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

learn more… | top users | synonyms

-1
votes
2answers
42 views

SIM900 - USB- TTL Communication from PC

I do have some doubts about the communication of the SIM900 GSM module with the PC. By default the GSM module has the RS232 connection to interface with PC. source:link But my PC has only USB ...
0
votes
1answer
25 views

serial data from avr to python

I am using ATtiny2313 microcontroller along with a RS232 to establish communication between my microcontroller and the laptop. Here's my question : What is the predefined system for the laptop to ...
0
votes
3answers
62 views

usb to rs232 to usb

I have a system where there is usb slave device that is in a rotating structure behind a slipring. I need to pass the signal through the slipring (we only have 4 "wires") and onto a computer. Due to ...
-1
votes
3answers
85 views

Is MAX232 is needed?

I'm planning to send data from my laptop via Hyperterminal to Arduino's TX RX pins. Normally RS232 is around +12V -12V; but I will use a USB to RS232 converter as in the figure below: And from a ...
0
votes
0answers
23 views

GSM SIM900A Board and USBtoSerial

just got my SIM900A board same as Connecting GSM SIM900A module with Ardunio and I am trying to connect it to my USB-rs232 converter. I couldn't find any doc on module itself, has anyone done it? Tnx ...
0
votes
1answer
71 views

Programming 16F84A With K8048 software & a custom Hardware (With CH340 USB2Ser)

After reading Manoj's Work about how to program some PICs with USB to Serial Adapter, I decided to try myself to program the 16F84A with my CH340 USB-SERIAL adapter Materials : Software : Cygwin + ...
0
votes
0answers
70 views

RFID card reader : wiegand 26 bits but UID tag 40 bits?

I am working on a project of access control with a Raspberry Pi. I want to buy a RFID card reader (125 khz) and tags. After a lot of research on the web, I found out that the most common connection ...
0
votes
3answers
87 views

Problem connecting two RS232 [closed]

I have a device with a RS232 communication port (3 pin,tx,rx and gnd). When I connect it to a PC RS232, they don't communicate together. I use hyper terminal on the PC side and all setting are ...
1
vote
1answer
208 views

Interfacing barcode scanner with arduino using RS232

I want to connect a barcode scanner with Arduino. I used MAX232 to convert the levels. I have taken only 3 pins: 2(RX), 3(TX) and 5(GND) from the DB9 cable and given them to pins of MAX232 as shown in ...
0
votes
2answers
138 views

Switch a Transistor ON/OFF with Txd Line From USB2SER Adapter (CH340)?[Resolved]

Note/Update: The Problem was The Use of an extension cable (RS232 Null Modem Without Handshaking).So, The RxD & TxD are inverted.it means if you want to measure TxD voltage You should Get it from ...
0
votes
0answers
33 views

when to cascade Modbus TCP/RS-485 gateways?

I've noticed that many Modbus Gateways support cascading. Cascading makes sense, when converting from TCP to RS-232 since RS-232 allows 1 transmitter/receiver on each line. But does it make sense ...
2
votes
3answers
77 views

Why there are data bit lower than 8 data bit of uart

Our group are creating a UART IP Soft Core with Wishbone Wrapper and we are using 5,6,7 and 8 data bit. I just want to know what are the use of the 5, 6 and 7 data bit? In addition to my question ...
0
votes
1answer
38 views

TTL-level camera with MAX3232 installed - is that really TTL-level or an RS232-level?

I've just recycled an LCF-23T CMOS camera (http://www.thaieasyelec.net/index.php/Sensors/Light-/-Imaging/4dsystem-JPEG-Color-Camera-UART-TTL-Interface-OV528-Chip/p_177.html) that the vendor describes ...
1
vote
1answer
114 views

Serial Link Between 3.3V devices

I have an RPi and a freescale FRDM-KL25z controller which will talk over serial protocol. I'm using the pyserial library on the pi: ...
0
votes
0answers
114 views

AVR - Simple(st) serial port programmer

As I'm just getting started with learning anything about microcontrollers, I started from making a very, very simple LPT port programmer (...I think it was just about 4 resistors). It worked well with ...
1
vote
3answers
109 views

Simple RS232 to 8 bit Parallel circuit

I want to make a simple rs232 to parallel (8 bit) converter. I would like the input to 1 wire and the output can just be 8 bit with no strobes etc. and run at high speeds (ideally up to 1Mbps, put ...
0
votes
1answer
83 views

Wiring RS485/422 to RS232 converter to a given device pins [closed]

I'm trying to establish a full-duplex and then a half duplex communication and need to wire a device output to an RS485/422 to RS232 converter. Here is the device output pins for full and half ...
0
votes
1answer
58 views

Accessing RS232 Rx Tx instead of OTG on stellaris LM4F232H5QD evaluation board

I am asking two related questions here: I can see a program uart_echo for stellaris lm4f232h5qd . What I want is that I need to access this data on teraterminal using PA1 and PA2 pins instead of ...
1
vote
1answer
76 views

VHDL RS-232 Receiver

I have been trying to design an RS-232 receiver taking an FSM approach. I will admit that I do not have a very well-rounded understanding of VHDL, so I have been working on the code on the fly and ...
1
vote
1answer
85 views

