RS-232 is the electrical standard used on most serial ports.

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RS422 to RS422 and RS232

Is it good to use one UART interface on MCU, RX_UART for receiving data from RS422 receiver and TX_UART for transmitting the same data to the RS232 and RS422 transmitter? I am trying to use UART as ...
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33 views

PICDEM board and Linux connection through serial

TL;DR: I can open screen or putty session in terminal to the /dev/ttyUSB0, but characters ...
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0answers
46 views

How to upload hex file using UART communication.?

I have designed a system which will be installed in a remote location. If will further be in testing period for about 1 month. During this period, I will not be present at the remote site. So if I ...
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0answers
35 views

Autodetection between rs422 and rs232 [on hold]

I am trying to detect if signal is RS232 or RS422. Both use 2 wires, one is single-ended (rs232) that means it uses one line for voltage level in relation to GND that is used as second wire (voltage ...
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1answer
43 views

How can I send keyboard input to USB port or Serial Port?

Now, I am using Windows 8 and have made Arduino buttons to operate as an keyboard's 4 arrow keys(up,down, right and left). From this moment, I am going to send this keyboard input event out to the USB ...
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2answers
55 views

Microcontroller Interface with Modbus Serial [on hold]

I'm a beginner and I'm trying to acquire data from a microcontroller with Modbus serial protocol in order to create an interface with LabVIEW. I'm using a Prolific Technology USB-RS232 converter and ...
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1answer
42 views

Can i directly connect a gsm shield to a computer without using arduino?

Ok, i've bought a gsm900 in alexan, and what i bought was a gsm shield thinking that it is really just the same only that shield can be placed directly in an arduino. The problem is that, im trying to ...
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2answers
91 views

Send analog audio through the rs232 port of a data transmitter

I would like to convert an analog audio signal into an rs232 datafeed to send it through a data transmitter and receive it at the other end. I already have the data transmitter and receiver. Thanks ...
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1answer
62 views

Convert usb scale output to serial

I would like to convert the usb output of a scale to a serial format so I can read it through a com port. I saw this tutorial from adafruit Adafruit serial scale but that scale is not available ...
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1answer
66 views

Modbus raw data COM capture file example?

I'm attempting to use a RS232 tap to sniff a serial connection between two devices that are communicating using Modbus RTU. I'm looking for any capture files taken from sniffing a COM connection or ...
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1answer
45 views

Question about FTDI USB-to-Serial Evaluation board [closed]

The evaluation board I am talking about the FTDI EVAL232R evaluation board which can be found at the bottom of this page. It employs a FT232RL IC. What I want to do I would like to connect a USB ...
0
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1answer
56 views

RS232/RS485 Converter Circuit Receiving Problem

I'm trying to make an RS232/RS485 converter circuit. I used a circuit from http://airborn.com.au/layout/232cnv/232to485.html site and i changed some components on that circuit. Then I established my ...
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2answers
41 views

Conversion of RS232 to USB [closed]

Can anybody explain how FT232R or CP2102 or some Serial to USB converter and it magically appears as COM port on PC? I would appreciate a detailed explanation on how the conversion happens. Some ...
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2answers
61 views

Control door with RS232 or Ethernet relay

Our company use a fail safe electric bolt with a remote control for the entry door. It closes when the power is ON and vice versa. It does work normally but I want to make a hot button for the ...
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2answers
43 views

Need to get sensor data from a Arduino Pro Mini to a Arduino Mega that is about 150 feet away from each other

So like the subject line states... Need to get sensor data from an Arduino Pro Mini to a Arduino Mega that is about 150 feet away from each other (maybe slightly less) both operating at 5VDC. Do I ...
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0answers
30 views

Serial muxing RFID units

I want to mux up to 8 RFID units, the RFID units auto sends information (13 bytes) and uses RS232 interface. I will use a arduino to mux the signals and forward it to the main computer. I'm using ...
0
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1answer
94 views

UART - getting gibberish data from MAX232 with PIC16F877A mcu

I have created a serial communication between my laptop and 16F877A mcu. I have used MAX232EPE IC as level converter also. According to my code If I send a character to the MCU, MCU will return a ...
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1answer
40 views

Grounding of a PCB that communicates with a PC via USB or RS232

I have a PCB with an atmega8, communicating with a PC. The signal from TX and RX pins is level-shifted through a MAX232 to standard serial port level, then converted via serial-to-USB commercial ...
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0answers
32 views

Not getting any bytes being read/write from the rs-232 to android cable

first time to do some wiring stuffs, would like to ask if the type of cable setup (in highlight) is valid / possible / working? setup type: ...
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1answer
78 views

How can I troubleshoot stuck/flipped bits in a serial connection?

