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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UART reception problem when SysTick Interrupt is enabled

I'm using a STM32F411RE-Nucleo board and generating a project with Cube MX for System Workbench. The problem is that HAL_UART_Receive function doesn't receive input ...
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506 views

clocking MSP430 UART from DCO

I'm designing a simple remote-controlled sensor. It's going to be connected with others and a master device using RS485. All it's going to be doing is transmitting the status of a few digital lines ...
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331 views

8051 baud rate calculator using 16-bit timer for software UART timing

I'm making a project in which pulsed laser beam data is sensed through many optical sensors (one sensor per port pin), so essentially, I'm going to be making 4 UARTs to sense this. Currently I am ...
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1answer
432 views

TX Polling Not Working when setting RX interrupt stm32f103rc

I was trying USART on STM32F103RC,baud 115200, sysclk 72MHz, 1 stop bit, no parity and i connected my stm with usb to serial to look my output on terminal. At first i did polling of RX and TX and send ...
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544 views

USART on STM32F411 reads junk after MCU wakes up from STOP mode

I am working on a board that uses an STM32F411 connected to a bluetooth module over USART. One of the goals is to enable Low-power consumption in STOP mode. A brief summary of the platform: The ...
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649 views

AVR interrupt setup seems to stop program execution

On ATMEGA168PA I have problems with interrupt-driven character reception over UART. When I include the line setup_interrupt() it seems that program execution stops ...
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1k views

What's up with my 74HC4052?

I am using a TI 74HC4052E to multiplex a TTL UART on a Microchip PIC32MX695F512 microcontroller. The expected behavior is for the TX and RX signals to pass through the switches unaffected; sadly ...
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373 views

pic24fj128ga310 uart not working in application, but works with PuTTY

I'm trying to connect a PIC24FJ128GA310 mounted on an Explorer 16 board with an embedded wireless module. I have been able to set up both to communicate perfectly well with PuTTY (an equivalent to ...
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1answer
8k views

LIN-communication between two STM32F4 with a standard LIN-transceiver (Hello World)

I have the following circuit connecting two stm32F4 via the SN65HVDA195-Q1 LIN-transciever. simulate this circuit – ...
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1answer
136 views

UART stop bit baud timing error

On PIC micro controller UART, Baud rate was set to 38400 (No parity,, 8 data bits), ...
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1answer
28 views

How to Receive STM32 UART echo command using HAL libraries?

I am using a STM32L Discovery board (monted device STM32L476xx), for a transmit and receive UART operation using HAL libraries. I am using a FTDI chip for serial to usb conversion as I am unable to ...
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53 views

Serial.println using Registers in ATMEGA328P

I have worked with ATMEGA328P using Arduino libraries, but new to actual register level coding. To start with that, I have written code for basic Serial.print in ...
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1answer
44 views

MSP432+BLE+ Debugger interfacing

I would like to Interface a BLE to a MSP432 microcontroller in serial. The BLE has a inbulit Atmel controller. I have a firmware for BLE in keil. Intially I have flashed the firmware to BLE directly ...
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264 views

RC filter for UART

I am working with a device. Block diagram looks like this: I was facing a noise challenge and asked a question here. I implemented the RC filter design suggested by @analogsystemsrf and got good ...
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1answer
51 views

How to avoid duplicate messages in a mesh network of mcus

I'm working on a project, where each pcb has a connector on every side, so you can connect these board in a grid. It's basically a mesh network of modules. These modules need to communicate with each ...
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77 views

How can I estimate the minimum baudrate for a given bitrate?

