Questions tagged [uart]

a Universal Asynchronous Receiver/Transmitter, better known as serial port

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SPI0 and UART0 interference caused by SPI interrupt

I have a raspberry CM3 running a custom Linux version created by buildroot (kernel: 4.19.44-v7). The CM3 is configured to be part of a measurement system that is used on a quad-bike (so a lot of ...
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Raspberry Pi and LIN Bus

I want to implement a LIN Bus using a Raspberry Pi 3. The RPi will be the master controlling slaves on the LIN Bus. My idea is to use the Raspberry Pi UART, but I am not sure to what extent this ...
A.Chaalane's user avatar
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Disable onboard Bluetooth device and remap UART0 on Windows 10 IoT Core

We would like to use Gertbot card on Raspberry Pi 3 to control motors and to read distance sensors. For that, serial communication using UART0 on GPIO pins 8 and 10 is required. Observing Raspi serial ...
Petri K's user avatar
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Raspberry Pi 3 Bluetooth Baud rate

How do I increase the available baud rate of the bluetooth module for the Raspberry P1 3 model B? I have tried editing the /boot/config.txt file with: init_uart_baud=1000000 init_uart_clock=16000000 ...
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RPi 3B+ & Yocto & U-Boot : free UART pins to be available for a RS232/485 HAT

I have the following hardware/software setup: Sferalabs StratoPi Base (Raspberry Pi 3B+ with a HAT for RS232/485) Distro built with Yocto and meta-raspberrypi on thud branch U-Boot SysVinit I want ...
Carton_'s user avatar
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C# .NET Core application cannot open serial port

I'm running a .NET Core application on Raspberry Pi OS (32-bit Debian). pi@raspberrypi:~ $ cat /etc/os-release PRETTY_NAME="Raspbian GNU/Linux 10 (buster)" NAME="Raspbian GNU/Linux&...
thinwybk's user avatar
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pySerial - UART - Determining when a message has actually been sent (callbacks?) (RTS/CTS hacking?)

For reasons (explained at the end of the post) I need to have a pin change state immediately as the UART finishes outputting a set of bytes. I'm using pyserial & pigpiod on a RPi3B+ and bluetooth ...
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Mini-UART on RPi 3 and earlier loses synchronization if parity bit used

I have a sensor which every 1 second spits out a 32-character serial stream at 9600 baud. I hooked it up to the mini-UART pins on the GPIO connector. What I saw was bad data. After staring at the ...
Larry Klein's user avatar
2 votes
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How can I reconfigure the UART on the fly?

I have a Pi Zero with Raspbian which I'd like to use as a logger device with WiFi (it's not a W, I'm using an external WiFi stick). I need the UART to communicate with a microcontroller but sometimes ...
bmann's user avatar
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Toggle UART (enable_uart=1) without rebooting

Which pins can can I manually toggle to enable or disable UART on a Raspberry Pi Zero or 3B+ without rebooting? As I understand, /boot/config.txt is parsed before Linux is started, but I don't mind ...
Petrus Theron's user avatar
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How do I test if my UART port is working? Simple example... loopback-test

I am working on a NMEA(GPS)-datalogger for a drone. I followed the tutorial from fishandwhistle and createt this script: #!/usr/bin/python3 import os, time, sys, glob, datetime, syslog, pynmea2, ...
Hans Jürgen's user avatar
2 votes
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4k views

Raspberry pi 3 uart not working

I've done almost any tutorail I found in the internet, but I cant get successful communication with uart in RPI3 Ubuntu Mate. I've added enable_uart=1 and dtoverlay=pi3-disable-bt and core_freq=250 ...
Muhamad Jafarnejad's user avatar
2 votes
0 answers
419 views

Lost Serial on Pi3 running Pixel

I have just upgraded to the latest OS Raspbian Pixel and my serial connection has stopped working. I know that the hardware is configured correctly as it worked pre-update. I have updated to the ...
Ray Troy's user avatar
2 votes
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1k views

u-Blox SARA and ModemManager

I have a u-Blox SARA-U270 device connected to a Raspberry Pi 3 via UART GPIO pins, that I am trying to use for a 3G connection as a backup. I would like to manage this via NetworkManager/ModemManager ...
Andrew Mack's user avatar
2 votes
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894 views

How can I make the ITEAD PN532 work on the R-Pi via UART?

I have used the Adafruit PN532 before on the R-Pi (A and B+) via UART and it works just fine but I haven’t been able to make it work for the ITEAD. The ITEAD supports I2C, SPI and UART. On this link, ...
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Using Raspberry Pi with Arduino GSM/GPRS Shield

Raspberry Pi Model B GEEETECH Arduino GPRS Shield V1.0 (bought from: bit.ly/1G0KYR7) ^ Similar somewhat to: Seeed's GPRS Shield V1.0 | Link: seeedstudio.com/wiki/GPRS_Shield_V1.0 (has more ...
Michael Sh.'s user avatar
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Receive data from uart with Raspberry Pi mono c#

From today, after updating libraries Mono C# on my Raspberry Pi Rev 2 Type B (wheezy), the communication via serial no longer works, it seems to me very strange, because yesterday with the same ...
stfno.me's user avatar
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Redirect U-Boot console to UART2 in RPi 4B

