Questions tagged [uart]
The uart tag has no usage guidance.
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Why is the serial communication with this device failing?
I have two serial to USB adapters connected to my computer, each one is connected to a microcontroller.
What I want to do is send commands to each microcontroller through UART (I'm using minicom), but ...
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1
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How do I tell a /dev/ttyUSBN device that it's a master?
Using the terminology of ptys, the slave end connects to the CLI program and the master end connects to the user / keyboard / terminal emulator.
I have an FTDI USB UART connecting my laptop's USB port ...
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How to make use of an M2 PCIe card UART interface?
I have a motherboard (AIMB-218) with an M2 E key slot and according to the documentation of the said motherboard the M2 slot supports UART.
I am trying to use a wireless module (Wi-Fi + Bluetooth), ...
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How to integrate radio modules to Linux networking stack
I want to know whether it is possible to add a radio link (point-to-point) to the link layer of the networking stack on Linux so that programs can communicate using TCP/IP.
Assuming the only way to ...
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Minicom: send string when newline is detected
I have 3 different USB-to-UART FTDI cables and use minicom to debug some device.
My problem is only one of these cables can buffer characters until I send a newline. Eg when I type the string "...
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Reading /dev/ttyS4 from a BeagleBone running Debian 10 not what is written
I am pulling my hears trying to make ttyS4 up and running on a Beaglebone black.
I have set up UART4 in my /boot/uEnv.txt (see it at the bottom of my question).
On the Beaglebone I have the comms cape ...
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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 ...
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Manually installing drivers on Linux Mint
I am currently trying to install a driver through terminal. It is for the USB UART XR21B1411 serial port adapter. I installed it in the past, but cannot remember how I did it. Here is a link to the ...
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1
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444
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Enabling second UART in U-Boot
I am working on a project with SAMA5D3-xplained board with CortexA5 processor and embedded Linux. I would like to send and receive some data via UART during U-Boot is running and before a kernel is ...
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The linux boot message in dmesg doesn't output to uart
My problem is my linux is success for boot but there is no more boot message output to uart(ttyPS0) after "Starting kernel...".
As you can see in the pic, there is a lot of boot message in ...
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How to redirect GRUB2 output to a MMIO serial UART?
Is it possible to redirect GRUB2 output to a MMIO serial UART?
For example I have a UART that is displayed in a Linux boot log as:
AMDI0020:01: ttyS5 at MMIO 0xfedca000 (irq = 4, base_baud = 3000000) ...
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481
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How are the TTY and serial_core related?
I need to write a new character device file for the UART, which allows a few more file operations than usually allowed (not just open, write, etc..)
I'm on an embedded mainline linux kernel (v 5.4).
I ...
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How does the kernel interacts with drivers and device tree?
I have an embedded linux system running on a board. I had, in the device tree, the uart device, and also a driver for that. In that case, after boot, I could see a /dev/ttymxc0 "file" in the ...
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Use rs485 driver specifying the DE pin
On an embedded system (STM32MP1 w/ Yocto environment) I need to control an rs485 transceiver.
Unfortunately, the DE pin of the transceiver is connected to a generic GPIO pin of the MPU and not to the ...
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How to active the second console to a FreeBSD guest running in bhyve?
Background
I'm running FreeBSD 12.1-RELEASE as a host for bhyve virtual machines.
I have a FreeBSD 12.1-RELEASE guest running inside a VM. I would like to have two TTY-class devices configured for it.
...
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Samsung SMT-G7401 hack
Samsung SMT-G7401 hack
introduction
I have an SMT-G7401_PCS01B (Horizon box) from UPC Switzerland and I would like to install debian or multimedia linux distribution on it if is it possible, if is ...
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Bash script - Watch serial-port for specific string, then send back commands
I try to use a bash script to watch the serial-port for a specific string. If this string is shown, some commands should be send back to the connected device. It´s a router I am connected to. It is a ...
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What does PS in ttyPS* stands for?
What does PS in ttyPS* stands for?
Where, in general, can I find the expanded names of devices under /dev?
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Raspberry Pi UART not working
I've tried everything. Raspberry Pi 4 echo works. Linux echo works. But when I connect the two UARTs together, no information is sent.
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Is there a limit to the number of FTDI connections on Debian 9?
I have a Debian 9 box, and if I plug in 1 of my devices, its UART shows up in both lsusb and in the output of ls /sys/bus/usb-serial/devices/.
When I attach 2, the 2nd one always shows up.
But for ...
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617
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Read Write Serial Device not Working in Shell Script
I have a USB serial device connected to my Linux VM (Ubuntu 18.04LTS). It accepts byte streams in certain format and will return some content. To read from the device, I have written the following ...
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201
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BeagleBone Slackware UART issue
I'm working with a custom made image of Slackware ARM 14.1 with kernel 3.8.X since about 3 years and now needed to upgrade kernel for cdc-acm driver and watchdog.
I've tried different kernels from ...
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UART to UART tcp/ip connection
Need to transmit and receive data(TCP/IP) between 2 raspberry through serial tx/rx pins (/ttyAMA0). Best way to do it? Better if this will be done from kernel space. Thanks!
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Debian not recognizing my ttyS0 / console redirection not working
I have a fitlet2 (https://fit-iot.com/web/products/fitlet2/) which has a serial port. I can connect to the serial port of the fitlet2 with screen from my computer (screen /dev/ttyUSB0 115200) and ...
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Mirroring USB HID signals on Open WRT through UART [closed]
The setup: a Linkit Board (Smart 7688 Duo) running OpenWRT and a generic keyboard connected on the USB host.
The goal: dumping the signal we get from the /dev/input/event0 and send it through the ...