My circuit performs data acquisition at 250 samples/s, 24 bits/sample and transmit this information to the local host (PC) through a bluetooth module that implements the UART protocol. As far as I ...
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1answer
118 views

Selecting true crystal settings for 328P [7.3728 MHz]

I want to make a new board working with 115200 (gsm modem) UART. so I want minimum baud error rate. I look at https://cache.amobbs.com/bbs_upload782111/files_22/ourdev_508497.html table and decide ...
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1answer
255 views

PIC32MX UART Interrupt Not working

I am writing a program to send data from one microcontroller and receive the data using on another PIC32 microcontroller and display the received data on LCD. I am using UART2 of both PIC32MX to send ...
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1answer
100 views

USB UART Bridge with capability of handling fast charge VBus

I am trying to design a charging circuit which support QuickCharge but also I want to add USB-UART bridge to communicate with on board MCU. How can I establish voltage level safe communication ...
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1answer
208 views

Does not trigger an interrupt DMA when reading SPI. Last byte transaction not coming

I use DMA for reading with SPI flash using USART. MCU - master, flash - slave. I read 1029 bytes per transaction. Exchange algorithm: I activate the flash (CS = 0) I configure the DMA channel to ...
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1answer
79 views

Best way to handle 100 GPIO on AT32UC3C0128C

I want to monitor 100 GPIO pins on the AT32UC3C0128C and indicate the changes on the USART (RS-485 transceiver). In the code snippet below, I have set one of the pins as an input with the internal ...
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1k views

HC 05 bluetooth module not working with stm32

I'm trying to get a HC-05 bluetooth module working with stm32f103c8t6 module(blue pill). I used this usb to serial module to test each of the aforementioned boards and this Android app to connect to ...
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1answer
569 views

Question on UART parity check verilog source code

Why is parity_value equal to value of 1 ? check_parity verilog source code ...
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1answer
1k views

stm32f0 uart1 rx interrupt

I have stm32f030f4p6 Microcontroller and using iar Compiler , library cmsis , After confige Uart1 the RXNE , FE and CMF bits return 1 whereas not recieve or send was done if I dont set RXNE bit to 0 ...
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219 views

Half-duplex Bit-Banged Port for 8051 microcontrollers too slow?

I was looking at: https://www.maximintegrated.com/en/app-notes/index.mvp/id/3524 and it claims that one can achieve over 2mbps on a 32Mhz clock when bit-banging with an 8051. That means 1mbps on 16Mhz....
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Getting UART Overrun Error with HAL_UART_Transmit() vs HAL_UART_Transmit_IT()

On my main board I have a STM32F103ZET6 and I use HAL library V1.6 in order to program it.There is also a sensor board which is connected to my main board and this sensor sends me data through UART ...
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332 views

Sampling analog signal at 100khz with raspberry pi

I want to sample a ultrasonic wave at 100 Ksps. Currently i am using Raspberry pi and an external adc communicating with each other vis I2S at 96Khz. Since raspberry pi cannot support higher speed ...
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220 views

RXD line problem

Hi below is my setup block diagram to understand Setup description: I have two board , board 1 and board 2. Board 2 is third party board we purchase. Board 1 has on board SMPS which convert 230VAC to ...
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214 views

CP2108 with level converter txb0108 - UART communication TTL and LVTTL

My project uses four different modems (one 3v3 LVTTL(?) and three 5v TTL) for AT communication. Each modem has a UART interface (TTL compatible). For my application, i chose the CP2108 to ...
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278 views

Serial Connection ATMEGA328p

I wrote up a function to connect via UART and print a string for debugging purposes. But my logic does not add up somehow... I see the line "Random Number" printed in the console but blazingly fast... ...
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60 views

Host device data transfer to 10 slave devices

I have a project I'd like to prototype that requires a host device that can communicate with up to 10 small hand-held slaves at one time. I looked at the latest Raspberry Pi 3 and it may possibly ...
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140 views

Xbee TX pin voltage wrong when booting with UART connected

I'm interfacing an XBee PRO 900 HP with a Beaglebone Black using UART5 on the BB. I'm using the 5v interface board from Adafruit (XBee Adapter kit - v1.1) I'm have been having intermittent problems ...
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585 views

ESP8266 and ATmega328 UART communication, gets() function

I'm trying to get an ATmega328 and an ESP8266 to talk to each other over UART. In the attached minimal example, I have an LED on pin 16 (B2) that should start on and do a slow blink to show data was ...
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429 views