This is similar to this question, but for different hardware and with some things already tried. My ultimate goal is to have bluetooth on UART0 and debug on UART2. I use RPi 4B and need to redirect U-...
Adam Trhon's user avatar
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Transmitting Serial data via Wi-Fi from Raspberry Pi to Wi-Fi Module

I previously built two separate projects for sending/receiving data between an Arduino and a Raspberry Pi 3. One transmitted via Bluetooth (HC-05 Module on the Arduino-side to the built-in BT module ...
JoeBro391's user avatar
1 vote
0 answers
125 views

TF03 LiDar Distance Sensor UART Issues with Pico

I'm having issues getting a pico to receive data from a Benewake TF03 Rangefinder LiDar distance sensor. The User guide/Documentation mentions it working from 5-24V and it uses low voltage (3.3V) TTL ...
Isaac Flaum's user avatar
1 vote
1 answer
507 views

How to Access Terminal Over Serial Port in Raspberry pi 4

I'm trying to Read and Write over Serial Port to Terminal in Headless Linux That I Installed on my Rpi4. is That even Possible? is so, how?
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Pi Zero V1.3 miniuart not working

Ive got a bare metal project that has been running on Pi 3 without problems, i want to start moving it over to the Pi Zero, i have a V1.3 Pi Zero (not W) here so started with that. Ive stripped it ...
Adrian Brown's user avatar
1 vote
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311 views

UART3 RX/TX mode doesn't work for Raspberry Pi Compute Module 4!

I am using Raspberry Pi Compute Module 4: Linux raspberrypi 5.15.82-v7l+ #1605 SMP Thu Dec 8 15:21:38 GMT 2022 armv7l GNU/Linux # lsb_release -a No LSB modules are available. Distributor ID: Raspbian ...
User's user avatar
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RPi 2 GPIO UART can send data to Teensy, but can't receive

I am trying to send data between RPi 2 (model B) and Teensy 3.2 using the GPIO on the Pi (GPIO 14 and 15) and Serial2 on the Teensy (pins 9 and 10). The problem is, I can only send data from the Pi to ...
Ron's user avatar
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1 vote
1 answer
584 views

Raspberry pi 4, UART4 and SPI0

Raspberry pi 4 has 4 usable uart ports, uart 4 with rx in gpio 9 and tx in gpio 8, share rx pin with SPI0 miso0 pin. I would like to use both peripherals no ate the same time, but in different moment ...
Jefferson Alexis's user avatar
1 vote
0 answers
390 views

Having issues interfacing SPS30 with Pico

I am trying to interface SPS30 via UART, but I am not able to start the fan. I am getting some response but it won't match any possible response from the datasheet. Using Micropython. Below is the ...
Robot's user avatar
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1 answer
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How to clear UART RX error for pico (RP2040)?

While working with a RPi Pico UART RX routine in C using pico-sdk, I have realized that uart_get_hw(uart0)->rsr; reports an error - that is, it has a value different from 0 (in my case 13, which is ...
sdbbs's user avatar
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1 answer
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Missing dtbo overlays in Yocto build for Compute Module 4, what do I need to get them added?

So I have a problem that I have half solved and was hoping someone would know how to solve the rest. So yesterday I encounted a problem that I asked and partially solved at the link below. CM4 Uart 0 ...
HelloWorld's user avatar
1 vote
0 answers
170 views

My DT overlay doesn't work

I'm trying to activate the miniUART with RTS and CTS signals (on an RPi Compute Module). For this purpose I've created an overlay: /dts-v1/; /plugin/; /* Enable /dev/ttyS0 with RTS and CTS signals ...
Daniel's user avatar
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338 views

redirect U-Boot Console to UART4 in rpi cm4 board

I am using Raspberry pi CM4 for my project. The Hardware is designed in such a way that i need to redirect all the debug messages coming through serial UART0 to UART4. I Use U-Boot as a boot loader ...
vivek's user avatar
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1 vote
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2k views

How to enable DMA for all UARTs in RPi 4?

Using RPi 4B, image 2020-08-20-raspios-buster-armhf-lite.img with kernel 5.4.51-v7l+, but tried also to use Ubuntu Server with custom compiled kernel 5.4.83. I have trouble getting UARTs working with ...
Mazi's user avatar
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1 vote
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92 views

Can four UARTs plus either an SPI or i2c connection be used at the same time on a Pi 4?

