Questions tagged [uart]
A UART (Universal Asynchronous Receiver Transmitter) is a piece of logic that sends and receives data on a serial port.
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What hardware issues can cause UART to only work with one device but not another? [closed]
I'm trying to get Waveshare SIMCOM7600G module and nRF5340DK talking to each other. The TXD/RXD from one is connected to RXD/TXD on the other. There is no flow control enabled on the SIMCOM7600 module....
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Microchip Studio, porting attiny85 usi uart code to attiny84 not working
Thanks in advance for anyone who can help me with this. So I got a copy of some code that works pretty well just using the USI as a UART for the attiny85. At the default 8 MHz internal oscillator, ...
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What is expected error rate and drop rate on ST-Link VCP USART?
What is expected error rate and drop rate on ST-Link VCP USART?
On the Nucleo STM32F446RE, my code reads the USART VCP (of ST-Link) and echoes it back. It uses DMA, FreeRTOS, and FreeRTOS queues (...
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How to receive from UART via DMA on STM32F4?
Thanks to help from this site, my code can send and receive over the STM32F446RE Nucleo UART (using the Nucleo's built-in ST-Link / VCP). I'm now trying to move the receive to DMA, and seem to get a ...
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UART Tx Shorted to 3.3V [closed]
I'm using a PIC32mx470 and trying to get the UART communication running. I was having some issues and noticed that the Tx pin has continuity with the 3.3V lines in the circuit. Is this something that ...
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How to debug a failing USART?
I have simple code which writes to the USART on a Nucleo board that is connected to ST-Link, and appears on my workstation via VCP over USB.
I'm trying now to port it to a STM32H735G-DK Discovery but ...
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Help decoding unknown data stream
I'm currently diving into the task of cracking the data stream protocol for a generator control system. There's this setup with a control box sitting next to the generator, and a remote switch in the ...
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Scoping the UART on a STM32 Nucleo
I have a Nucleo F446RE, which writes to UART which is handled by the built-in ST-Link over VCP on USB.
I'd like to be able to see the serial signals on my oscilloscope as well. There are two exposed ...
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Cannot make ESP32 communicate with ThinkerAI A9G board via UART
I want to use ThinkerAI A9G module via it AT commands, but i cannot make my ESP32 communicate with it. I have connected them but all i get is some strange random symbols. As i understand i could be ...
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Why is my voltage disapearing from esp32 to RJ45 connector?
I am working on a project where I am sending data from an ESP32 through an RJ45 cable to a DMX decoder. As far as I can tell my wiring is correct, however, I do not appear to be getting the signal to ...
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How can I make a basic BlueTooth communication between a cellphone and MXCHIP EMC3080-P module?
I'm trying to use the EMC3080-P module from MXCHIP, because it's used in some applications from ST, the company where I had the microcontroller I'm using (for example, the B-U585I-IOT02A discovery kit ...
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PIC16F UART Receives only the first byte
I'm currently working on a PIC16F18855, I'm trying to set up the communication part.
My setup is as follows:
A PCB connected to my computer via a TTL232 cable.
The PIC16F18855 is clocked at 32Mhz, the ...
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UART resistive attenuator not working
I am trying to establish communications between my Raspberry Pi 1.2b and Arduino Uno.
The Uno received the data sent by the Pi. I know this as I can see it on terminal connected to the Uno.
However it ...
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How should I debug this ARM Cortex M STM32 UART write?
I have a STM32F446RE on a Nucleo F446RE, and I'm trying to learn how to program the UART to write over the Virtual COM Port (connected to USART2).
I'm able to download someone else's code, modify it ...
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One connector pin connected to TX (or RX) and DP (or DM) of STM32 microcontroller
I have a project here that needs the STM32L432 to operate in two modes, UART and USB. It will be connected to another system via a 5 (or 4) pin connector. It operates mainly in UART mode with pins ...
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Trouble to receive data from RS485 encoder in TM4C1294
I am trying to read data from an absolute RS485 encoder Single turn "eCoder-20S". The controller is EK-TM4C1294 launchpad. I am using SN75716AP for converting RS485 to UART conversion.
