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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STM32 UART Single-Wire half-duplex communication

I tried to make single-wire half-duplex communication in UART using the STM32F103C8 controller. In single-wire half-duplex communication, a TX pin is used for transmitting and receiving the data. I ...
10 votes
2 answers
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What vendors make anti-counterfeit drivers for USB-UART ICs?

In the USB-UART ICs field the best known warrior-with-counterfeit is FTDI with the FTDIgate-2014 and FTDIgate2.0-2016. Do other vendors (like SiLabs, Prolific, Microchip, Cypress, MaxLinear or Nanjing ...
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STM32 USART RX with DMA

I'm trying to set up UART communication with DMA using the STM32F103C8 controller. I'm trying to receive data with DMA, but I can't receive data continuously. Can anyone correct me if I made a mistake?...
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MCP2221A and ESP32-S3 Auto Program circuit?

I am currently trying to make my own development board but have run into a bit of a pickle. I want to be able to Auto Program the ESP32 since pressing a button each time is not something that I would ...
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Communicate serial data with ethernet on Xilinx

Is it possible to communicate serial data traffic via ethernet (usually we use uart-usb for that purpose)? I am talking about Xilinx Ultrascale+ based board [ZCU102, Avnet Ultrazed.]
7 votes
3 answers
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Protecting UART

I have a UART that I'm trying to protect from a few different fault conditions, including short-to-rail (12V), negative voltage, and ESD. I'd typically use TVSes to protect against ESD, and a clamping ...
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1 answer
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Can't connect (no TX or RX) through UART on some devices to SIM7600

I have 3 devices: An UNO 5v (non-genuine) An SMS hat/shield device SIM7600G-H 3.3v to communicate with via UART AT Manual: https://mt-system.ru/sites/default/...
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ESP32-Mini-1 Power management and UART communication

I am designing a board that incorporates an ESP32-mini-1. I'm able to connect to the chip via UART, but programming the chip fails with an error: ...
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Parasitic Power from UART possible?

I have a small device that has a TTL-level UART interface, the signal is fed into a Schmitt trigger, which is then used in a small IR-LED. An IR Sensor is also attached to a Schmitt Trigger, via a FET ...
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Integrate microcontroller to one UART which is used

We have a sensor with UART interface (baudrate 115200). Sensor sends data at 1 Hz. We connect it to Ebyte E32-868T30S RF module to send sensor data. We configure the RF module before assembly and can'...
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FT232 UART connected with a light sensor BH1750

I want to read serial data by a python script from a light sensor. I have the light sensor BH1750 and a USB-TTL Chip (see image). I have no idea about electronic hardware. Could someone tell me how I ...
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Framing Error upon LPUART enable on STM32 NUCLEO-G474RE board

In the board's default configuration, LPUART (PA2/PA3) is connected to the debugger MCU to be used as Virtual Com Port (UART via USB). So the Rx-Tx lines only go directly to the debugger MCU and do ...
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Problems in UART communication using Nexys 3 board

I am trying to send 1 byte of data from my Nexys 3 board to my PC using UART communication. The problem is that whenever I try to view the data on RealTerm no matter my input (hard coded into the code ...
-2 votes
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Sharing the power lines of different USB ports together [duplicate]

I am designing a PCB (picture 1) for a private proof-of-concept project where: (1) I will be using 3 UART ports of a microcontroller, each connected to a UART-to-USB converter (picture 2) and a fourth ...
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Load testing battery packs with specific BMS communcication protocol

I bought a cheap Chinese battery load tester (this one) to measure the capacity of e-bike battery packs (mainly 36 V packs). Many e-bike batteries are so-called 'dumb' batteries: you can simply draw ...
-1 votes
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UART causes ATMEGA to hang

I have encountered some issues with UART of Xbee module when interfaced with ATMEGA. Whenever I enable UART for communicating with XBee Zigbee module with ATMEGA2560. ATMEGA2560 hangs. No operations ...
-1 votes
2 answers
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Is it possible to transmit/receive 16 bits in single symbol with the UART?