Since using 5 UARTs at the same time on a Pi 4 is apparently not possible, is there any reason why 4 UARTs plus either an i2c or SPI connection at the same time (one or the other) would not work?
YWE's user avatar
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How can Rpi4B use multiple on board and USB based UART / serial ports?

there. I am trying to use rpi 4 to access my own device through UART. However, the number of UART port isn't enough for me since I'm trying to access more device in same time. Thus, I want to know if ...
黃政鈺's user avatar
1 vote
0 answers
178 views

reading from 2 UART at the same time

I am reading values from 2 UARTs. i want to read at the same time (without time shift between the 2 UART) the values they send in order to add them. How do I achieve that? I am searching on google, I ...
just_learning's user avatar
1 vote
0 answers
847 views

Raspberry pi 4 model b uart is unable to write

I got some questions about uart in raspberry pi 4 model b. I used to run my program in rpi 3 model b+, but everything went wrong when I tried to do the same thing on pi 4. First of all, each time I ...
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1 vote
0 answers
400 views

RPI Serial Communication through USB

I am trying to set up serial communication between my Raspberry Pi Zero W and my PSoC. I want to do this through a normal microUSB to USB 2.0 converter cable, which looks somewhat like this picture: ...
user54952820's user avatar
1 vote
0 answers
177 views

RPI3b+: UART serial communication problem

I have my RPI setup to communicate serially with another board. Currently, I have a usb to serial converter which is plugged into one of the RPI ports. This works well but, I want to take that out and ...
Jean Valjean's user avatar
1 vote
0 answers
254 views

Uart Communication pi to pi

I first connected two raspberry pi, one is Model 4B(transmitter) and another Model 3 B+(receiver) via Uart. Done all uart enable steps (sudo raspi-config>Interfacing Options>Serial>Serial Interface is ...
Jashanjot Kaur's user avatar
1 vote
0 answers
189 views

USB ports for 4G modules disappears after resetting the 4G module

I am using the EC25 quectel LTE module with Raspberry Pi 3 Model B. I can access the internet using serial pins of raspberry pi i.e. UART Tx and Rx. I can find ttyUSB[0-5] in ls \dev. I am sending AT ...
theashwanisingla's user avatar
1 vote
0 answers
603 views

Getting garbage characters on RPi3 UART console, logs on HDMI are perfect

I have searched a lot on internet and tried all suggested solutions like criss-cross connection, checking loose connections, changing baud_rates and using GND connection for UART, but nothing seems to ...
Naveen's user avatar
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165 views

Could not read all bytes from /dev/ttyS0

I try to send some data to a module which connected via UART /dev/ttyS0, I send a standard command to module and module send me back a 13 bytes acknowledgment, but the first 5 bytes of ack not ...
Parsa Karami's user avatar
1 vote
1 answer
4k views

SIM800 GSM Module To Raspberry Pi UART Serial Communication Problem

I am new to Raspberry Pi Zero and I want to connect it with a GSM module for GPRS connectivity. I bought the SIM800A GSM module but its LED is not even blinking one single time. I am able to turn on ...
M.Shah's user avatar
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1 vote
0 answers
978 views

Interfacing SIM800L with PPP [LCP Terminated by Peer]

I am using SIM800L, and managed to interface it with RPi3. After successful configuration on /etc/ppp/peers/rnet, my file looks like this connect "/usr/sbin/chat -v -f /etc/chatscripts/gprs -T ...
Sibidharan's user avatar
1 vote
1 answer
763 views

Serial commands over Ethernet RPi 3b

I am trying to send LinBus protocol serial commands over the ethernet port of my Raspberry pi to a linear actuator connected on the other end via ethernet. Currently, I am using pyserial script to ...
Jon Head's user avatar
1 vote
0 answers
120 views

Do Rpi3 UART devices inherit their device ID from the on-board UART0 controller (GPIO pins 8 & 10)?

I am working on a device prototype which reads load cell data to an Arduino which sends the load cell data via (hardware, not USB) Serial to the Rpi3 running Win10 IoT. The communication link ...
Matt's user avatar
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1 vote
0 answers
61 views

UART 0 PCLK not registered (pi 3)

I'm using a rpi 3 and so to use the UART 0 I had to disconnect the bluetooth from it: enable_uart=1 dtoverlay=pi3-miniuart-bt dtoverlay=midi-uart0 in /boot/config.txt It works great but now at ...
Max Circle Fade's user avatar
1 vote
0 answers
152 views

Adafruit Ultimate GPS with Rpi 3 "Permission Denied"

I am trying to connect an Adafruit Ultimate GPS to my Raspberry Pi 3 and read data from it using the WiringPi Serial library. I have set the serial connection up and removed the serial console through ...
mike's user avatar
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1 vote
0 answers
331 views

What is (typically) GPIO's UART RXD input impedance in a RPi 3 Model B?

I'm sorry if this is a trivial (or already answered) question, but I really couldn't find an answer on the web. I'm trying to connect an AVR board, which operates at 5V, to a Raspberry Pi 3 Model B's ...
Maurizio Carcassona's user avatar
1 vote
0 answers
58 views

USB Dongle not working if it's connected by default to my Raspberry Pi

I have a USB Dongle That I communicate with it using UART commands. So if I connect my dongle after starting the system I can send commands and I'm able to receive info, But if I leave the dongle ...
Amine Harbaoui's user avatar
1 vote
0 answers
2k views

Can't Login to Pi0 console from Pi3 B+ via UART Serial USB-TTY Adapter

I am new to RPi's so bear with me please: I am trying to log in to the Pi0 console via sudo screen /dev/ttyUSB0 115200 but I just get a blank screen. Ouput of dmesg | grep tty: [ 0.000000] ...
Sterling Butters's user avatar