Questions tagged [serial-port]

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 or RS-422.

Filter by
Sorted by
Tagged with
0 votes
0 answers
6 views

Get tty device paths for zte MF710M modem

i am trying to get the device paths for my modem zte MF710M using this script #get all connected devices usb-devices T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 21 Spd=480 MxCh= 0 D: Ver= 2.00 Cls=...
user avatar
  • 3
0 votes
1 answer
33 views

Dumb terminal agetty keyboard layout filter

I recently acquired an old Heathkit dumb terminal, and I would like to get it working with the colemak keyboard layout. Because the terminal sends ascii codes directly over serial, I don't believe ...
user avatar
  • 31
0 votes
1 answer
36 views

Serial port to COM port - no output found

I am using Ubuntu WSL1 in Windows. I want to find my serial port which is currently connected on COM4 and I am running this command: dmesg | grep tty, dmesg | egrep tty, setserial commands, but ...
user avatar
0 votes
0 answers
14 views

How to make PPP retry when it fails with "LCP: timeout sending Config-Requests"?

I have a (working) PPP link between two Linux boxes. The configs are: $ cat /etc/ppp/peers/nullmodemserver ttyUSB0 38400 nocrtscts local 10.11.12.13:10.11.12.14 #0.0.0.0:0.0.0.0 passive persist ipcp-...
user avatar
  • 581
0 votes
0 answers
174 views

CP210x / CC2652RB (slae.sh zigbee) serial missing on ubuntu 22.04

I'm using Ubuntu 22.04. I just bought CC2652RB USB Zigbee (https://slae.sh/projects/cc2652/) but in my Ubuntu it doesn't create the /dev/serial folder. This is the sudo lsusb -d 10c4:ea60 -v output ...
user avatar
  • 121
1 vote
1 answer
29 views

PPS on focal/20.04 timed out and never recovers

we recently have upgraded to a new industry PC from Vecow/Plugin and to Ubuntu 20.04 from 18.04. From the BIOS (build date BIOS ~17.02.2022) and the IO chip according to it is a SuperIO 8786: https://...
user avatar
4 votes
1 answer
114 views

Is there a difference in serial data formatting between Linux and Windows?

I am trying to read in serial data from an RS-485 RFID reader using a RS-485 to USB converter found here and a python script running Pyserial. The issue I'm facing is that when I print out what is ...
user avatar
0 votes
0 answers
87 views

Is /dev/ttyUSB0 a TTY?

I know the title of the question sounds a bit silly, but that's the best I could think of :) As far as I understand, if I have some serial device connected with USB - let's say I connect my Arduino to ...
user avatar
  • 264
1 vote
0 answers
132 views

Split serial port into two virtual ports

This question is related to this post here: Cloning/Splitting a serial port (COM) port in Ubuntu I followed the steps to make the virtual ports but the problem is that I need full-duplex ...
user avatar
  • 111
0 votes
1 answer
83 views

No login prompt from Getty over serial console

My Ubuntu 20.04 system has a serial port over which I would like to provide console access. I can confirm that I can communicate over the serial port with sudo picocom -b 115200 /dev/ttyS5 I start ...
user avatar
  • 121
0 votes
0 answers
28 views

How to add cp437 support into Minicom?

I am using a Raspberry Pi (running Raspbian) to act as translator between SSH-over-Ethernet and an RS232 connection to a proprietary hardware box. This proprietary box seems to be using CP437 ...
user avatar
  • 101
0 votes
0 answers
20 views

How to make a static SPI driver module dependent

I have a custom SPI ethernet driver which I want to load only after the SPI main driver has loaded. If I add both drivers as static my ethernet driver is failing because the driver is loaded and is ...
user avatar
  • 1
0 votes
1 answer
51 views

redirect TTY input to output without serial cable

I'm using simulation software for unix (ucsim) that runs two simulated programs that supposed to connect to each other via its own simulated serial ports. The software provides me with these methods ...
user avatar
  • 1
0 votes
0 answers
96 views

How to write bytes to serial port's input buffer

I'm working on creating an emulator for a Captron button that is connected to a serial port /dev/ttyS0. I'm trying to mimic the on-press action by writing a byte array to the serial port by printf /...
user avatar
0 votes
1 answer
99 views

How to find the relation between a USB/TTL (dev/ttyUSB_) and it's GPIO pins (/dev/gpiochip_)

I have a number of USB/TTL adapters, based on CP2102N, which have four GPIO lines. I can open one of the serial devices by /dev/ttyUSB0, and the related GPIO lines are controlled by libgpiod: /dev/...
user avatar
1 vote
0 answers
23 views

Application locked in the read() of a serial port device

OS Linaro on arm machine. I'm writing a C console application that communicates with a USB device that exposes a virtual serial port profile. Sometimes happens that the USB device is disconnected (and ...
user avatar
  • 115
0 votes
0 answers
29 views

