things) devices requiring Ethernet connectivity
• Remote monitoring and control systems
• Industrial automation and data acquisition
• Serial-to-Ethernet communication for legacy devices
• Home automation systems

The following table outlines the key technical details of the Waveshare TTL-ETH module:

The Waveshare TTL-ETH module has a 2x5 pin header for interfacing. The pin configuration is as follows:

1. Power Supply: Connect the VCC pin to a 3.3V or 5V power source and the GND pin to ground.
2. UART Communication: Connect the TXD and RXD pins to the UART pins of your microcontroller (e.g., Arduino, Raspberry Pi).
3. Ethernet Connection: Plug an Ethernet cable into the RJ45 port of the module.
4. Configuration Mode: To enter configuration mode, pull the CFG pin low during power-up. This allows you to set parameters such as IP address, baud rate, and communication mode.
5. Normal Operation: For normal operation, leave the CFG pin unconnected or pull it high.

• Ensure the module is powered with the correct voltage (3.3V or 5V) to avoid damage.
• Use a level shifter if your microcontroller operates at 1.8V or 2.5V logic levels.
• Configure the module's network settings (e.g., static IP or DHCP) using the provided configuration software or AT commands.
• Use shielded Ethernet cables in environments with high electromagnetic interference (EMI).
• Avoid long UART cables to minimize signal degradation.

Below is an example of how to use the Waveshare TTL-ETH module with an Arduino UNO to send data over Ethernet.

• VCC → 5V on Arduino
• GND → GND on Arduino
• TXD → Pin 10 on Arduino (RX)
• RXD → Pin 11 on Arduino (TX)
• CFG → Leave unconnected for normal operation

#include <SoftwareSerial.h>

// Define RX and TX pins for software serial communication
SoftwareSerial ethSerial(10, 11); // RX, TX

void setup() {
  // Start serial communication with the module
  ethSerial.begin(9600); // Default baud rate for TTL-ETH module
  Serial.begin(9600);    // For debugging via Serial Monitor

  Serial.println("Initializing Waveshare TTL-ETH module...");
  delay(1000);

  // Example: Send a test message to the Ethernet module
  ethSerial.println("Hello, Ethernet!");
  Serial.println("Message sent to TTL-ETH module.");
}

void loop() {
  // Check if data is received from the Ethernet module
  if (ethSerial.available()) {
    String receivedData = ethSerial.readString();
    Serial.print("Received from TTL-ETH: ");
    Serial.println(receivedData);
  }

  // Check if data is sent from the Serial Monitor
  if (Serial.available()) {
    String userInput = Serial.readString();
    ethSerial.println(userInput); // Send user input to the Ethernet module
    Serial.println("Message sent to TTL-ETH module.");
  }
}

1. No Ethernet Connectivity

   • Ensure the Ethernet cable is securely connected to the module and the router/switch.
   • Verify the module's IP address and network settings using the configuration software.

2. UART Communication Fails

   • Check the baud rate settings on both the module and the microcontroller.
   • Ensure the TXD and RXD pins are correctly connected (crossed: TXD to RX, RXD to TX).

3. Module Not Responding

   • Verify the power supply voltage and current are within the specified range.
   • Reset the module by pulling the RESET pin low momentarily.

4. Configuration Mode Not Working

   • Ensure the CFG pin is pulled low during power-up to enter configuration mode.
   • Use the manufacturer's configuration software to verify and update settings.

Q1: Can the TTL-ETH module work with 1.8V logic microcontrollers?
A1: No, the module operates at 3.3V or 5V logic levels. Use a level shifter for compatibility.

Q2: How do I update the firmware of the TTL-ETH module?
A2: Firmware updates can be performed using the manufacturer's software and a UART-to-USB adapter.

Q3: Can I use the module with DHCP?
A3: Yes, the module supports both static IP and DHCP. Configure this setting in the configuration mode.

Q4: What is the maximum cable length for Ethernet?
A4: The maximum recommended length for Ethernet cables is 100 meters (328 feet).