The ...
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STM32 FreeRTOS UART failing to return from interrupt
MCU is an STM32L422
FreeRTOS (CMSIS-V2), 3 simple tasks, they run just fine on their own.
USART1 is configured to receive data via IDLE detection and DMA circular buffer. Again it works fine on it's ...
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I2C Addressable UART Multiplexer
I have a number of "smart" LCDs which have their own internal processor and can communicate over UART. Unfortunately I have ran out of GPIOs on my ESP32. I was hoping to find a demultiplexer ...
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How to set up RS232 UART in Proteus?
I am having difficulties sending the correct message to the hyper terminal from ATmega32 micro controller. For some reason, the MAX232 chip is giving undesirable voltage levels. I want it to give ±15 ...
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Placement of USB/UART converter for robustness and noise immunity: long USB cable or long EIA-422 cable
Consider the very common case of communication between the UART peripheral of a microcontroller and a PC, using a USB-UART converter such as are available from FTDI and others[1].
If there's a non-...
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UART vs Debug UART vs Auxiliary UART Interface
I am using Quectel EC200U in my design. This module contains three UART interfaces. The description is given below.
The module provides three UART interfaces:
The 1) main UART interface, the 2) debug ...
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Baud Rate calculation from logic analyzer
I am somewhat new to approaching this from this angle, been using serial coms as documented for many many years configuring everything from radios to network equipment. Familiar with what baud rate IS ...
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Forensic examination of a GPS Tracker Model Type: TK905-2g-V5.0 [closed]
A few weeks ago a friend of mine found a GPS Tracke Device under his car. This is scary. On top of the case there is a branding sticker "winnes". We want to know, who did this, so we need ...
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Resistance value randomly changing
I am facing a weird issue where value of resistance (0402 package SMD) is changing randomly.
I have a fully functioning board design and have multiple boards where this issue is happening on same ...
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Psoc Cypress Monitoring Capsense Button Actions
I am too new on Psoc Cypress. I have a basic aim but I could not figure it out.
Yes there is a tool to monitor capsense values in a graph etc. But my aim is monitoring ADC values of any capacitive ...
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STM32 Serial Communication Problem
I am trying to use, TX RX communication with STM32. But my code does not work clearly. Can you help me to improve the code?
Firstly I could not decide which interrupt function I should use (...
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UART line causes exess current consumption
I'm currently working on a project that involves an STM32WB55 microcontroller, a GPS module, and a LoRa module. I have encountered an issue where, when I put all these devices into sleep mode, I ...
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CO2 sensor module MH-Z19 doesn't give a proper value on Arduino Nano
What I want to achieve
Use a CO2 sensor module MH-Z19C to detect CO2 in the room using UART with Arduino Nano.
Issue
The sensor gave an unreasonable value 0 ppm. Generally speaking, CO2 in the air is ...
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Serial communication baud rate issue
I am a bit confused regarding the baud rate of serial communication.
Suppose I am sending a value of 198 to the receiver with a baud rate of 9600. At the receiver, the rate is also the same. Thus isn'...
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Can someone explain this circuit to me? Is it a voltage level shifter?
The UART_RX and UART_TX is coming from ESP32 connecting to another mU's UART Pins (LPC2131).
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UART connection to MCU [closed]
I have a UART module that needs to be connected to an MCU.
The pins are Open drains.
The input base current is 1.16mA. Output Current 96mA. Hope its fine.
Anything I missed or I need to take care of ...
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Atmega644A programming with MCP2221A [duplicate]
I was recently attempting to design a board based around the Atmega644A, and now have to figure out which USB UART to use.
I try to stay away from SMD soldering due to the lack of proper tools, ...
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USB pins and SPI pins
I'm using this WFI32E01PC module.
I've 2 questions from the datasheet.
I'm referring the table 3-1 from page 29 of the above datasheet.
I'm not planning to use USB pins of the module. Pins 4,5 & ...