Serial UART Mode reverts to RS232 on boot

I'm using a Moxa Linux unit, Debian 9, and the port0 mode needs to be set to mode 1, 2 wire RS485. I use a startup script instigated via crontab which does work as the associated app restarts, but the ...
user avatar
0 votes
2 answers
127 views

Is there a way to ssh tunnel, and access a device in the /dev directory, and use it as if it is local? [duplicate]

Is there a way that one computer can share the a device in the /dev/ directory with another computer, and the other computer can interact with it is if it is local? Something analogous to an SSH ...
user avatar
1 vote
0 answers
79 views

Troubleshooting RS485 comm on Beaglebone black with cape comms2

TLDR: my serial comm (RS485) does not work on the BeagleBone Black. How to fix that? —— Following my previous question which didn't find any solution, I am now exploring the linux side of the ...
user avatar
0 votes
1 answer
61 views

Trouble finding on-board serial port via UART: "-bash: echo: write error: Input/output error"

I have an old tv box that I wiped recently with Linux. I would like to connect a device to its onboard UART pins, to which I've soldered wires that connect to a UART adapter on my PC. I opened up a ...
user avatar
  • 1
0 votes
0 answers
22 views

Debian USB CDC devices not passing DCD?

I have a home-made USB connected GPS receiver. It's a GPS module connected to a CY7C65213 CDC UART. The serial I/O works just fine. The PPS output from the GPS module is inverted and connected to !DCD....
user avatar
  • 111
1 vote
0 answers
30 views

Using BRKINT With Pseudo-Terminals

$ screen $ stty -ignbrk brkint $ sleep 10 If I now press Ctrl-A+b to trigger a serial break, why is no SIGINT sent to the foreground process group sleep 10? Are serial breaks not implemented for ...
user avatar
  • 145
0 votes
1 answer
148 views

How to query USB serial device, capture output and exit?

I have several Arduino devices, connected to linux box. The only difference between them is what they answer on connect. They are not distinguisheable by lsusb command. Although I don't know how to ...
user avatar
  • 2,617
0 votes
1 answer
131 views

Where can I install systemd service that executes zsh script as early as possible

I am wondering where can I install this service that executes zsh script to run my script as soon as possible. Script uses serial port at /dev/ttyS5 and gpio pins. Is there a earlier target than multi-...
user avatar
0 votes
0 answers
32 views

Out of sequence data in sensor monitoring program

I am logging data on a long term basis from four USB serial ports on a Raspberry Pi that ultimately needs to get to another machine on the local network for further processing. There are a couple of ...
user avatar
0 votes
0 answers
12 views

Is it possible to have an application register for SLIP frames?

I am integrating a device on an embedded system that happens to use SLIP framing over RS485. Is there a technique that will allow my application to block until the arrival of a SLIP frame and when I ...
user avatar
0 votes
1 answer
9 views

ISDN: how to set two channels with serial TA?

Playing with retro-computing I have successfully configured a isdn pci TA, to set up the connection I use a script like this #!/bin/sh isdnctrl addif ippp0 isdnctrl addslave ippp0 ippp1 isdnctrl eaz ...
user avatar
  • 11k
3 votes
1 answer
124 views

serial transmission baud rate mismatch

I have two serial ports, one provided via motherboard (/dev/ttyS0) and one from PCIE to RS232 card (Startech 2S952) with Oxford chip (/dev/ttyS1) (there is /dev/ttyS2 but it does not enter this story)...
user avatar
  • 133
0 votes
1 answer
53 views

FreeBSD serial port lock files

Does anyone know when in FreeBSD's boot process /dev/ttyu*.init and /dev/ttyu*.lock files are created? In other words, are they created by the OS within its boot process, or are they created when I ...
user avatar
  • 1
1 vote
0 answers
86 views

How can I run a script via bluetooth and issue commands?

I am fairly new to Linux and I am trying to use beaglebone black (debian) to try and run a script via bluetooth that will allow me to issue some simple commands and have the board do stuff. I am able ...
user avatar
0 votes
1 answer
192 views

Fixed tty device assignments for SPI-UART adapters in Linux/Raspberry Pi OS

I need to use the serial ports that i get from a SC16IS752 adapter. I already set them up from /boot/config.txt, and they appear in /dev as ttySC0, ttySC1, ttySC2 and ttySC3 and they work. The problem ...
user avatar
0 votes
0 answers
48 views

serial8250: too much work for irq36

I am currently working on Poky on an embedded PPC system. I am experiencing a "serial8250: too much work for irq36" problem around 50-75% times I try to boot. What I was thinking to do is ...
user avatar
  • 351
0 votes
0 answers
81 views

Serial port baud rate change - getting "unable to perform all requested operation"

I´m working under CentOS 7 distribution, I have worked with USB to serial converters and everithing works properly, but in this case I´m using a Versalogic MPEe-U2 board attached to a mini PCIe ...
user avatar
0 votes
0 answers
62 views

How to place timestamps on data received via serial port?

