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 weird characters

What FD, FE and FF hex values of chars represent in UART communication? For some time my UART won't work, and always returning me those three?
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1answer
58 views

Low cost UART over fibre

I need to extend an existing 5V UART over fibre for isolation reasons. Digital isolators / optos are no good as I need more isolation than that (0.1pF coupling max. from one side to the other). UART ...
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0answers
20 views

TXB0104 interface to microcontrollers

I have two controllers,LPC2138 and ATmega88 running at different power supply. LPC2138 --> 3.3V ATmega88 --> 5V I am trying to establish communication between them with TXB0104 voltage level ...
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3answers
52 views

UART communication between LPC2138 (3.3V) and ATmega88(5V)

I want to establish UART communication between LPC2138 (3.3V) and ATmega88(5V). But since they are at different power logic level, i need bidirectional level translator in between both devices. I ...
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1answer
62 views

Common Serial Port Issues

What are some of reasons that PC terminal receives garbage characters from one microcontroller? I am using BeagleBone and UART works okay, but after few transmitted command characters from PC ...
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1answer
37 views

BeagleBone Serial Communication

I have a problem seeing characters written in /dev/ttyS8 on my PC terminal with this C code: ...
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1answer
33 views

BeagleBone Black User Leds

Is it possible to set some of four available user leds to show serial port activity, like we can set it to show mmc activity?
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1answer
39 views

USART necessarily signal lines

Can an USART peripheral works (in Synchronous mode) with only TX, RX and Clock lines. And without the other left handshake signals (CTS, RTS, DTR, DCD)?
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2answers
46 views

Is UART necessary to send AT-commands to Bluetooth module?

I'm looking to alert a connected device over Bluetooth when an accelerometer detects motion. I'm thinking of using the HM-10 Bluetooth module and an ATtiny for controlling the accelerometer. The doc ...
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1answer
42 views

J-link CDC serial port driver problem

I have an on board J-link debugger on my Infineon Relax kit. I'm trying to use my J-link as a serial interface to my PC. It requires CDC serial port driver and I have installed it. Problem is that, ...
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1answer
34 views

FT230XS USB Bridge not working

I designed a small board that needed the capability of communicating over USART, so I threw in an FT230XS USB|USART Bridge. The device use is so simple that I am out of ideas for troubleshooting. ...
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1answer
61 views

Unable to receive GPS data from Quectel L80 GPS module

I have a Quectel L80 GPS module with PIC24fj128ga202. I am using UART2 to get GPS data from the module and I transfer the received data to hyperterminal, using UART1. Between PIC and PC I there is an ...
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5answers
94 views

how to convert UART voltage from 5v to 3.3v? [duplicate]

I have PIC18F4455 connected to spark core wifi chip. I send data from PIC18F4455 to the spark core by using UART. The problem is the output data of pic18f4455 equals to 5v, and the spark core accepts ...
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2answers
56 views

Input and UART error in PIC32

I have a PIC32 starter kit and I am making a program such that when I apply input 1, MCU will send this data to my PC using UART and ...
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1answer
42 views

Error in turning ON the LED using UART in PIC32

I have a PIC32 starter Kit & IO Expansion Board. PIC32 Starter Kit has 3 LEDs on baord ...
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1answer
38 views

How to communicate with 2 devices with 1 UART MCU in AVR

I am currently looking to integrate GSM SIM900 and GPS Module with Atmega32. As atmega32 has ...
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0answers
12 views

Modifying UDRx registers in the Atmel Studio 6.2 Simulator

I'm currently working on a system which makes use of an Atmega640. In order to aid debugging I'm trying to use the simulator within Atmel Studio to run the code and observe what it does. The problem ...
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1answer
30 views

Error reading data from UART in PIC32

I am trying to communicate with PIC32 UART. I am able to transmit any data but getting problem in reading the data. In PIC32 there's a function putsUART2("") which ...
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1answer
43 views

Is it possible to enable both UART and PLL at the same time on PIC18F?

I'm doing an application where I'm turning on some ws2812 LED with my pic microcontroller and I want it to talk with my smartphone via bluetooth. Now, I got the code for the LEDs from ...
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1answer
54 views

UART TTL - Which pin is 5V?

I have a board with the following connections: TMS TDI TDO RXD TXD RTCK TRST TCK GND I am trying to connect my USB UART TTL to it (I have connected the RXD, TXD, GND) but I am not sure which pin I ...
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2answers
40 views

Is RTS & CTS important in UART communcation

I am starting with UART communication in PIC32MX795F512l. This UART will communicate with PC. I was just wondering that it is important to connect ...
2
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1answer
49 views

SPI Flash memory programming with small buffer(uC memory)

I have AVR(or any, doesn't matter) microcontroller and 1 Megabyte SPI flash IC that I want to write to, I can do it already, have no problems with communication between these two. But so far I write ...
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1answer
64 views

Problem in PIC24FJ128GA202 UART?

I started to work on PIC24FJ128GA202 microcontroller. Tried samples programs like LED blink and switch, controller works fine with the coding, then I started to work on UART configured all the ...
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2answers
78 views

Single wire two-way serial communication - hardware configuration

I have several servos that can give feedback data that I want to read. The servos use special protocol so I need to use Rx/Tx pin on my Arduino Mega to communicate with them. The problem is that a ...
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1answer
44 views

Using the USART on the PIC16F877A

I am trying to use the USART to make two PIC16F877A microcontrollers communicate. When I look with an oscilloscope at the output on the TX pin of the MCU that's transmitting , I see the normal NRZ ...
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1answer
59 views

Interfacing cell phone to microcontroller [closed]

I have a microcontroller (ARM Cortex M3/4) that can interface with USART/SPI/I2C devices that I need to interface with an Android phone (Lollipop >=v4.2). My idea is to send data through USB from the ...
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2answers
294 views

Make Arduino and 89C52 talk to each other

I am trying to create a project in which I am required to make Arduino and Atmel 89C52 talk to each other. I know this can be achieved via UART but the problem is my Arduino is already using its ...
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1answer
98 views

Bitwise operation for UART, AVR

I'm trying to work on UART for AVR. After setting the baud rate registers UBRRnX, I'm trying to configure the UCSRnA register. I'm trying to set the 2nd bit, U2XO. Which is the right way to do it? ...
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1answer
58 views

TM4C123 UART is always in busy state

I am trying to configure UART0 on TM4C123G launchpad. All of my configuration registers are perfect. They've been written with desired values. But somehow, my busy flag is always 1 after first write ...
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1answer
43 views

Error interfacing GSM with Atmega32 using UART Interrupt?

