Questions tagged [rs232]
RS-232 is the electrical standard used on most serial ports. Note that this standard is a +/- 15 volt system and requires a FDMI converter to make it compatible with TTL logic levels.
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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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How to prevent power transfer (reverse current) between two DE-9 RS-232 cables? [closed]
we have two USB host devices that communicate with each other and as part of the chain, we are using two Serial to USB cables to connect them, like this:
We are not 100% sure as this happened at a ...
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ESP32-S3: Serial stops working after a random period of time
I am using a ESP32-S3 Dev Kit (Arduino code) connected to a MAX3232 to read data from a solar inverter. I am facing a strange problem as follows:
The UART (Serial1, ...
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What to look for when selecting a cable for transmitting multiple types of signals in a moving environment
I'm working on a device that involves transmitting data between a microcontroller and an IMU device housed on a different PCB. The two are connected via a cable using a mini DIN connector. I've ...
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MAX3232 ESE+ Not Working but ST3232C and MAX3232 Working on same PCB
I have designed a pcb for Rs232 to TTL, UART converter for using ESP32. I will control an LCD with ESP32. Some IC's (MAX3232 ESE+) heating at the first start. and not working just heating and heating. ...
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When designing a product that uses a DE9 connector, is it normal to just classify it as an RS-232?
Question:
When designing a product that uses a DE9 connector, is it normal to just classify it as an RS-232?
Background:
I am seeing a lot of references to RS-232 while reading engineering documents ...
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Can I Use RS232 Library For RS422 in PIC Microcontroller?
I have this project where I have to use RS422 and Max485 serial communication.
The task is simple: The input from 15 buttons should be send to PC by RS422 using PIC18F4620.
I have no experience in ...
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Isolation on RS232 bus
Is there any "simple" way to get (1500V) galvanic isolation on RS232 (just RX and TX)? By isolating, I mean than I have 2 different grounds on each side of the insulation barrier.
On side A, ...
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Can RS-232 DB-9-compatible cable be used as a physical medium between two CAN bus DB-9 ports?
Note: I am not talking about connecting an RS-232 device to a CAN bus!
I am strictly interested in reusing a RS-232 cable with two DB-9 connectors (one male and one female) to connect two CAN devices, ...
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Unable to clear faults on Monoblock via RS232 command: Need help decoding serial messages with Arduino
I recently purchased an XRB160PN192 Monoblock with a known fault of high voltage (HV) for a low price to use in my graduation project. After reading the user manual, I found that the HV error, along ...
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Modbus ASCII messages delimiter
I need to implement Modbus messages reception over UART. For RTU it's easy because UART on my uC has configurable idle receive line detection. However, for ASCII the task is tricky - the delimiter is ...
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RS232 DCD over Serial-USB Adapter
I've been reading about PPS in linux and GPS synchronization.
I stumbled on some sources recommending using a USB GPS, I'm nto quite sure I understand how the interrupt signal is passed through.
The ...
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Why does the data observed on a UART/RS232 bus look different between a logic analyzer and an STM32 Debugger?
I'm trying to communicate with a BNO055 using an STM32L552ZET6Q microcontroller via UART. The BNO055 is on a separate board, and connected to the STM32 via a 1.5M cable. Additionally, there are ...
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Capturing serial output from PuTTY
I have a microcontroller set up to capture serial data via RS-232 so that I can debug directly and view registers, variables, etc. I am using PuTTY through a USB to RS-232 converter to send data to it ...
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Convert RS232 signal to I2C/CAN/MAVLink signal
I have an airspeed sensor that outputs a RS232 signal: https://www.aeroprobe.com/micro-air-data-system/. I want to connect this sensor to the Pixhawk in order to use the data for my controller ...
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How to correctly wire RS 232 when data and power inputs are from different devices?
I'm trying to get nav signals from my flight simulator to my hand held GPS. The GPS (an Aera 796) sits in a cradle with bare wires coming out that would normally be tied into devices and power behind ...
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Must RS-232 devices use the same logic level?
I want to interface a microcontroller with the RS-232 COM port of my PC.
My PC uses a 75232G IC, which uses +/-12V logic levels as per some multimeter tests.
Currently I'm planning to use the ...
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On a (Windows) PC, can the TxD pin on COM1 be bitbanged? If not, why not?
In this question:
Why usb to serial port converter can’t program avr microcontroller?
Cornelius claims:
"DTR and RTS are the only pins of the serial port that can be bitbanged."
But is that ...
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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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How do I know if it's RS232 levels or TTL levels
I have a random device: GT MEDIA V8 Finder Pro. I would like to communicate over its console port.
Here are some pictures of its mainboard. Here is the area around the console connector:
I have no ...
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How to develop an ESD circuit protection
I am trying to solve what seems to be a common issue of the MAX232 chip getting burned by electrostatic interference. To solve this issue alternative chips are available on the market such as the ...
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Switching RX and TX of RS232 level shifter
I am using a RS232 level shifting board with a raspberry pi. The board is connected to the pi using VCC, ground, RxOut->UART-Rx and TxIn->UART-Tx.
I try to avoid buying a null-modem-cable, can I ...
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How to switch between multiple signals
I have a board that has a MAX232 and a MAX485. I want to switch between these peripherals' RX/TX signals which connected to Arduino. How would I achieve this?