In the "Universal Serial Bus Class Definitions for Communications Devices" document there is the "Class-Specific Request Codes" table. In this table there is the GET_LINE_CODING ...
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UART not sending correct data in STM32

I have to send data by UART1 from my STM32F429. The problem is that the data is not sent correctly. I debugged and I got this. For testing I want to send ...
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1 answer
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STM32 UART with DMA

I'm working on firmware for an STM32F103 which is communicating over RS232 at 9600 baud. I need to transmit and receive the data by using UART_DMA method. For transmitting the data, the DMA register ...
1 vote
2 answers
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What is the STM32F103 USART oversampling value?

There is the stm32f10x_usart.c file in the STM32F10x SPL. This file file has next strings ...
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Can I program a TS87C51U2 with a UART? With which programmer can I program it?

I have an Atmel TS87C51U2 8bit microcontroller with dual UART. I want to program the IC with a serial to USB module (TTL) or with an Arduino. Is it possible do this? Which program do I need?
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Can a PC side software detect that a com-port receive a single stop-bit instead of double stop-bit? [closed]

Let's say we set the com-port settings on the PC side with double stop-bit. And then we set the com-port settings on the device side with single stop-bit. Can we detect stop-bits mismatching with ...
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1 answer
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Connecting USB to TTL adapter with sensor node

I'm currently trying to connect a sensor node's board via a UART. These are the board's connectors. Below is the USB to TTL module I bought. How would I connect these two? RX, TX and GND make sense ...
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Best desoldering technique for reverse engineering, or maybe UART

So I'm trying to play with an EPS motor. I was able to get it to this stage while still functioning (can bus still alive and motor spins), but I want to see what processor is uses and see if I can ...
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How to prevent damage when swapping wires?

For an application with UART that I am working on, it is very easy to swap wires. Generally speaking, I have 4 wires: TX and RX for UART, and the 2 supply wires (VIN = 230V AC and GND). What is the ...
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Why are the diodes used in this fashion for the RX and TX lines? They seem to be reverse biased

The diodes seem to be reverse biased, which doesn't make sense. This is from the Olimex Ethernet EVB.
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3 answers
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CAN controller with UART interface IC?

Recently I have new request to add CAN interface for communication, but there is no CAN interface in current MCU. Then I found I can add a CAN controller with SPI interface to achieve. My question is ...
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2 answers
109 views

How to bypass strong pullup on RX pin of Wemos D1 Mini (ESP8266) to communicate with UART multiplexer (CD4052)?

I have designed an extension board for the Wemos D1 Mini module, where I wish to expand to 4 available UARTs to interface with other sensors/modules. Debug is carried out by UART1 pins. For UART ...
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1 answer
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How to configure CDC (VPC) on the STM32 Nucleo F401RE board?

I am trying to establish communication between my host machine (running Ubuntu 22.04) and the STM32 Nucleo F401RE board. I only need to transmit data from the board to the host computer (only single ...
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Is it possible to use 1 UART communication in 2 different places?

I will design an IrDA circuit for Arduino Mini. Arduino Mini will connect to PC and transfer data to other PCB with IrDA circuit. On the other PCB there is an IrDA circuit designed with STM32L0 chip ...
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Health check for Lichee Pi Nano with UART

I have a Lichee Pi Nano SBC, TTL Adapter (UART) and 8 GB SD-Card. Following pins connected together: ...
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1 answer
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Pulse-oximeter USB A UART cable to a USB C data download cable required. I need the USB A UART output to interface with a USB C cable

I need to make an interface cable using a USB – FTDI to TTL 3.3V serial UART converter cable connected to a USB C plug. Could anyone help with the connection of the FTDI UART output to the USB C plug?
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I need some clarification on the correct use of a MAX3100 SPI UART chip

I have a system where I need to communicate with a TMAG5170 SPI-based hall-effect sensor chip over a distance of roughly 1.5 meters. Originally I planned to use the LTC6820 isolated SPI transceiver, ...
5 votes
2 answers
135 views

