A hardware interface commonly found on older PCs, usually with a 9-pin DE-9 socket/plug, on networking devices or servers also with RJ-45 socket/plug (otherwise commonly used for ethernet), or with a (much wider) 25-pin DB-25 socket/plug. Two common standards used with such an interface are RS-232 ...

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33
votes
9answers
143k views

How to connect to a serial port as simple as using SSH?

Is there a way to connect to a serial terminal just as you would do with SSH? There must be a simpler way than tools such as Minicom, like this $ serial /dev/ttyS0 I know I can cat the output ...
28
votes
3answers
7k views

Why do some Linux distributions still have /dev/ttyS0, ttyS1, etc., even though newer computers don't have such a serial port?

Many new laptop and desktop computers do not have 9-pin/25-pin serial ports. Why do many Linux distributions still contain /dev/ttyS0, dev/ttyS1 device files? Since udev can create the device files ...
25
votes
1answer
82k views

reading from serial from linux command line

I have a serial port device that I would like to test using linux command line. I am able to use stty and echo for sending commands to serial port, but when device responds I have no way of reading ...
18
votes
6answers
56k views

How can I monitor serial port traffic?

Is there any port monitoring tool to watch the packets written on the port? I especially want to check if my program written in Java works so I need some kind of tool to see if my little application ...
14
votes
3answers
20k views

How to bind USB device under a static name?

I have an arduino which sometimes gets bound to /dev/ttyUSB0 and other times to /dev/ttyUSB1 making my script fail. I do not want to enumerate all the possibilities of where my device could be, but I ...
14
votes
3answers
24k views

Read/Write to a Serial Port Without Root?

I'm writing an application to read/write to/from a serial port in Fedora14, and it works great when I run it as root. But when I run it as a normal user I'm unable to obtain the privileges required to ...
13
votes
2answers
21k views

How does cat know the baud rate of the serial port?

I regularly use cat to view debugging information in the console from my FPGA development board over the serial connection, but I never have had to tell linux what the baud rate is. How does cat know ...
13
votes
4answers
12k views

Telnet send Ctrl-C

I use telnet to connect to a terminal server, which proxies the traffic to a RS-232 port. Unfortunately when using some of the devices it is not possible to send the CTRL+C character (0x03). Instead ...
11
votes
2answers
14k views

set baud speed for tty

How do I set the baud speed for a specific tty (in this case a serial port)? I tried using stty -F /dev/tty.iap ispeed 19200 But get the error Invalid argument for every speed I try (2400, 4800, ...
10
votes
2answers
10k views

Unexpected results testing serial loopback using echo and cat

So I have a standard RS232 serial port that is looped back to itself by simply running a wire from Tx to Rx. I'm testing loopback by running echo and cat in two separate terminals: cat /dev/ttyS1 ...
10
votes
2answers
7k views

Attaching USB-Serial device with custom PID to ttyUSB0 on embedded

I'm attempting to get an FTDI USB-Serial device with a custom PID to automatically (or even manually) attach to ttyUSB%n, without much success. The device's normal VID/PID is 0403/6001. When ...
10
votes
1answer
13k views

How to find which serial port is in use?

The Question: I plugged in a device (i.e. GSM modem) through a serial port (a.k.a. RS-232), and I need to see with which file in /dev/ filesystem this device was tied up, to be able to communicate ...
9
votes
3answers
7k views

Why does awk do full buffering when reading from a pipe

I'm reading from a serial port connected to a gps device sending nmea strings. A simplified invocation to illustrate my point: $ awk '{ print $0 }' /dev/ttyPSC9 GPGGA,073651.000,6310.1043,N,...
9
votes
2answers
51k views

How to send data to a serial port and see any answer?

On Linux, I want to send a command string (i.e. some data) to a serial port (containing control characters), and listen to the response (which also usually might contain control characters). How can ...
9
votes
3answers
14k views

Send file by xmodem or kermit protocol with GNU screen

I work with an RS-232 device via GNU screen. $ screen /dev/ttyUSB0 115200 At some point I need to send a local file to the device using either the xmodem or kermit protocol. On Windows I use ...
8
votes
2answers
56k views

command to determine ports of a device (like /dev/ttyUSB0)

I have a question regarding the ports in Linux. If I connect my device via USB and want to check its port I cant do it using the command lsusb, which only specifies bus number and device number on ...
8
votes
2answers
3k views

udev rule for assigning known symlinks for identical usb serial devices

I have two (and possibly in the future, more) USB serial devices which are identical (down to the serial number, unfortunately) - they're actually BTC miners. Currently they end up as ttyUSBX where X ...
7
votes
2answers
6k views

How do I know if a serial port is actually transmitting data, without opening the device?