I am definetly not knowledgeable about ...
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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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MAX3232: change output to be positive only
I have an existing product with a spare RS232 port on the rear panel. This is connected in the standard way to a MAX3232.
I would like to use this to connect to another device that is TTL level, so I ...
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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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RS232 LED matrix programming
I managed to pick up two 16x64 unbranded LED matrix for next to nothing. My son has autism and absolutely loves LED scrolling signs so I thought it would be a nice project to build for him. They have ...
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When the RS232 call is canceled, which pin transmits it to the DTE?
According to my research: When the call to DCE in the RS232 protocol arrives at the ring indicator (9) pin is activated and information is sent to the DTE. Let's say we talked for a while and we had ...
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Force RS-232 DTR active
I have a vending machine that has a RS232 port. I'm trying to get data through another protocol called MDB to get telemetry data, but I really think that it only outputs data through MDB if the RS232 ...
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How does using an RS232 splitter affect the data transfer speed?
I am converting digital data into an analog signal through the RS232 PCIE card I added to my PC. I have a desire to collect data from up 8 different RS232 connections and I am looking into using an ...
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Is it possible to use an RS232-USB cable (with an FT232RL chip) for RS485-USB communication?
I have a standard RS232 to USB cable found on Amazon.
It does not work out of the box. This is what I expect since RS232 uses a ground reference and RS485 uses a differential between the two data ...
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What standard defines the number of stop bits in RS-232?
There is an option in many terminal programs or ICs to set 1 stop-bit, 2 stop-bits or 1.5 stop-bits. Is there any standard that says the RS-232 can have only 1/1.5/2 stop-bits but can't have 0.5 or 3 ...
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How is the output of this circuit RS232?
I'm trying to design a multi-channel USB-RS232 adaptor (inspired by this) to go into a larger design. After hunting a little, I found this schematic in the datasheet for FTDI's FT4232, which is the ...
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Transmit error on CAN bus with MCP25625 boards
Setup: CAN bus with 2 nodes each with a microcontroller (CC26X2R1 LaunchXL evaluation board) and CAN controller with an integrated transceiver (MCP25625 click board).
I used the libraries for the ...
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How to use MAX3232 RS232 to UART converter with ESP32
I want to use max3232 IC with ESP32 to connect Topway HMI display. I decided to use ESP32's RX2 and TX2 pins to connect max3232. So I've tried to make this circuit (from here) for my PCB. But ...
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How can I use a serial port to listen to if a toggle is switched?
Using a PC and writing some software I want to detect if a user toggles a small electric switch with as little external hardware as possible. I was thinking that maybe I could use a USB to serial ...
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Transmitting an RS232 Signal over Wireless/RF. Can this be achieved? [closed]
I have an idea I am trying to implement and I want to know if this is possible and feasible.
I have a Barcode Scanner device that gets connected to a PC with a DB9 COM port. Using this connection and ...
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Can you identify this digital signal? It looks like a UART signal and can't figure out the baud rate
I'm trying to read the signal between my quadcopter's camera board that is controlled by an android app, and the rotor control board in the drone.
There are two boards in the drone: the camera board, ...
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MCU to talk to 5 (or more) serials
I have a project where I need to talk to 5 devices over serial (RS232 to be precise).
At 57k Baud. With a polling frequency that is as high as possible.
The first step is probably to convert from ...
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Serial2.write not working on ESP32
well I using topway brand HMI display it is very easy to use with Arduino nano or UNO with rs232 converter. this my converter:
. for example this code is writing "63" number on display. it ...
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Raspberry PI4 and RS232 adapter cable: how to send serial commands
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 (...
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Why is my serial connection transmitting slightly incorrect characters?
I have four configurations I'm testing, and one of those configurations is showing symptoms of incorrect transmission in one direction only (from my laptop terminal to the server).
Direct connection ...
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MAX232 IC does not convert to and form RS232 levels
I made a simple circuit to read data from RS232 lines and print data on different RS232 lines. This is the IC I am using: MAX3232EIDWG4. The IC fails to convert the CMOS to RS232 level logic.
I am ...
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Who decides the timing in the async serial communication based on UART + RS232?
According to here, UART is a hardware device that implement the asynchronous serial communication protocol.
And according to here, RS-232 defines the electrical characteristics and timing of signals, ...
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How are the bits transmitted over the wire?
This should be a basic but fundamental question.
Suppose I have a source and destination communicating over a wire.
Source wants to send bit stream 01101 to ...
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RS-232 Crossover, and Protection against shorting two TXD lines
I'm in the process of designing a USB to RS-232 converter for communication with some existing boards, and I ran into two problems.
First Question
I need a way to programmatically reverse the TXD and ...
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RS-485 communication with slave microcontrollers driving addressable LEDs?
I am trying to figure out how to achieve the master-slave configuration shown below.
The aim is to individually address an array of 150 mA LEDs, driven by the IS31FL3265A PWM driver. For this specific ...
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Arduino NANO heating issue
I am trying use a HMI display with arduino NANO. I am powering arduino and hmi display ( topway 5 inch smart display ) with 9 volt adaptor. everyting works fine. but if I plugin the Tx, Rx pins which ...
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RS-232 returning question marks when reading serial port
I have a question about receiving responses from a machine using PySerial's read method.
I am new to this forum as a chemistry student with minimal experience with ...
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