Questions tagged [uart]

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

Filter by
Sorted by
Tagged with
0 votes
1 answer
587 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 ...
1 vote
1 answer
191 views

PIGPIO bit banging UART - SLR to plaintext

I've managed to read UART input by SLRO and SLR commands from pgpiod, however, SLR returns UART bit-banged data in the following format: [number of read bytes] [bytes] http://abyz.me.uk/rpi/pigpio/...
0 votes
1 answer
351 views

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 ...
1 vote
2 answers
54 views

UART (not the board itself) stopped working after connecting 5V to GND, can it be recovered?

I accidentally connected UART wires one row lower than it should be (see image): then I unplugged them shortly after that and then connected correctly, but serial console doesn't work anymore. USB ...
0 votes
1 answer
145 views

Connecting Fingerprint Scanner without USB converter

I'm trying to connect a fingerprint scanner without using a USB converter. I have it connected to pins 8 and 10 (GPIO14 and 15). I was following a tutorial but it required me to use the command ls /...
-1 votes
1 answer
30 views

Can't get the correct serial response between Raspberrypi 4 and Pico

I'm trying to make a little connection between both my Raspberry pi 4 and my Pico. Everything was ok until the pico suddenly stoped recieving what I'm sending from the Raspberrypi. Expected Outcome I ...
0 votes
1 answer
37 views

Rpi Pico receiving on multiple UARTs

Expected behavior: in hardware I connect UART of a number 0/1 to the correct Pin numbers tx/rx and get it based on that connection Actual behavior: in hardware I connected UART of a number 0/1 to the ...
2 votes
1 answer
79 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 ...
2 votes
1 answer
2k views

How to enable more uart port on raspberry pi 4 ubuntu server 20.04

I recently got the Raspberry Pi 4 for a university project. I installed Ubuntu Server 20.04 on it. Now I am trying to enable a second uart port because for the project I need to connect multiple ...
1 vote
2 answers
65 views

UART usage with Ubuntu PI3 Model B

Can someone tell me the steps what I need to do tu get a serial communication to work? I have a raspberry pi 3 model b rev 1.1 with Ubuntu Server 20.04. I need to communicate with a sensor via serial ...
0 votes
2 answers
2k views

How to enable both UART (ttyS0 and ttyAMA0) on Raspberry Pi 3b?

I've already read dozens of manuals and stack topics, but I do not figure out if it even possible run both UARTs on RPi 3B. Some tutorials advice to map uart to other pins in /boot/config.txt I tried ...
1 vote
0 answers
42 views

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 ...
1 vote
2 answers
2k views

Raspberry pi 3 reading serial port

I have a python code that reads the serial port of the raspberry pi 3to obtain GPS positions from a fona808. The code works for some time and then throws this error. Traceback (most recent call last):...
1 vote
1 answer
1k views

UART pins not reading sensor output RPI3

This is my first pi project so im a bit new at this. Im trying to connect a senseair K-30 CO2 sensor to the pi via the UART gpio pins. This is the sensor I am using: https://www.co2meter.com/products/...
3 votes
4 answers
76 views

raspberry pi voltage rs-232 (uart)

I am trying to configure a sensor with serial communication (raspberry-sensor). But i have connected my sensor to a oscilloscope see photo. I don't know if i can connect it directly to my rspberry pin ...
0 votes
1 answer
27 views

using serial port ttyAMA0 as primary port for rs485/modbus; permissions blocked

I cannot open /dev/serial0. I selected "turn on serial port" and "do not run a console on serial port" in raspi-config. The /boot/config.txt contains no reference to "console&...
2 votes
2 answers
5k views

Size of serial port read size in c

I have a Raspberry Pi 3 and I'm currently use read(2) system call to read data from serial port. At this moment, I'm reading byte by byte from port with; rc = read(uart_fd, &byte, 1); I'm ...
1 vote
1 answer
44 views

Connect several sim800l with external power supply to the uart of ip4 and floating ground

