Configure Minicom For Serial
Roseanne Devon
minicom is a serial communication program that connects to devices through a GNU/Linux PC's serial ports. If run by calling its name without any additional arguments, it uses whatever settings have been saved for its defaults in /etc/minicom/minirc.dfl. For those using Windows, PuTTY is a viable application to make such connections between a Windows PC and one of our EMAC devices. More information about PuTTY can be found at
Please note that while PuTTY will work, it is missing a number of features relative to a real Linux terminal. In particular, a number of keystroke shortcuts will not work with PuTTY, and not all output will be displayed correctly in PuTTY (although it does manage to display most output correctly). For serious work with Linux, a real Linux terminal (such as minicom, described here) is strongly recommended.
The use of a terminal emulator, such as minicom, is required when connecting to an EMAC board via a serial console. This page sets out to provide general information about using minicom to communicate between EMAC machines and a development PC.
Another method to set minicom to always display in color is to set an alias for minicom to minicom -con. However, doing this could lead to problems or confusion when trying to run minicom with other aliases or with a very specific set of commandline options, so the environment variable method should be used instead wherever possible.
You will most likely wish to modify the Serial Device setting to have the path to the serial port you normally use. This way, you'll be able to run the command without any options or commands. Press the 'Esc' key to be be brought back to the configurations page.
The next setting that needs to be configured is the Modem and dialing. Press the 'A' key and delete its content. Hit the 'Enter' key to set the setting as blank. Also do this for B through H and K. Hit the 'Esc' key when finished deleting the content of these settings.
Log in, if necessary, with the appropriate username and password for the device. Login information can be found here.You're now able to communicate to the device and use minicom in the same way as using the terminal for the device.
This program is a very important tool for developers. The serial console is essential for working with the bootloader on ARM systems, since U-Boot cannot be accessed via ssh. Using the serial console, you will be able to configure the bootloader, to program new kernels via the bootloader, to program new filesystems, to make a copy of the filesystem on a board, and to perform memory checks using U-Boot. The serial console will also enable you to see startup and shutdown messages, to configure and debug the system when networking is not configured or is not working, and to debug the system when the machine is not booting up.
I recently wrote about my first experience connecting to the pinephone via serial console. This post documents how to configure Minicom for establishing an interactive terminal session with a device connected to your computer via a serial port. The configuration will be saved to file so that it can be reused to connect to the same device again in the future, which is convenient. My version of minicom at the time of writing is minicom version 2.7 (compiled Jan 8 2018).
In my case the TTY device name was ttyUSB0; however, if your cable is not a USB converter, then it might be named ttyS0 instead. If your system architecture is ARM, you might see a name like this ttyAMA0 and if it is a Samsung, then the device might be named ttySAC0. There are more serial port names than I mention here. Also, the index number at the end of the name is determined by the devices minor number and may not be 0. The device name for a serial connection is properly referred to as a serial port. The rest of this blog post will simply use ttyUSB0 as the name of the serial port, but you must use the correctly named serial port assigned to your connected device if you are following along.
Our user account requires rw permissions to initiate a connection with the device. This is achieved by adding the correct group membership to our user account. We can look up the required group membership using the ls command.
The output from ls shows us that the uucp group has rw permissions to the device. Another common group that is used for the group ownership of serial devices is the dialout group. If your system uses the dialout group rather than uucp, then in your mind simply substitute dialout in place of uucp for the rest of this post. It makes semantic sense for the dialout group to be used if the device is a modem or a fax.
Hit to return to the configuration menu. Use the down arrows to select Modem and dialing and hit to navigate to the Modem and dialing parameter setup screen. Blank out fields A through I and K by pressing each key binding and using the backspace button to clear the field. Press the key to commit each field edit. The menu should now look like this:
Hit to return to the configuration menu. Use the down arrow to select Save setup as ttyUSB0.pinephone and hit . Finally, arrow down until Exit is highlighted and press . You should now be back at the Welcome screen. Type A x to quit.