Circuit works with one phototransistor but not with another

I created a circuit board with an SFH 309 FA phototransistor that works as an IR receiver for a serial data stream of a smart meter (this works without any problems). Now I've changed the circuit to ...
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Fix clock settings on STM32F105 with 25MHz oscillator

Noob here :) While reverse engineering a CAN bus filter module: Using existing code from Github: https://github.com/EliasKotlyar/Canfilter It appears that the clock settings aren't correct because <...
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Do FTDI serial port chips use a soft UART, or a hardware UART?

I'm considering using an FTDI cable for RS-485, and I'm wondering who controls the driver enable and how. Is it in a hardware UART, a soft UART, or by the PC the USB is plugged into (very unlikely). I'...
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Disabling a MAX487 in an orderly fashion

I have a custom Arduino design with an MAX487 for serial communication. I'm currently "disabling" it for programming of the AVR by disconnecting the GND of the MAX487, but it was suggested ...
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1 answer
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EUSART with PIC16F18346

I'm trying to set up serial communication between my PC and PIC16F18346 and I wrote this code: ...
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How to identify bits on an electric signal

I am trying to read a MIDI signal. I have used a logic analyzer to look at the signal: The upper picure is the note-on signal that should read 0x90 0x3C 0x7F. The lower picture is the note-off ...
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ESP8266 only responds to first AT command

While interfacing the ESP8266 module to PIC18F4550, I noticed that the ESP8266 only responds to the first AT command that is transmitted by the PIC MCU. It will not respond for the rest of the ...
2 votes
1 answer
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PIC18F4550 USART transmission keeps repeating

I used the following code to send out an USART asynchronous transmission of a string "AT\n\r" using a PIC18F4550. ...
1 vote
4 answers
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How does a UART transmit data if we only need to send 2 bits?

How does a UART transmit data if we only need to send 2 bits? What would the data frame look like?
5 votes
1 answer
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PIC18F4550 Asynchronous USART Baud Rate

I am trying to implement a USART routine to transmit a string using PIC18F4550. I intend to transmit the message at 115200 baud rate in asynchronous mode. My PIC18F4550 is running at 48MHz using 20MHz ...
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stm32 Lora UART communication

I have 2 lora module. I want to use one of them as receiver and the other one as transmitter. I can do this with 2 Arduino uno but I want to use one STM32 board as transmitter and Arduino uno board ...
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3 answers
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ESP32 custom hardware connection to USB-UART converter

I'm designing custom hardware based on the ESP32. I'm using Adafruit's ESP32 Huzzah as a reference. In the Adafruit design, an onboard CP2104 USB-to-UART chip is used, but I will be programming the ...
1 vote
1 answer
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Serial communication in STM32 based boards

I've made a desktop application which interfaces with an Arduino board via serial ports. Now as I have completed my project in theory, I want to make a more professional PCB with a higher clock speed, ...
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3 answers
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Which MAX3232 IC's for simple UART to RS232 converter?

I am trying make a TTL to RS232 converter. I have designed my PCB for 16 pin SMD sop16 and max3232 CSE+. But when I was buying from a store (store link), I saw other types of max3232. I've bought and ...
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2 answers
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Interface for isolated UART transmission using optical TOSLINK cable

For UART transmission in a noisy environment, I am contemplating using low-cost optical TOSLINK cable with a dedicated optical transmitter and receiver, e.g PLT133 and PLR135. Is a special interface ...
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How to determine which I2C commands to execute to arrive at a desired result?

I have successfully established bidirectional communication between a featherS2 board and a Mikroe UART to I2C bridge. I do this by instantiating the address of an I2C command from page 16 of this ...
1 vote
1 answer
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UART level shifter: strange level

This is my circuit Scoping on the UART host side I have the following trace But on the device side (3.3V) I have this trace Not sure on what I am doing wrong there... Using this NMOSFET: BSD840N
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