I am creating a circuit with several sim00l connected to different UARTs each with its own external power. But I'm curious if having other objects like cooler-fan connected to other GND of the rpi ...
2 votes
1 answer
3k 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 ...
0 votes
1 answer
204 views

ch341-uart converter randomly disconnects from Raspberry

I'm facing problem, with ch341 uart chip. ch341 works normally at startup for about 120seconds. After that it disconnects. I'm attaching dmesg bellow. What it could be a problem? Tried with different ...
0 votes
0 answers
232 views

Different UART behavior between ttyS0 and ttyAMA0

I'm using serial to communicate with this board (Serial-CAN-Board) on a RPi4. UART is enabled with enable_uart=1 Console over serial has been disabled with raspi-config and I am using SSH over ...
0 votes
1 answer
165 views

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 ...
-1 votes
1 answer
284 views

Slow UART communication between Raspberry Pi Zero and 4B using pyserial

I'm testing serial communication between two Pi's (Zero -> Pi 4) with Python pyserial library. I am using Zero as camera with preprocessing and sending preprocessed data to Pi 4 via UART (/dev/...
0 votes
0 answers
36 views

How to connect UART and TPM in Raspberry pi 4

I want to connect Infineon 9670 tpm 2.0 with raspberry pi 4b. TPM takes GPIO pin 1 to 26 and UART needs pin 8 and 10. So basically I cannot connect both simultaneously. (which is the requirement in my ...
0 votes
1 answer
69 views

How to connect Sim800c development board to raspberry pi 3

i bought this development board Professional Small Size SIM800C GSM GPRS Module Quad-band Development Board Module Suitable for Raspberry Pi (blue & silver) https://www.amazon.it/dp/B07NVZ59JS/ref=...
0 votes
1 answer
1k views

use GPIO and/or UART to slow initiate K-line (ISO9141-2) communication with Audi ECU

Related to this question I'm learning to use the Pi GPIO and Python serial to communicate through an IC (L9637D) to interrogate PIDs for alarms etc. I can't get past the slow initiation sequence! ...
0 votes
1 answer
699 views

Lego EV3 infrared sensor to raspberry pi 3 direct connection via UART?

I connected this sensor with raspberry via UART( I have found that this IR sensor is one of few Lego sensors that connects via UART), and make serial_read and serial_write python scripts, just to test ...
1 vote
0 answers
84 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 ...
0 votes
1 answer
192 views

raspberry pi zero 2 w: use PL011 UART and log on to linux over wifi simultaneously

Here is what I am trying to do: log on to linux running on a raspberry pi zero 2 W. But I also want to use the "real" UART PL011 (NOT the mini uart) for RS485 (modbus) at the same time. On ...
0 votes
2 answers
131 views

(Pico) USB serial connection having noise?

I'm having some trouble trying to make a simple USB IO demo to test the Pico. Apparently, the USB serial connection seems to be noisy, and always puts something into the UART buffer even though I am ...
2 votes
1 answer
2k views

Pi CM4 - Additional UART enabling does not work

I have a Compute Module 4 here, and i want to enable more UART ports The Datasheet, Page8 specifies that uart 2-5 can be enabled since their ports are not used by anything else I've run raspi-gpio get ...
0 votes
2 answers
739 views

Possible to send data from a Pi Pico via USB while running CircuitPython?

I have a question on the interaction between Pi Pico, CircuitPython, and USB. I need a way to send a data stream from the Pico to another computer where it will be received on a USB port (it's the ...
0 votes
0 answers
30 views

Raspberry pi 4, data received from UART different from USB serial

I'm new to Raspberry pi. I writing a program that send/receive data from serial. Everything works fine with the USB to RS232 cable, but now I'm testing with the UART pins to RS232, and the data sent/...
0 votes
0 answers
147 views

Why does Pi Pico duplicate and mix-up characters received over UART when programmed in C?

I have a Raspberry Pi Pico whose Tx and Rx pins are wired to the Rx and Tx pins of a Wemos D1 Mini development board. The Wemos and the Pico are powered via an external 5V power supply (common ground)....
0 votes
0 answers
185 views

How to use Raspberry Pi 4 with an USB to RS232 adapter cable over the serial port

I would like to use a Raspberry Pi4 to control a syringe pump [(see datasheet here and in particular the quick start manual on page1)][1] The connector cables I used are RJ11 from the Pump to RS232 (...
-1 votes
1 answer
58 views

Modifying what is shown in the uART

I am working on establishing user communication (one may say a basic UI) from the user's PC to my Raspberry Pi, where the RPI would accept pre-defined commands from the user via uART and then process ...
-1 votes
1 answer
130 views

Rx, Tx/UART not being detected by Pi? What is wrong?

