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3Aug/123

Using minicom to interface with serial devices on Linux

I came across a problem recently, I needed to configure a Cisco switch and all I had was a Ubuntu machine that had a serial port. Since then I've got a Cisco 2511, with octal cable, which is very handy when configuring many devices, but that is for another post.

I found a program called 'minicom' which is available as far as I'm aware in all the main repositories. This post is a brief explanation on how to find your serial port and setup / use minicom.

1. First of all lets start with finding the computers serial ports, make sure you have your device powered on and connected:

dmesg | grep tty

Listing Linux serial devices

This shows in my example that the physical serial port is at ttyS0, where as usb > serial converters will show as ttyUSB0

2. Time to open up minicom, I believe the later versions will allow running as an unprivileged user, but this will mean that you can not save configurations. Better to run as root if you have the option.

Start-up Minicom

Default page after starting Minicom

3. Checking the options available is very easy, to put minicom in to command mode control+a needs to be pressed, with a following 'z' to show the options. For example, control+a then x will close minicom.

Minicom Options

4. Now it is time to setup minicom, as you can see from the help page you need to use control+a then o (for options). Scroll down to "Serial port setup" and hit enter.

Minicom serial settings.

5. From there is is pretty straight forward to follow the prompts to change to your required settings. Typically Cisco networking equipment uses 9600 Bps/Par/Bits, "8-N-1", Yes to Hardware Control Flow and no to Software Control Flow. Also set your serial device to the one you found in the first step.

Minicom Cisco Settings

6. Now save your configuration for quicker access in the future, personally I save it as "Cisco".

Saving configuration

7. Now close minicom with control+a then x will prompt you the option to close the program or simply scroll to "Exit".

Resetting Minicom

8. If you saved a configuration within minicom, it can be used to open minicom directly in to those settings. For example, "minicom cisco".

Initialising Minicom

9. Everything should be ready for using your serial device.

Functioning Minicom

4 responses to “Using minicom to interface with serial devices on Linux”

  1. stanley says:

    hey

    thanks alot. I want to use this to read pulses from an arduino and save it in a database.

    I have opened the minicom properly but I dont know where to type the code to read the data from the arduino. When I try to type something all I get is some characters not words.

    please. ur help will be very appreciated.

    Regards.

    • admin says:

      I would suggest checking if you have the right baud rate.

      • Stephen says:

        Stanely and or admin,

        Did you get the arduino setup working properly? I’m trying to do the same thing with similar boards that have relays and analogue inputs. I want to check the inputs once per second and save the results in a text file.

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