I have a high-availability cluster (Heartbeat) connected via serial line and two ethernet NICs. I'd like to set up a monitoring script capable of recognizing disconnected serial line (basically the ...
6
votes
2answers
877 views

My process was killed but I cannot understand the kernel notice

I have a custom application running on an embedded x86 setup (built using buildroot and uClibc). The application has been running fine but this morning when I returned to work I discovered my process ...
5
votes
2answers
4k views

How can I listen to communication between a process and a serial port?

On a Gentoo Linux machine, a process is communicating with another computer via serial port (/dev/ttyS1). I want to listen to this communication (i.e. what is being sent/received by the process) ...
5
votes
2answers
4k views

How to send data from serial port over wifi?

I have microcontroller device which reads data from sensors and sends it via Serial to USB converter (ftdi232 cable). This Serial to USB converter is connected to ARMv7 mini-computer - CuBox with ...
5
votes
1answer
9k views

serial data over ethernet on a linux box

I'm trying to connect a widget (192.168.1.214:20108) through Ethernet (serial to Ethernet) to a Linux box. Under Windows using a virtual device driver mapping I can see the serial data, so I know ...
5
votes
2answers
877 views

RS232 chat. Simplest way?

I'm working in a project in which I will have to deal with serial communications. For testing, I want make to 2 computers speak to each other (with my interaction) via RS232. Will the next thing work?...
5
votes
1answer
2k views

Reading from serial port in the simplest way?

I have a TrueRNG USB-based hardware RNG, and I am trying to read its output on Mac OS X 10.9.2. I need just one-way communication. The device says that it appears as a "CDC Virtual Serial Port", and ...
4
votes
3answers
5k views

cat corrupts serial port data

I have an application which writes some bytes to a serial port. When I do cat /dev/ttyS0 to see what is being transferred, I find that the data is corrupted by the cat command. Is there any other way ...
4
votes
3answers
31k views

How to send AT commands to a modem in Linux?

In Linux (Ubuntu) I am trying to send AT commands to a modem at /dev/ttyACM0. I tried to do it as: sudo socat - /dev/ttyACM0 but when typing anything I just get a line repeating this command (I ...
4
votes
2answers
958 views

What is the TTY major number of your Unix?

I'm currently working on a serial port library which already uses special frameworks to get information about serial ports on the system. Though serial ports are a fundamental design in Unix—as ...
4
votes
4answers
25k views

PuTTY can access serial port as /dev/ttyUSB0, but not as named udev device

I have multiple USB-to-serial converters. I need to access one of them in particular. I'm using a udev rule to give it a special name. I have rebooted since I last modified it. SUBSYSTEM=="usb", ...
4
votes
1answer
8k views

Reading from USB serial port under Cygwin

I am actually using Cygwin, but it is my understanding that it responds to Unix commands so hopefully I am in the correct place. I have an Arduino hooked up via USB to my LapTop for data reading. I ...
4
votes
1answer
22k views

How do I access a USB serial port without an entry in /dev?

I have a USB to serial adapter based on the SiLabs CP2101 chipset. I'm trying to use it with Debian 5.0 Lenny (armel architecture). I seem to be able to get the proper kernel module to recognize the ...
4
votes
1answer
128 views

Find correct tty & tty settings

I managed to run pure Debian (debootstraped) ON my Android-based device. That means that my Nexus 5 runs a perfectly normal GNU/Linux system but with the CyanogenMod 11 Linux kernel (has some model-...
4
votes
1answer
2k views

How do I test that two connected serial ports really transmit data?