UART baudrate steps

I'm trying to connect 2 devices to each other based on the UART peripheral. First one support up to 1.875 Mb/s & the other one up to 1228.8 KBd. Both work correctly on the 115200 but I need more ...
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2k views

STM32 Shutting down debug session

I'm facing with a problem regarding debug session. When I start debug session, after the configuration of USART2 the debug session is closed. Keil message: Cannot access target. Shutting down ...
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41 views

XBee TX line Drop

I am using an Xbee 900HP in API mode using UART. I am transmitting a command to it using my micro and expecting a response. Based on my Oscilloscope waveforms the data i expect back is being received ...
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531 views

pic32mx220 won't enter uart rx interrupt handler

I'm kinda new to pic32 and have been trying to get the uart to enter the ISR when it receives a byte on the Rx pin. My uart setup works fine both sending and receiving (if I use blocking to read the ...
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2k views

How to troubleshoot serial communication?

I connected my computer to a RM-BR300 controller to read its data, to try and mimic its functionality in the future. I'm using RealTerm and a USB to RS422 converter for the job - here's the result: ...
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103 views

Internal Programmable ROM of CP2102 (USB to UART)

I am using CP2102 device (USB to UART) in my project. It has internal programmable ROM t0 configure product ID. I tried in there tool via USB and it works. Now, I want to programming the ROM via my ...
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85 views

Can't run 460800 baude rate on Nexys2

I have Nexys2 Spartan 3E board and I am running Ken Chapman's UART IP core, I need to transmit data to another device at a baude rate of 460800. I was successful in sending data at 115200 and 9600 ...
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324 views

FTDI2232d + TM4C1294 configurations

I posted this question before, but I am still struggling with this. I captured a schematic and others in this time so it should be more clear to see what's going on. I was given a custom board ...
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583 views

Stellaris Launchpad: UART over GPIO PIN in ASM

I want to initialize and use UART on my LM4F120 Stellaris Launchpad in ASM. I found a reference code on how to to this on this ...
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2k views

Communicate through a VPN link using Arduino Uart WiFi Module

Following describes the configuration of the system and other details. The problem is mentioned after that. If the initial description is too much or not needed, please skip it. I have a VPN (between ...
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759 views

Problem Refreshing 4-digit 7-segment display with UART on the MSP430G2553

I'm working on a program that: samples the ADC every half a second with timer interrupt sends a signal via UART on button press (port 2 interrupt) displays the ADC value to a 4-digit multiplexed 7-...
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270 views

PIC 18F4431 USART Trouble

I've been happily using a PIC 16F628A UART for some time now. I've switched up to a PIC 18F4431 chip recently but having some problems with the USART. Initially I couldn't get the transmit function ...
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392 views

Error reading characters over serial on ATmega8 using CVAVR (USART)

I am trying to program ATmega8 for testing purposes using CVAVR as cross compiler and avrdude GUI as burner. Though I am able to burn the program, I think I am missing something in the coding part. It ...
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725 views

Atmel Software Framework. Confusion with USART example

I'm trying to get the following basic USART example working on a SAM4S: http://asf.atmel.com/docs/3.4.1/sam4s/html/sam_usart_quickstart.html#usart_basic_use_case I am using a custom PCB board with a ...
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834 views

RF Link with APC220 between two PIC16F877's

I am attempting to communicate through a RF link between two PIC16F877's using APC220 Radio Transients. When the PIC UART's are connected with wires between TX and RX they communicate just fine, but ...
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2k views

Simple PIC18 USART Interrupt not working

I'm trying to implement a link between and Arduino and a PIC18F25K22. I can transmit from the PIC and read the data on the Arduino, but am having trouble going the other direction. I think the ...
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904 views

PIC32 read feedback from UART

I'm using a PIC32MX795F512H to set up a Roving RN-131 wifi module using UART. I can communicate with the device but I want some feedback whether my commands are processed or not. I basically need to ...