I am interfacing GSM with atmega32 using uart interrupts. I am using an external interrupt which is fired when a user press a switch and uart receive interrupt to receive the response of GSM. CODE: ...
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1answer
73 views

U(S)ART/SPI/I2C - any common/prevalent/recommended connectors?

Good morning everyone! I'm currently building the board with the STM32F417 microcontroller, and I want to have separate (out-of-GPIO) I2C, SPI, UART and USART outputs on the board. But I'm lost on ...
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1answer
39 views

Restart Rx USART + DMA in STM32L1

I am using an STM32L1 on a Nucleo-L152RE board. I have to devices I control through serial running at rather high baudrates, so I am trying to enable DMA on the USART. With the code below I can launch ...
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1answer
64 views

Avoid Overrun Error in PIC18F46K80

I am using PIC18F46K80, at a baud rate of 115200, a Stop Bit of 1 and no parity. I am sending data from a C# application(Baud Rate 115200, Stop Bit-1 and No Parity) to the PIC. After send some bytes ...
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1answer
72 views

How to set baud rate 57600 with CH340G?

I'm working on android drivers (native code) for CH340G USB-to-serial chip. I've successfully tested it with baudrate 115200 and Arduino Uno CH340G but for some reason it does not work with baudrate ...
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2answers
37 views

Tm4c nested uart interrupts- does each com finishes it's run before the next one executed?

Board: Tiva™ C Series TM4C1294 EK-TM4C1294XL My program is listening to 2 UART ports (UART 3 and 7) I've encounter a problem that I'm losing some bytes received and I'm suspecting that this issue ...
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1answer
71 views

AVR sending message via UART

I want to send char though Atmega2560 to the xbee coordinator(AT mode), and router(which is connected to the computer) should receive that char. I can correctly receive messages from router -> ...
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0answers
70 views

Communication between two XBee S2 in AT mode

I want to establish a simple wireless link between my two AVR microcontroller boards; (one is ATmega8 and second is ATmega16), using XBee series 2 modules. I simply want to send some data from one ...
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2answers
90 views

Do we need MAX232/ADM3203 for UART communication with PIC32MX795F512L [closed]

I am trying to communicate UART with PIC32MX795F512L. I am really confused with this thing that we should use MAX232/ADM3202 or pins will directly commnicate. Because in some microcontroller, it is ...
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0answers
74 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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1answer
41 views

PIC18F45J50 UART remappable problem

Hello i need help with the Remappable UART communication on pic18f45j50. so here is my code compiled using Mikroc Pro for pic ...
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0answers
38 views

Multiple bytes of data not being read from PIC18F46K80

I am trying to receive multiple bytes of data from the hyper terminal to PIC18F46K80. This is my source code ...
0
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3answers
93 views

What is the maximum number of bytes that can be sent through USB-to-serial COM port at one go?

Suppose someone uses hyper-terminal to send a very long ASCII string at a COM port. This COM port is created by FTDI USB-to-serial port cable. The cable used is ...
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1answer
59 views

6Mbaud UART with Bus Pirate V4

I would like to sniff data on an SPI bus running at a clock rate of 6 MHz. I would like to use the Bus Pirate V4 for this task. The sniffing itself is supported up to 10 MHz, the problem is getting ...
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0answers
63 views

Sending data from Atmega8 to Android through HC-06

I am building up a communication between Atmega8 and Android device through HC-06. The uC can read the comfortably. But when it sends data the received data is garbage. The baudrate of working UART is ...
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1answer
133 views

Why ARM Cortex M0 prints incorrectly Hello World on UART?

I am new to ARM CORTEX M0. I am trying to use the Tx pin of UART as debug port. If I use the XDS200 debugger to step through the code, I am able to see the characters and I can see "Hello World" ...
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1answer
83 views

Contiki: Serial Line IP via SPI

I am working on Contiki's cc2530 port (customizing for my custom radio). I do not unserstand how can i make SLIP work with SPI? I understand that SLIP is similar to UART (it is UART without parity, ...
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1answer
51 views

FT232RL TX/RX Direction

I want to basically embed an FTDI cable in my board to avoid confusion with the RX/TX pins, wrong cable, etc. I really want to make sure I choose the direction correctly though. I have ...
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1answer
49 views

Stm32f429 usb cdc to pc

I want to put together a simple library to communicate between stm32f429 and pc via usb cdc vcp. I noticed many examples from stm create a usb uart bridge on the mcu. I am trying to understand the ...
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2answers
96 views

FTDI UART programming (first steps)

Im currently trying to leave the arduino board aside and starting program microcontrollers on pcb boards via programming pins, im using an ATMEGA328u from this premade board, For starters im trying to ...
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1answer
32 views

Leakage current in UART RXD

I have connected a microprocessor to a bluetooth module using UART. During the sleep of my microprocessor, I measured 7.8uA flowing from uC's rxd to bluetooth module's txd. I measured 70k pull-up to ...