I'm working on Serial communication between the Raspberry Pi and the Arduino, with the Raspberry Pi serving as master. I connected, using a logic level shifter, Arduino's Rx (Software Serial was used ...
0 votes
0 answers
28 views

Enable shell interface on USB but not UART

I have a headless setup running on a CM3+ board. The custom interface PCB I'm using breaks out UART0 on pins 51 and 53, and USB on pins 165, 167 etc. The USB port usually has a WiFi antenna plugged ...
-1 votes
1 answer
98 views

Turn LED off and on using I2C, SPI or UART GPIO Pin

I have project requiring several simple LEDs and buttons, MORE that the number of ‘simple’ GPIO pins. Can I turn the LED TOTALLY OFF and on using a IC2, SPI, or UART pin? Can those pins be programed ...
0 votes
0 answers
71 views

Indecipherable Characters with UART on Pi 2

I am attempting to use the UART pins on the Raspberry Pi 2 to interface with the console port on a Cisco Access Point. I've stripped an old RJ45 cable to connect the right TX, RX and GND pins from the ...
0 votes
0 answers
39 views

Conflict between UART and cv2 Video Capture

I am attempting to communicate with an Arduino through UART using an Raspberry Pi 4 Model B. The Python script is grabbing frames from a Raspberry Pi Camera Module v2, pre-processes them and checks if ...
0 votes
0 answers
227 views

Raspberry pi and nextion touch screen communication using python

I have tested several python codes to set up the communication between raspberry pi and nextion touch screen (I used TTL serial GPIO 14 and 15). Unfortunately, the communication is not stable, the ...
-1 votes
1 answer
219 views

Question about Pi3 and UART finger printer

I have a Pi3 board and a UART Fingerprint that brand is Waveshare link is https://www.waveshare.com/wiki/UART_Fingerprint_Reader but When I receive it I have totally no idea how to use pi3 to read ...
0 votes
0 answers
14 views

Update scripts on OS via USART interface and uC

I have connected CM 4 (IO Board) with STM32F103 via USART interface. My goal is to find correct way to update pythons scripts, system settings etc on my RPI OS without direct connection with board, ...
0 votes
0 answers
47 views

Can't modify UART 5 baudrate

I'm trying to communicate a NUCLEO-F746ZG with a RPi-CM4 thru the UART5. I need, at least, a baudrate >= 4000000. Using the stty -F /dev/ttyAMA2 4000000 I get the "unable to perform all ...
-2 votes
1 answer
268 views

UART make sure to prevent data loss; choppy binary transmission [closed]

If I use UART to send sensor data from a Pi Pico to another computer (received via /dev/tinyUSB0), does the "default protocol" have any sort of error correction? I guess I don't need to ...
1 vote
1 answer
2k views

RPi Zero: Two UART devices at the same time

I need to read UART data from one device, and send different data to the other device, all via raspberry pi zero. It has only one UART TX and one UART RX on GPIO pins, but I heard that it is possible ...
0 votes
0 answers
149 views

Connecting the pi to a pixhawk flight controller

I am building a drone using a Pixhawk 2.4.8 flight controller. I want to add a pi with a picam to my build. I have followed this manual for connecting the pi to the controller. Therefore I have made a ...
39 votes
11 answers
65k views

How to get more than one uart interface

Ok, I have one uart interface (TXD GPIO 14, RXD GPIO 15). I want at least one more uart interface. Possible solutions: Bit banging: Use two unrelated spare GPIOs. I understand that timing is a ...
0 votes
1 answer
144 views

How can I "test data" coming in to a Pi from an UART device connected via TTL-to-USB

I've got a Waveshare PN532 RFID reader/writer. I want to use it with a Pi 4B, but since it is already using a HAT with no free GPIO, I want to use it in UART mode, but not connecting to the GPIO pins ...

1
2 3 4 5
8