How to use the command 'minicom' (with examples)

Minicom is a powerful command-line utility used to communicate with devices through a serial interface. It is especially useful when interfacing with embedded systems, modems, and other serial devices. Think of Minicom as a terminal emulation program that allows you to send and receive data on a designated serial port, often found in Linux environments. Its intuitive interface makes it an ideal choice for users who need to configure or troubleshoot hardware over a serial connection.

Use case 1: Open a given serial port

Code:

sudo minicom --device /dev/ttyUSB0

Motivation:

When dealing with embedded systems, network equipment, or other devices that provide a serial interface for diagnostics or configuration, direct serial port communication is often necessary. This command is the most straightforward way to initiate a connection with a serial device. It is particularly useful when you need to start a session quickly to monitor or interact with the device to see what data is transmitted in real-time.

Explanation:

• sudo: This command is run with superuser privileges because accessing hardware device files usually requires elevated permissions.
• minicom: This is the main command, launching the Minicom terminal emulator.
• --device /dev/ttyUSB0: Specifies the serial device file to open. /dev/ttyUSB0 is a commonly used path for USB to serial converters on Linux systems. It indicates which port the data communication should occur through.

Example Output:

Welcome to minicom 2.7

OPTIONS: I18n 
Compiled on Feb  7 2016, 13:37:27.
Port /dev/ttyUSB0, 22:40:57
Press CTRL-A Z for help on special keys

Use case 2: Open a given serial port with a given baud rate

Code:

sudo minicom --device /dev/ttyUSB0 --baudrate 115200

Motivation:

Many devices require communication at a specific baud rate, which is the speed of data transmission in bits per second. By default, Minicom attempts to connect at a standard baud rate, but this might not match the baud rate the device is currently set to. Specifying the baud rate ensures that the data sent and received is interpreted correctly. This setup is critical in ensuring proper communication and avoiding data loss or miscommunication with the device.

Explanation:

• sudo: Executes the command with elevated privileges necessary for accessing hardware device files.
• minicom: Launches the Minicom terminal emulation program.
• --device /dev/ttyUSB0: Indicates the serial device to connect to.
• --baudrate 115200: Sets the communication rate to 115200 bits per second. This is a common baud rate for high-speed communication with modern devices, ensuring that data can be sent and received quickly and accurately.

Example Output:

Welcome to minicom 2.7

OPTIONS: I18n 
Compiled on Feb  7 2016, 13:37:27.
Port /dev/ttyUSB0, 22:45:03

Press CTRL-A Z for help on special keys

Use case 3: Enter the configuration menu before communicating with a given serial port

Code:

sudo minicom --device /dev/ttyUSB0 --setup

Motivation:

Entering the configuration menu allows users to adjust various communication parameters before establishing a connection. This feature is advantageous when dealing with devices that might not use default settings or require specific configurations such as flow control, data bits, parity, or stop bits. It provides an opportunity to customize the connection settings to match the device’s specifications, ensuring reliable communication.

Explanation:

• sudo: Needed for superuser access to system hardware devices.
• minicom: Invokes the Minicom program.
• --device /dev/ttyUSB0: Specifies the serial device for connection.
• --setup: Opens Minicom’s configuration interface, allowing users to adjust settings related to the serial communication parameters before connecting.

Example Output:

+-----[configuration]------+
| A - Serial Device : /dev/ttyUSB0         |
| B - Lockfile Location : /var/lock        |
| C - Callin Program :                     |
| D - Callout Program :                    |
| E - Bps/Par/Bits : 115200 8N1            |
| F - Hardware Flow Control : No           |
| G - Software Flow Control : No           |
|                                           |
| Change which setting?                    |
+------------------------------------------+

Conclusion:

Minicom is an essential tool for anyone needing to communicate with devices over a serial interface. Through various examples, users can quickly set up connections, configure communication parameters, and ensure reliable data transmission with those devices. Whether you need to perform diagnostics, debugging, or setting configurations, Minicom provides a versatile solution to address those needs effectively.