Is there a way to get the timestamp at a driver level of when each byte comes from serial port? I want to connect an embedded device but I need to know an approximate time the data arrives, preferably ...
user avatar
0 votes
0 answers
219 views

How to make Modbus RTU RS485 on cape comms2 works on the Beaglebone black?

I am scratching my head for days now, trying to make Modbus RTU RS 485 working on my Beaglebone black having the cape comms2 set and running Debian. I connect to /dev/ttyS0 at 9600 bauds, 8-bit data, ...
user avatar
1 vote
0 answers
73 views

How to get USSD balance from USB Huawei Router

I have a Huawei mobile WiFi E5576-855 connected to my notebook with USB. I can't find the serial port for the device. There is no /dev/ttyUSBx at all, I only see /dev/ttyx. So I can't use gsm-ussd or ...
user avatar
  • 325
0 votes
0 answers
89 views

Get screen serial port in remote

I have some industrial equipment with serial ports equipped. There are 2 serial ports on each one (COM1 /dev/ttySC0 and COM2 /dev/ttyAMA0). Before sending to production, to test the correct ...
user avatar
  • 550
0 votes
0 answers
44 views

Maximum serial port speed in Linux

I installed a brand new xr17v358 serial card, which claims 25Mbps maximum. (For some reason this was the only card I could find that didn't top out at 1950s speeds. I'll settle for 1970s speeds in ...
user avatar
0 votes
0 answers
213 views

BeagleBone Black UART 1 config

Recently I compiled my own linux system using kernel 5.10.23, and I made modifications to the device tree in order to activate UART 1 PIN (9-24) and (9-26). I have /dev/ttyS1 available for R/W ...
user avatar
0 votes
0 answers
46 views

I cannot read from serial port until I login

I have a python script that reads from serial: import serial s = serial.Serial("/dev/ttymxc0", 115200) for i in range(100): with open("test", 'w') as f: f.write(s....
user avatar
  • 117
0 votes
1 answer
350 views

"device disconnected or multiple access on port" error

I'm programming in Python 3 on a Raspberry PI 4 running current Debian. My program uses serial port /dev/ttyS0 to send binary requests to a MP3 player board. The documentation about the MP3 player ...
user avatar
  • 1
0 votes
1 answer
132 views

Serial connection possibility between Windows and CentOs7

I want to establish connection via putty (serial connection) using UC232a adapter connected to null modem cable, connected to mini-serial-to-DB9 adapter and then to another PC with CentOS 7. First of ...
user avatar
2 votes
1 answer
97 views

How do I send values from both pins of the serial port?

I am trying to intercommunicate my linux system with my microcontroller. I have configured DB-9 pins as full duplex RS485 as below: I have connected Pin-7 with Pin-8. I have connected Pin-2 with Pin-...
user avatar
  • 23
1 vote
0 answers
338 views

What are the side effects of using socat to monitor the traffic of a serial port regarding the monitored serial port?

Disclaimer: Long and detailed problem description + I actually have no idea about socat, but ran into a very strange problem. Something similar to a tl;dr at the end. I am currently trying to connect ...
user avatar
  • 11
0 votes
0 answers
64 views

Arduino port keeps changing

I am using a linux mint machine. I have an Arduino which sometimes gets connected to machine on /dev/ttyUSB0, /dev/ttyUSB1 or /dev/ttyUSB2 which fails my script. The problem is I have multiple ...
user avatar
  • 41
1 vote
1 answer
455 views

Ubuntu suddenly "forgets" serial device

So I have this issue with an USB to serial converter. On a fresh booted device it shows up as /dev/ttyUSB0 and I can connect to the serial device with minicom -D /dev/ttyUSB0. However, after some time ...
user avatar
  • 113
1 vote
0 answers
802 views

What is Virtual Serial Port in QEMU?

Ubuntu 20.04 both on host and guest. I'm new to QEMU and trying to set up guest-host communication via serial port. The QEMU documentation says that -serial dev option: Redirect the virtual serial ...
user avatar
  • 211
0 votes
1 answer
249 views

Serial on host stops working during boot

I'm running Proxmox 6.4 with kernel 5.4.103-1-pve (I've already asked this question in their forums with no luck). My motherboard has a COM header, so I recently got the equipment I needed to hook it ...
user avatar
0 votes
1 answer
34 views

wrong serial port speed (multiplied by 8) - CentOS 7

I´m trying to set the baud rate of my serial port using stty -F /dev/ttyS0 9600 the problem is that i check on the oscilloscope I get a 8 times faster baud rate so I need to configure 1200 to get 9600 ...
user avatar
0 votes
1 answer
90 views

What data is actually being sent when you write to a serial port?

If I want to send data to a device serially from my PC, there are 3 things that must be done: I must connect a USB to serial converter (FTDI breakout or similar) to the USB port of the PC The target ...
user avatar
  • 111

1
2 3 4 5
10