I'm working on reverse engineering some scrap vaccuum fluorescent displays from Noritake that lived their previous lives inside a payphone. No datasheet exists for it since it's a custom part; ...
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0answers
58 views

Extending RS-232 connection with Fiber Optic cable

I am designing a system which consists of two separate sub-systems that are located a distance from each other (approx. 50 meters, possibly 70 meters). There needs to be a communication link between ...
0
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1answer
64 views

Is it possible to use Microcontroller I/O ports as UART ports

I am using NXP P89LPC954 Microcontroller in my design.It has two UART ports. As it is known that UART are point to point connections between two devices. Hence i can only use two devices to connect to ...
0
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2answers
103 views

USB-232 converters - rts/cts latency problem

I am integrating the USB controller FT230X into a new product. It interfaces directly with the 32 bit Cortex M4 MCU, the STM32F303x The receive buffer on the STM32 is only 2 bytes deep, which I ...
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5answers
2k views

Max Serial Cable Length?

What is the maximum length of serial cable I can use, to connection work properly? Is length of serial cable in connection with baud rate? I am using about 5 meter cable at speed 38400 bauds and RS232 ...
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2answers
168 views

Has anyone built an rs232 to usb converter?

I want to implement serial communication into one of my projects, but I'm hesitant to use a serial cable due them them being exceedingly hard to find nowadays. I found an old converter and took it ...
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1answer
308 views

STM32 RS485 connection

I want to interface stm32f0 with rs422 (half duplex and full duplex). What I'm not getting how to connect RE and DE signals to rs 232. From UART I'll be having RX, TX, VCC and GND pins which i need to ...
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0answers
85 views

RS232 to TTL converter problem

I have a RS232 to TTL Converter which has 4 pins Vcc, Tx, Rx, GND . I am trying to make a serial communication with my PC. I have a AVR development board and I have tested my program by connecting ...
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2answers
265 views

Serial, RS232, Modbus, UART and TCP

I want clearly know this, Serial is protocol right? Then what is the Modbus? Is it under serial. And what are RS232 and RS485? What is UART and serial and UART same? What about TCP? TCP and serial ...
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1answer
50 views

RS232-TX voltage translator

Would like your help to clear my doubt and confusion for this circuit http://nil.rpc1.org/wordpress/?p=31. I don't get a sense that how possible the RS232-pin3 TX signal is converted and transmitted ...
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1answer
140 views

How to transmit data from an analog multiplexer to an RS232 COM port on a PC

I am having trouble understanding how to design a circuit that will transmit multiple analog data signals to a computer through one RS232 COM port. The analog data is a simple voltage reading from ...
2
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1answer
2k views

Max232 giving incorrect values at pins

Background: I'm trying to connect a Compact Logix PLC -> MAX232CPE Maxium chip -> arduino. Currently my PLC does communicate modbus RS232 with a request for data from the arduino. I can see this by ...
0
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3answers
120 views

PIC MCU to PC Serial Communication Problem

I was just trying to send continuous stream of letter 'G' from my PIC MCU (PIC18F452) to my laptop. Here is my assembly code that i am using : ...
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4answers
242 views

What is a 3 wire type cross linked serial cable?