The names of each setting in your custom configuration file should match mine with the exception of the port name. If you edited any other lines, even if you did not change the value, the edited setting will also be written to the configuration file. For example, if you edited the line speed, then you will also see settings for baudrate, bits, parity and stopbits.
You will see a lot of output being written to the screen as your device loads. In the end, you should see a login prompt. Since minicom is a terminal emulator, you can click on the screen and enter your login credentials as if you were connected to the device with a keyboard and monitor.
That is because /dev/ttyUSB0 is being initialized in cooked mode and therefore some translation is being done by the line discipline before it is received by the TTY and ultimately minicom. In order to run ncurses applications correctly we need the TTY to be initialized in raw mode. That can be achieved using the stty raw -F /dev/ttyUSB0. However, when raw mode is configured in this way, minicom still appears to perform its own bytestream translation. I also tried setting the -l optional flag to enable literal translation, which translates IBM line characters to ASCII. Perhaps there is something that I have missied here. Please feel free to comment if you have suggestions.
Looking for some assistance testing a UART implementation with hardware flow contorl for the OMAP L138. To test the implementation I use minicom to emulate the other end of the serial link and I'm looking for some insight into how it needs to be configured.
I have a simple application that sends messages over UART from the OMAP to minicom. This works as expected if both OMAP and minicom are configured to NOT use hardware flow control. When I turn hardware flow control on, I don't see any output on minicom.
However, the changes to minicom listed above don't seem to be sufficient to get flow control to work correctly. After starting the application, the RTS(request to send) signal from the OMAP goes low, indicating to minicom that it wants to send data. If configured properly minicom should pull the OMAP's CTS(clear to send) signal low and start accepting data until it reaches the specified receive buffer threshold. This does not happen. The CTS input to the OMAP is always high. Just for kicks, I tried shorting the RTS to CTS on the OMAP and voila, the expected messages do show up on minicom! Here's an image that shows how the two are hooked up.
The specific Cisco switch I configured was a Catalyst 3560 series PoE-48. I am sure these direction will work with other similar devices. Since I am an openSUSE user, the directions are tailored as such.
My first step was to find a piece of software that would work for me for this and I am sure that there are a ton of solutions but the one that worked the easiest for me was minicom. I am open to other suggestions, of course.
Before you can set up Minicom, you will have to determine where the serial port is that is connected to your computer. In my case, I have ttyS0 but if you have a USB serial port device, you may have something like ttyUSB0 or similar.
Now that you have an idea as to the name of your serial port you can begin the setup process. Some adjustments are needed so that you can successfully communicate with the router. In the terminal type:
Over the weekend, I was showing Linux and Packet radio and for some reason I could not talk to my TNC, a KPC 3+. It was at this point that I realized I had forgotten more about Linux (and minicom) than I had about the commands needed to control the TNC. So, in the interest of helping save you some time, here is a quick write up on using minicom with a USB/Serial adapter to talk to your TNC, specifically, a KPC.
Minicom is an old school program that is available for most of the distributions but may not be installed by default. The good news: it is in all the repositories, so you can pull it down and install it quickly.
Select "Serial port set up" from the list with the cursor keys and set
the serial device and the Bps/par/bits (8/N/1 and whatever the speed
of your TNC is). Press , Save setup as dfl to save your
settings and then select Exit to enter minicom.
One thing to note. Minicom has a much smaller set of connection speeds. For overall interoperability, it is best to set the baud rate of your TNC to 9600, with 8-n-1 for parity. This will facilitate connectivity with a multitude of devices, including a simple VT220.
Those who work with infrastructure/server deployment knows how difficult it is to get a console for those devices having no display like switches, routers and a blade chassis/enclosure. Usually we use any console connection utilities like putty, minicom, RealTerm or cu. Here I am explaining how to configure minicom in linux for a console connection to Cisco Nexus 5K switch.
7fc3f7cf58