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1
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1k
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Hardware controlled RTS on tty
I have a UART whose RTS pin is connected to an external RS485 transceiver, so that asserting the RTS pin would set the transceiver to send mode. I thought I could configure the serial port to use the ...
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2
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13k
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Retrieve file over serial without kermit and lrzsz
I have an embedded Linux on a custom board and I would like to send and receive file over its serial port.
The only way to communicate with this device is over serial and the device offers a console ...
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Utilizing UART/Serial port driver inside another Linux module/driver
I am implementing a network module/driver in Linux which uses net_devices structure. And so far I have been able to add and remove my module to and from kernel space using insmod command. Via ifconfig ...
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WvDial serial communication not working with uart /dev/ttySAC4, but works with `screen`
I have embedded system based on Samsung Artik 710 board connected to Fibocom G510 cellular modem module via UART (two lines - RX and TX).
When I try to communicate with modem using screen - modem ...
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187
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Strange serial port behaviour on Raspberry PI
I'm trying to receive serial data on a Raspberry Pi through the GPIO15(RXD) pin.
I have the following python script:
serPort = serial.Serial("/dev/ttyAMA0", baudrate=2400)
while True:
rcv = ord(...
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946
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How to Verify that a UART is Enabled on a Beaglebone Black
Question
Is the existence of a /dev/ttyO* symlink evidence that the corresponding UART device is enabled? If not, how can I check whether or not the UART has been successfully enabled?
Details
I'm ...
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3
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Failing to Enable UARTs on Beaglebone Black
Short and General Question
I'm running Debian 9 (Stretch) on a Beaglebone Black with kernel 4.9. I have tried following the instructions that I've found online, but have thus far been seemingly ...
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How can I determine if a latency is due to a driver or the scheduler?
Using an oscilloscope and toggling some pins I sometimes see latencies of 1-2 seconds from when an 8-byte UART packet is transmitted to when a blocking read returns. The packets are 1 second part with ...
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Display PXE Network Boot Process in VirtualBox Serial Console
I want to start a VirtualBox VM in headless mode and view the network boot process in the terminal via a serial console (e.g. using screen or minicom). How do I accomplish this?
Additional context ...
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What are the implications of setting the baud rate of a terminal from userspace?
Sometimes I just need to read from a serial device, so I skip the complexities of minicom or screen and just cat. However, this only works if I first set the baud rate of the terminal using stty <...
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1
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socat - UART logging and redirecting
I am currently trying to log all communication from and to /dev/ttyUSB0 and simultaneously be able to connect minicom/screen to the same device for interaction.
I tried a couple of tools and ...
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How to use UART pins on Orange Pi zero?
I want to use UART1 or 2 (see picture) on the Orange Pi zero. But when I try to open the port with screen /dev/ttyS1
Screen terminates.
I found here that I needed to add "overlays=sun8i-h3-uart1" in ...
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1
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Copying or redirecting text as input to UART, need to enforce slower bandwidth
Basically i'm completely sick of typing lots & lots of text. Obviously want type it in file, push it to UART U-Boot, then modify file, try again.
But neither Shift+Ctrl+C over screen ttyUSB0 ...
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AT91SAM9260EK upgraded kernel from 2.6 to 4.4, Serial port not working
Admittedly this is big kernel jump. 2.6 had no concept of device tree and I have not yet created device tree for my product. So just default device tree files with older form of UART settings in board ...
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Wireshark: Remote capture over UART
TL;DR: How to pipe properly over UART the output of a remote tcpdump to a local wireshark ?
I try to capture packets that flow through an embedded device to which I don't have the ability to install ...
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What is the relation between UART and the tty?
When I write programs for my own FPGA, I must select UART to emulate a terminal and for my FPGA design but I don't know exactly what that means.
I believe that UART is a basic serial transmission ...
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odroidxu4 changing default uart2 to uart0
previously thank you for watching this post.
I have tried to run linux on odroidxu4 and of course the logs are written through uart2 (this uart seems default in odroidxu4)
But what I'm trying to do ...
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613
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serial DMA pausing after 2048 bytes
I have a sama5d36 device running Debian jessie (kernel 4.1.10) with a DMA USART. To get the DMA USART to output correctly I had to turn off ECHO and ONLCR.
stty -F /dev/ttyS2 -echo -onlcr speed ...
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2
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1k
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Detect what driver is loaded for a UART connected chip?
I'm trying to detect what driver is responsible for providing the HCI interface for the Raspberry Pi 3 Bluetooth module.
Here is an equivalent of what I'd like to achieve but for a USB dongle.
user@...
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Load a Bluetooth driver on top of a generic TTL-232R->USB cable
I have one of these TTL-232R->USB cables which I usually use to access a terminal on an embedded board. They are usually detected like this:
[89702.948822] usb 2-3.7: new full-speed USB device number ...
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RaspberryPi serial port
I have a Display that I want to write to. This is possible over the serial port. When I use a USB to RS-232 Converter, that thing works like a charm. I even tried using only the RX, TX and GND wires ...
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How to configure embedded kernel to use serial line for PPP instead of TTY
I am about to start working on an embedded system which runs kernel v2.6.x.
It is configured to use its serial line as a TTY (accessible via e.g. minicom, stty), but I want to run IP over the serial ...
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Linux USART Serial Port
I'm trying to set up a USART serial port on a custom board with a SAMA5D36 processor, but I am unable to read in data from a connected device. When I run setserial -g /dev/ttyS1 I get the following ...
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Kernel parameters "console" and "earlycon" refer to old hardware?
I first found this by investigating parameters for earlycon but found that the options for console look almost identical. Both are present below and were taken from this source:
From documentation ...
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