Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [uart]

The tag has no usage guidance.

0
votes
1answer
44 views

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 ...
0
votes
1answer
53 views

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!
1
vote
0answers
218 views

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 ...
1
vote
1answer
151 views

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 ...
2
votes
1answer
111 views

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 ...
1
vote
2answers
597 views

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 ...
1
vote
0answers
352 views

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 ...
1
vote
0answers
115 views

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 ...
1
vote
0answers
58 views

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(...
1
vote
0answers
335 views

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 ...
2
votes
1answer
2k views

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 ...
3
votes
1answer
192 views

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 ...
1
vote
0answers
240 views

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 ...
3
votes
1answer
494 views

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 <...
2
votes
1answer
3k views

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 ...
6
votes
1answer
7k views

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 ...
1
vote
1answer
41 views

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 ...
1
vote
0answers
57 views

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 ...
2
votes
1answer
712 views

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 ...
1
vote
0answers
149 views

Serial port debug application for linux [closed]

I have hex dumps of a communication protocol. And I want to reproduce this communication logic without writing a C program. What linux/unix tool is better for this purpose? I know there is chat(8), ...
0
votes
0answers
515 views

Can't write to serial port - Linux

I'm trying an app that writes to the serial port and it's not working, so I tried with this simple command using 2 terminal windows: chmod o+rw /dev/ttymxc1 stty -F /dev/ttymxc1 raw -echo -echoe -...
1
vote
1answer
842 views

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 ...
1
vote
1answer
43 views

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 ...
0
votes
1answer
318 views

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 ...
3
votes
2answers
575 views

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@...
1
vote
0answers
189 views

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 ...
7
votes
2answers
632 views

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 ...
4
votes
1answer
481 views

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 ...
0
votes
1answer
583 views

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 ...
2
votes
1answer
5k views

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 ...