How to Use TTL USR-TCP232-T2: Examples, Pinouts, and Specs

The TTL USR-TCP232-T2 is a compact and efficient serial-to-TCP/IP converter module manufactured by Arduino. It enables seamless integration of serial devices into Ethernet networks, allowing for remote monitoring, control, and data exchange. This module supports a wide range of baud rates and can be configured through a user-friendly web interface. Its small size and versatile functionality make it ideal for applications such as industrial automation, IoT devices, and remote data acquisition systems.

• Industrial automation and control systems
• IoT (Internet of Things) devices
• Remote monitoring and data logging
• Home automation systems
• Serial device networking (e.g., RS232/TTL devices)

1. Power Supply: Connect the VCC pin to a 3.3V DC power source and the GND pin to ground.
2. Serial Connection: Connect the TXD and RXD pins to the corresponding RX and TX pins of your microcontroller or serial device.
3. Ethernet Connection: Connect the Ethernet pins (ETH_TX+, ETH_TX-, ETH_RX+, ETH_RX-) to an RJ45 Ethernet connector for network communication.
4. Reset: Optionally, connect the RST pin to a push-button or microcontroller GPIO for resetting the module.
5. Configuration:
   • Access the module's web interface by connecting it to a network and entering its default IP address in a web browser.
   • Alternatively, configure the module using serial AT commands via the TXD and RXD pins.

• Ensure the power supply voltage is strictly 3.3V to avoid damaging the module.
• Use proper Ethernet cabling and connectors to ensure reliable network communication.
• Configure the baud rate and network settings to match your application requirements.
• Avoid placing the module near high-frequency noise sources to maintain signal integrity.

Below is an example of how to connect and use the TTL USR-TCP232-T2 with an Arduino UNO for serial-to-Ethernet communication.

#include <SoftwareSerial.h>

// Define RX and TX pins for SoftwareSerial
SoftwareSerial mySerial(10, 11); // RX = Pin 10, TX = Pin 11

void setup() {
  // Initialize serial communication with the TTL module
  mySerial.begin(9600); // Set baud rate to match the module's configuration
  Serial.begin(9600);   // For debugging via Serial Monitor

  // Send a test message to the TTL module
  mySerial.println("Hello, TTL USR-TCP232-T2!");
  Serial.println("Message sent to TTL module.");
}

void loop() {
  // Check if data is available from the TTL module
  if (mySerial.available()) {
    String data = mySerial.readString(); // Read incoming data
    Serial.print("Received from TTL module: ");
    Serial.println(data); // Print data to Serial Monitor
  }

  // Check if data is available from the Serial Monitor
  if (Serial.available()) {
    String data = Serial.readString(); // Read user input
    mySerial.println(data); // Send data to the TTL module
  }
}

1. No Response from the Module:

   • Ensure the module is powered with 3.3V DC.
   • Verify the TXD and RXD connections are correct and not swapped.
   • Check the baud rate configuration on both the module and the microcontroller.

2. Ethernet Connection Fails:

   • Confirm the Ethernet cable is properly connected and functional.
   • Verify the network settings (IP address, subnet mask, gateway) are correctly configured.
   • Ensure the module is not blocked by a firewall or network restrictions.

3. Module Does Not Reset:

   • Check if the RST pin is properly connected to ground for a brief moment.
   • Ensure the reset signal is not held low for too long.

Q1: Can the module work with 5V logic levels?
A1: No, the TTL USR-TCP232-T2 operates at 3.3V logic levels. Use a level shifter if interfacing with 5V devices.

Q2: How do I restore the module to factory settings?
A2: Hold the RST pin low for 5 seconds while powering on the module. This will reset all settings to default.

Q3: What is the default IP address of the module?
A3: The default IP address is typically 192.168.0.7. Refer to the module's datasheet for confirmation.

Q4: Can I use this module for wireless communication?
A4: No, the TTL USR-TCP232-T2 is designed for wired Ethernet communication only.