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Eyeballing bus capacitance
I would like to use single-wire half-duplex UART bus to connect together two STM32 controllers and one ESP32 module. They all will have diodes on TX and share one pull-up. The wiring uses 2m of common ...
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How many UART interfaces can be used in this MCU
I want to understand how many UART interfaces can I use in this ATSAMD21 MCU.
I searched for "UART" in the datasheet to find which pins and how many UART interfaces I can connect to. But I ...
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Sampling 24V one wire serial with a voltage divider?
I would like to sample 24V one wire serial with a voltage divider, wouldn't grounding the resistors in series potentially affect the data being transmitted?
I was considering using an optocoupler but ...
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FIFO buffer in the ATmega328P
I have a problem in understanding the working of the FIFO buffer. The diagram of the USART in the datasheet does not mention the FIFO buffer, and it just gives the UDR register which acts as a ...
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Is it possible to send characters to the USART->DR register without the COM port terminal?
STM32 UART
If you send characters via COM port terminal on STM32, then the characters are stored in the USART->DR register.
Is it possible to write something in the code so that without the COM ...
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Strange.. UART accessing U1RXREG is not emptying buffer? PIC32
Not sure what's going on this PIC32 device, the ISR is only getting the first 8 characters (the size of the FIFO buffer) the first time it receives a string. Subsequent string arrivals cause an ...
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Programming Nuvoton N76E003 with UART USB to TLL Module
I have found a Nuvoton N76E003 microcontroller in spare board and now I'm planning personal project with that microcontroller. I don't have proper Nuvoton programmer dedicated for Nuvoton N76E003 but ...
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PIC Low Voltage UART
I'm receiving data from SIM800L module to PIC 16F628A.
The problem is the PIC (PIC does not receive data properly from UART).It is working in home. But in site conditions It misses
lots of data. I ...
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How to connect a full duplex line driver
I need to use two line drivers for the communication between two PCBs. I am currently using MAX3081 from Analog and this is what I see in the datasheet:
Image Source: Analog - MAX3080-MAX3089 ...
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Does a full-duplex transceiver allow to use both directions at the same time?
I would need some help with this family of line drivers: MAX3081 from Analog (https://www.analog.com/en/products/max3081.html).
In particular I don't understand if I can receive and transmit via UART ...
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I need a microcontroller with two hardware USART ports [closed]
I have a rather peculiar requirement for a project:
I need some sort of microcontroller that has two independent USART interfaces that have to be reconfigurable at runtime.
Let's call them ...
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The TXE bit in register SR is not cleared despite writing a value to register DR. STM32F4
UART
Why isn't the TXE bit in the SR register cleared?
The Reference Manual says that the TXE bit is cleared if something is written to the DR register.
It is cleared by a write to the USART_DR ...
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GPS UART NMEA output to iPhone
Working on a tracker project. Idea is this:
L80-M39 GPS (UART) -> RF Transceiver <--- distance ---> RF Transceiver (UART) -> ?
On the right-hand side, I am getting location information via ...
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How to put the XR21V1410 USB-UART bridge in 9N1 mode?
The XR21V1410 bridge can work with 9N1 UART symbols. To use such symbol format the XR21V1410 should be put in wide mode. There is an amateur example on Basic which use some magic numbers:
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How to transmit five byte data transmit in UART_DMA?
HAL_UART_Transmit_DMA call in timer interrupt handler to check the output for just now. The output is came but this is not proper output. this method for just call in to the interrupt handler output ...
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How connect the STlink on NUCLEO f401RE to communicate with STM32F4 discovery?
I have this configuration of MCUs.
I need to know how connect the STlink on NUCLEO to discovery because I need the Virtual com PORT.
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"Textbook" example of UART doesn't work on stm32f756zg. HAL_UART_Transmit() returns HAL_BUSY
I want to send a message through uart5 of my nucleo board. I configured UART5 appropriately as per https://wiki.st.com/stm32mcu/wiki/Getting_started_with_UART .
Here is main():
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