I have a device with two serial ports which I connected together, and I SSH into it. I would like to send data via one of the serial ports and read it from the other, to see that they do transmit/...
4
votes
2answers
2k views

Buffer overrun on Fedora 16 serial

I got a brain smashing problem with Fedora 16 and my serial port. I use the serial to monitor an STB on which I'm developping. The STB runs on Linux and when booted, I launch the program I'm working ...
4
votes
1answer
3k views

Comunicate with remote Serial over TCP/IP as /dev/ttyX device

I've one serial device on 192.168.x.x:yyyy (where "x" and "y" are real number) and it works correctly. But I want to communicate with this as /dev/ttyX device. I've tested socat command but not ...
4
votes
2answers
7k views

Cannot change baud rate on usb serial device

I recently upgraded to ubuntu 12.04 from 10.04. Under 10.04 I had no trouble using usbserial driver to connect to a device through the serial port. After the upgrade usually I cannot reset the baud ...
4
votes
1answer
704 views

Low-level serial configuration?

I'm using embedded Linux platform, kernel is 2.6. I'm using stty command to configure ttyS* high level. The problem is that when I want to turn hardware flow control on: stty -F /dev/ttySA0 crtscts ...
4
votes
1answer
432 views

Viewing (monitoring) line status of a serial port

Is there a utility software (or an easy method to do it from shell script) to display a serial port's status — i. e. blinking “RXD”, “TXD”, “DCD”, “DTR”, “DSR”, “RTS”, “CTS”? Particularly, I need to ...
4
votes
1answer
82 views

UUCP on old Xenix with serial line no modem

A little question about UUCP on Xenix or other old Unix. I have set up UUCP as follow: Devices Direct tty2a - 9600 direct Systems xenix2 Any Direct tty2a 9600 12345 in:--in: user word: password ...
3
votes
1answer
1k views

What is the complementary command to 'rx' for xmodem transfer?

I have an installation of busybox on an embedded linux system that comes with a great little utility called rx: rx FILE Receive a file using the xmodem protocol This is perfect for transferring ...
3
votes
2answers
308 views

How do I convert my old PC to a data logging and presentation terminal?

Take an old PC (e.g. 1.8GHz P4 with 256MB RAM), install e.g. Ubuntu 10.04 LTS on it. Now go to your PIC or AVR based home project and hook up the thing. With only three connections and the onboard ...
3
votes
4answers
2k views

Fetching individual bytes from a binary file into a variable with bash

I need to make a fairly simple bash script to pull bytes one at a time from a binary file, send it out a serial port, and then wait for a byte to come back before I send the next one. This is ...
3
votes
1answer
4k views

How do I use a serial port on Linux like a pipe or netcat?

I have two computers with two serial ports: ttyS0 and ttyUSB0. (Actually they are on the same computer but that's just for testing). The ports are connected via null modem cable. I want to be able to ...
3
votes
5answers
904 views

How do I configure my tty session such that a form feed `\f` character will clear the terminal?

I'm connecting to a USB-serial connection on /dev/ttyACM0. The code on the sender side is sending a \f character at regular intervals. print("----------------------------\n\r"); print("-- LED ...
3
votes
1answer
160 views

Serial File Transfer without lrzsz

I have a device running Raspian, that does not have the lrzsz package installed on it. I only have a serial port to the device, and can connect to the device using screen or minicom, but unfortunately ...
3
votes
2answers
2k views

terminate screen monitoring serial port

I'm using screen /dev/tty-MyDevice to look at traffic on my serial port. Pressing Ctrl+D doesn't cause the screen to terminate. How do I terminate it? Thanks
3
votes
2answers
285 views

Reading from a serial interface

I have a serial device running which I need to read data from(I have absolutely no control over the device itself) except reading its output; using hyper terminal in Windows I am able to detect a ...
3
votes
2answers
85 views

Redirect console to a serial port

I have a serial port /dev/ttyS2 that is connected to a supervisor. Normally, I use this line to send commands back and forth between CPU and supervisor. However, under some settings, I want to just ...
3
votes
4answers
4k views

udev re-numbering when creating symlinks

I have USB cellular modem attached to an ALIX 3d2 board running voyage linux (which is based on Debian Squeeze). The modem registers itself as a TTY device, and so by default, udev will create TTY ...
3
votes
1answer
104 views

termios settings after closing file

Are the settings altered by functions from termios.h kept after file is closed and open again? I want to use serial communication in a higher level language (Racket) which exposes only reading and ...
3
votes
1answer
416 views

Is it possible to have two seperate one way (simplex) serial ports to make single tty device?

I am building embeded device, which has IR comunication with PC and it will have two IR Led/detector pairs which are one-way and are setup like this: IR source input commands -> near embeded device ...