Exploring the Applications of Microcom (with examples)

Microcom is a lightweight terminal program that enables users to connect to remote devices through serial, CAN, or telnet connections directly from the console. Its minimalistic design caters to users who need direct, bare-bones communication with these devices, making it a valuable tool in areas such as embedded systems, network configuration, and hardware debugging.

Use case 1: Open a Serial Port Using the Specified Baud Rate

Code:

microcom --port path/to/serial_port --speed baud_rate

Motivation:

Communicating with remote devices via serial ports is a common requirement in fields like embedded systems and hardware development. These devices often require specific settings to ensure proper communication. Microcom allows developers to establish a direct connection to a device using a particular serial port and baud rate, which is crucial for diagnostics, configuration changes, or simple data transfers. The simplicity and efficiency of Microcom make it a preferred choice for users who need to manage these connections via the command line.

Explanation:

• --port path/to/serial_port: This argument specifies the serial port you intend to open. Typically, this would be something like /dev/ttyS0, /dev/ttyUSB0, or other serial devices connected to the system. The path indicates the exact device file representing the serial port.

• --speed baud_rate: Here, the baud_rate is specified, which controls the speed of data transmission over the serial connection. Common baud rates include 9600, 19200, 38400, 57600, and 115200, among others. Choosing the correct baud rate is essential for ensuring data is transmitted and received correctly between devices.

Example Output:

Welcome to microcom - Type ^\ to quit.
Connected to /dev/ttyS0 at 115200 baud rate.
Device: Hello, I am your device responding via serial!

In this example, a successful connection to the device over a serial port at the specified baud rate is established. The output from the device confirms that communication is occurring as expected.

Use case 2: Establish a Telnet Connection to the Specified Host

Code:

microcom --telnet hostname:port

Motivation:

Telnet connections are often used for accessing network devices like routers, switches, or other remote systems where configuration changes or administrative tasks need to be performed. Although telnet is less secure than its modern counterparts (such as SSH), it’s still in use for specific legacy systems or devices that do not support newer protocols. Microcom provides a quick and efficient means to connect to a host using telnet, which can be invaluable for network administrators or IT specialists managing older equipment.

Explanation:

• --telnet hostname:port: This argument specifies the host you wish to connect to via telnet, including the required port number. The hostname can be an IP address or a domain name, and the port specifies the network port to connect to on that host, with the default for telnet usually being 23. This setup allows users to remotely configure and manage the host from the command line.

Example Output:

Welcome to microcom - Type ^\ to quit.
Trying 192.168.1.1...
Connected to 192.168.1.1.
Escape character is '^]'.
Device: Welcome to Device Manager CLI!

The example output demonstrates a successful telnet connection to the device at the specified hostname on the given port. The greeting from the device confirms the establishment of the connection, allowing the user to proceed with necessary operations.

Conclusion:

Microcom stands out as an effective terminal program for users needing to access remote devices using serial, CAN, or telnet connections. By covering use cases such as opening a serial port with a specific baud rate and establishing a telnet connection to a designated host, Microcom proves its utility across various technical and professional domains. Whether managing hardware devices or handling remote network tools, Microcom provides simplicity and reliability in connecting and communicating with distant systems.