How To Get A Serial Terminal Emulator In Linux To Ignore RTS & DTR?

Mar 1, 2025 by ADMIN 68 views

Introduction

When working with serial communication devices, such as the ESP8266 module, it's often necessary to use a serial terminal emulator to interact with the device. However, by default, most serial terminal emulators in Linux send RTS (Request To Send) and DTR (Data Terminal Ready) signals to the device, which can cause issues with certain devices. In this article, we'll explore how to get a serial terminal emulator in Linux to ignore RTS & DTR signals.

Understanding RTS & DTR Signals

Before we dive into the solution, let's quickly understand what RTS and DTR signals are. RTS is a signal sent by the terminal to the device to indicate that it's ready to send data. DTR, on the other hand, is a signal sent by the terminal to the device to indicate that it's ready to receive data. These signals are used to control the flow of data between the terminal and the device.

The Problem with RTS & DTR Signals

The problem with RTS and DTR signals is that some devices, like the ESP8266 module, can be sensitive to these signals. When the terminal sends RTS or DTR signals to the device, it can cause the device to behave erratically or even crash. This can make it difficult to interact with the device using a serial terminal emulator.

Solution: Using Minicom to Ignore RTS & DTR Signals

One solution to this problem is to use the Minicom terminal emulator, which allows you to ignore RTS and DTR signals. Here's how to do it:

Step 1: Install Minicom

First, you need to install Minicom on your Linux system. You can do this by running the following command:

sudo apt-get install minicom

Step 2: Configure Minicom

Once Minicom is installed, you need to configure it to ignore RTS and DTR signals. To do this, follow these steps:

Open Minicom by running the following command:

minicom -s

In the Minicom configuration menu, select "Serial port setup" and then select the serial port that you're using to connect to the device.
In the "Serial port setup" menu, select "Hardware flow control" and set it to "No".
Save the changes and exit the configuration menu.

Step 3: Connect to the Device

Now that Minicom is configured to ignore RTS and DTR signals, you can connect to the device using the following command:

minicom -D /dev/ttyUSB0

Replace /dev/ttyUSB0 with the actual serial port that you're using to connect to the device.

Alternative Solution: Using Screen to Ignore RTS & DTR Signals

Another solution to this problem is to use the Screen terminal emulator, which also allows you to ignore RTS and DTR signals. Here's how to do it:

Step 1: Install Screen

First, you need to install Screen on your Linux system. You can do this by running the following command:

sudo apt-get install screen

Step 2: Configure Screen

Once Screen is installed, you need to configure it to ignore RTS and DTR signals. To do this, follow these steps:

Open Screen by running the following command:

screen -D -m /dev/ttyUSB0

Replace /dev/ttyUSB0 with the actual serial port that you're using to connect to the device. 2. In the Screen menu, select "Serial" and then select the serial port that you're using to connect to the device. 3. In the "Serial" menu, select "Hardware flow control" and set it to "No". 4. Save the changes and exit the menu.

Conclusion

In this article, we've explored how to get a serial terminal emulator in Linux to ignore RTS & DTR signals. We've covered two solutions: using Minicom and using Screen. Both solutions allow you to ignore RTS and DTR signals, making it easier to interact with devices that are sensitive to these signals. By following the steps outlined in this article, you should be able to successfully use a serial terminal emulator in Linux to interact with your device.

Additional Tips and Tricks

Here are some additional tips and tricks that you may find useful when working with serial terminal emulators in Linux:

Use the correct serial port: Make sure that you're using the correct serial port to connect to the device. You can do this by running the dmesg command to see which serial port the device is connected to.
Set the baud rate correctly: Make sure that you're setting the baud rate correctly for the device. You can do this by running the stty command to set the baud rate.
Use the correct terminal settings: Make sure that you're using the correct terminal settings for the device. You can do this by running the stty command to set the terminal settings.

Troubleshooting Tips

Here are some troubleshooting tips that you may find useful when working with serial terminal emulators in Linux:

Check the serial port: Make sure that the serial port is working correctly. You can do this by running the dmesg command to see if the serial port is being recognized.
Check the baud rate: Make sure that the baud rate is set correctly for the device. You can do this by running the stty command to set the baud rate.
Check the terminal settings: Make sure that the terminal settings are set correctly for the device. You can do this by running the stty command to set the terminal settings.

Conclusion

Q: What is a serial terminal emulator?

A: A serial terminal emulator is a software program that allows you to interact with a serial device, such as a modem or a microcontroller, using a terminal interface.

Q: Why do I need to use a serial terminal emulator?

A: You need to use a serial terminal emulator to interact with a serial device that is connected to your computer using a serial port. This is because the serial device may not have a graphical user interface (GUI) or may not be able to communicate with your computer using a network protocol.

Q: What is the difference between a serial terminal emulator and a serial console?

A: A serial terminal emulator is a software program that allows you to interact with a serial device using a terminal interface. A serial console, on the other hand, is a physical or virtual serial port that is connected to a device, such as a router or a switch, and allows you to interact with the device using a terminal interface.

Q: How do I choose the right serial terminal emulator for my needs?

A: To choose the right serial terminal emulator for your needs, you should consider the following factors:

Compatibility: Make sure that the serial terminal emulator is compatible with your operating system and the serial device you are using.
Features: Consider the features that are important to you, such as support for multiple serial ports, support for different baud rates, and support for different terminal settings.
Ease of use: Consider how easy the serial terminal emulator is to use and whether it has a user-friendly interface.
Cost: Consider the cost of the serial terminal emulator and whether it is within your budget.

Q: What are some common issues that I may encounter when using a serial terminal emulator?

A: Some common issues that you may encounter when using a serial terminal emulator include:

Incorrect baud rate: Make sure that the baud rate is set correctly for the serial device.
Incorrect terminal settings: Make sure that the terminal settings are set correctly for the serial device.
Serial port not recognized: Make sure that the serial port is recognized by the operating system.
Serial device not responding: Make sure that the serial device is responding to the serial terminal emulator.

Q: How do I troubleshoot issues with a serial terminal emulator?

A: To troubleshoot issues with a serial terminal emulator, you should follow these steps:

Check the serial port: Make sure that the serial port is recognized by the operating system.
Check the baud rate: Make sure that the baud rate is set correctly for the serial device.
Check the terminal settings: Make sure that the terminal settings are set correctly for the serial device.
Check the serial device: Make sure that the serial device is responding to the serial terminal emulator.

Q: What are some popular serial terminal emulators for Linux?

A: Some popular serial terminal emulators for Linux include:

Minicom: A terminal program that allows you to communicate with a serial device.
Screen: A terminal multiplexer that allows you to communicate with multiple serial devices.
PuTTY: A terminal emulator that allows you to communicate with a serial device over a network connection.
Serial: A terminal program that allows you to communicate with a serial device.

Q: How do I configure a serial terminal emulator to ignore RTS and DTR signals?

A: To configure a serial terminal emulator to ignore RTS and DTR signals, you should follow these steps:

Use Minicom: Minicom allows you to ignore RTS and DTR signals by setting the "Hardware flow control" option to "No".
Use Screen: Screen allows you to ignore RTS and DTR signals by setting the "Serial" option to "No".
Use PuTTY: PuTTY allows you to ignore RTS and DTR signals by setting the "Serial" option to "No" and the "Hardware flow control" option to "No".

Conclusion

In conclusion, serial terminal emulators are an essential tool for interacting with serial devices in Linux. By understanding how to use a serial terminal emulator and troubleshooting common issues, you can successfully interact with serial devices and complete your tasks.