I'm trying to use a controller which uses Serial communication with the PC. The documentation says I need to get a 3 wire type cross link serial cable. Is this a null modem cable? The following ...
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1answer
91 views

How to transfer data between RS-422 and RS-485 ports? [closed]

I'm relatively new to behaviors of serial ports such as RS-232, RS-422, and RS-485. I'm wondering how do you initiate data transmission between a system and a device connected to each other thru one ...
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2answers
191 views

“Unable to open parallel port I/O driver” when trying to connect “RS232 to USB” cable on Linux

I have a JDM programmer for pic micro-controllers, but it came with RS232 port. I have bought a "RS232 to USB" cable with its driver for Windows only and I use Xubuntu 14.04 LTS. I have tried ...
0
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4answers
302 views

Why use MAX232 when using USB-to-Serial cable

I was wondering the need to use MAX232 type ICs when using a USB to RS232 converters. A prolific based converter gives the following output, when transmitting 'a' It seems to me that a simple NOT ...
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1answer
100 views

Questions about an atmega32 serial-bus to RS232 with converter and different logic levels

I have an atmega32 and a FUM DCF-U atomic clock (signal receiver and decoder) of HKW-elektronik. The µ-controller works with 5V and the module on 3.3V. I have to build a converter, because the ...
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1answer
104 views

RS232 ISP programming

I have a saleae digital analyzer and i am using it to listen to on a ISP programmer. (not to steal someone's code, but to build my own programmer). It only has two wires (GND & SDA) The data just ...
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3answers
187 views

How to program an ATMega328 using a Serial Port without using programmers such as USBasp

I am currently learning electronics. I recently bought an ATMega328 and an USBasp programmer to begin my learning. But I couldn't use the USBasp to program my chip. So I researched on other ways to ...
0
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1answer
87 views

Simple Interrupt Handling program?

I'm new to Embedded programming and I'm trying to understand how Interrupt handlers work in different contexts/scenarios. I just want to know how a interrupt handler would work in the following ...
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0answers
49 views

Why are RI and DSR signal combined in TIA-561 (RS-232 over RJ-45)?

EIA/TIA-561 is the standard for transmitting RS-232 signals over an RJ-45 modular jack instead of the more familiar DB9 connector. I'm getting most of my information from here: Zytrax They have this ...
0
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1answer
537 views

Serial Communication with rs232/485 and rj45

I am working a project where I want to connect and control, using Labview, TDK-Lambda Power Supply Process Vacuum Controller Ion Gauge (MODBUS interface) They both have rs232/rs485 capabilities, ...
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0answers
51 views

how to connect light transistor to serial out

I want to be able to communicate between two computers through a laser. On the laser's side, I have a raspberry pi turning it on and off. On the receiving side, I want to somehow connect a ...
6
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5answers
3k views

Why is USB cable maximum length is shorter than in RS232?

Why do we need to buffer USB signal if the cable is longer than 5m? Is that because a signal voltage drop? Is that because it drives currents?
0
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2answers
124 views

Generate TTL-level reset pulse from RS-232 level signal

(My knowledge of analog circuit design is severely limited). I am trying to generate a reset pulse for an AVR microcontroller. The reset is active LOW, and the maximum threshold voltage is 0.9V, with ...
1
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2answers
171 views

Is some protection necessary for a RS232 link between PIC-MAX232-Computer?

I have a circuit with a dsPIC which communicates to a computer using a MAX232 (there ain't any optical isolation). The circuit ground is not bounded to the earth. But the equipment case is earthed. ...
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2answers
360 views

How to protect a MAX232 from PIC programming high voltages?

This question is derived from this Board review thread, I thought it would be preferable to make it a standalone question. I want to be able to reset a PIC remotely using the only communication port ...
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1answer
93 views

Board review: is this PIC16F877 RS232+ICSP board correct/robust?

I want to make my own development board based on a PIC, to make a RS232 bootloader from scratch. It's been a while I haven't used a PIC, and it was on a ready made development board. I've looked ...
0
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3answers
387 views

RS232 non-inverting level shifter

I am starting a project that will end up as an RS232 wireless bridge (XBee radios) and have no idea where to find the chip I am in need of. I'm currently in the testing phase without the radios to ...
0
votes
1answer
57 views

Partial load failure detection circuit

I'm working on the power supply of a temperature controller which sends about 5kW of power maximum (230VAC 50Hz) into 3 sets of 12 heaters (actually, 3kW + 1kW + 1kW). I'm at the stage where I need to ...