Pin assignment on rj45 when using rs232

I am having a problem creating a cable to connect with two devices. The first devisce is an Intellivue MP70 that I want to connect to the RS232 port using an RJ45 end. On the other side there should ...
1
vote
2answers
3k views

Connecting GSM SIM900A module with Ardunio

I have bought an SIM900A Mini V4 GSM module. Here is the module, I want to configure with arduino to send and receive SMS. Do I have to connect TXD of this module--Tx of Arduino & RXD of this ...
1
vote
1answer
196 views

RS232 Splitter Capable of Transmitting/Receiving data to one device and only Transmitting to another

I was wondering if it is possible to have a RS232 splitter that is able to split the data into two RS232 connections, and allow for one of the connects to still be able to transmit data back through ...
0
votes
0answers
67 views

Can a USB 5v 0.5A powered pcb sent data to a 3,5 mm jack using a 2nd usb port via usb-to-3,5mm converter wire?

I am designing a MCU for a device that is powered by USB. This device needs to send simple serial commands to an 3.5mm stereo port on a monitor. The wanted to use USB-to-3.5mm jack converter wire, ...
1
vote
2answers
357 views

How can RS-232 DTR / RTS pins be used for power?

I want to interface to this device where (sec 4.2) states can be powered from the DTR and RTS handshaking lines by having one high and one low Also, Wikipedia states: No method is ...
0
votes
2answers
115 views

Arduino: RS232 Level Shifter or RS2323 Breakout needed?

I am trying to establish communications between an Arduino Mega2560 (Master) and a customised controller (Slave) via a Master-Slave RS232 link using Modbus RTU. The communication should be ...
0
votes
0answers
71 views

RS485 half duplex communication issue

I have a London MR400s taximeter and I wanted to communicate with it so I have connected it with my PC using RS485 half duplex cable. I am using termite terminal for polling and receiving the data. ...
0
votes
1answer
90 views

Current loop Converter

Is it possible to convert a 2 wires current loop to RS232, and from RS232 to current loop, I am trying to put an RS232 sniffer in the middle so I can see what they are communicating to each other. I ...
0
votes
1answer
184 views

Connection problem with RS485 system on PC with RS232 port

I am developing a system in which I have to integrate hardware. I am from computer background, so I don't have much knowledge about hardware systems. The issue is I have to integrate with London ...
1
vote
1answer
182 views

VHDL USB UART Problem

I've just described an UART transmitter and receiver in VHDL. In simulation everything seems to be fine. In FPGA, the loopback interface works well: I push a button, the transmitter sends data, the ...
0
votes
1answer
217 views

Digital Multimeter to RS232 Serial Port or USB - DT830D

I am new to Electronics and doing a hobby project. I want to take some readings and get them on the computer/laptop. I am ok with both RS232 (Serial) or USB (preferred). I have a DT830D Multimeter. I ...
7
votes
2answers
895 views

How does the MAX232 double the voltage?

MAX232 Datasheet Hi, I am currently a student so bear with me please! I'm currently using a powering the MAX232 with 5V DC, and when I measure from VCC to lets say, pin 3, I am getting a voltage ...
0
votes
1answer
567 views

What are all of the pins of the Beaglebone Black Rev. C serial (debug) header?

The Beaglebone Black Rev. C has a serial debug header with 6 pins. I would like to know what each of these pins is. If numbered 1-6 starting closer to the 5v barrel connector, pin 1 is ground, pin 4 ...
0
votes
0answers
119 views

Finding out RS232 commands from massage chair

Hey all I have a very quick question to ask about the Bus Pirate before I go ahead and order or not order it. I am looking to get the RS232 commands from a massage chair. It has an ugly, bulky "box" ...
1
vote
0answers
85 views

Remote control of audio equipment over RS-232 with Arduino

These questions are following on from my previous question Reverse engineering old serial devices and cloning with Arduino about the monitoring of RS-232 traffic. I had some good success and now have ...
3
votes
1answer
234 views

How to setup a RS-232 Cape for BeagleBone Black

I'm trying to use a RS-232 cape in a python script. A TU-S9 USB-to-Serial converter works just fine with same code I just change the port. So I don't think it is my code. The only thing I can think of ...
3
votes
2answers
214 views

Reverse engineering old serial devices and cloning with Arduino

I have a piece of music equipment that uses a remote control. This remote control communicates bi-directionally with the main unit. It communicates over RS-422 protocol (mainly for the cable distance, ...
0
votes
2answers
126 views

Convert FTDI USB signal back to serial

I have a data logger with a USB output (FTDI FT232RL) and I'm trying to get the information remotely using a XBee modem, but my problem is that I need to "convert" the USB signal back to serial to ...
1
vote
1answer
171 views

No correct signal from ATMEGA162 UART

I got the following circuit: simulate this circuit – Schematic created using CircuitLab And this code to run it: ...
0
votes
2answers
95 views

If RS-232 defines electrical characteristics, what is the transfer protocol?

From this answer, it says RS-232 defines the voltage levels and what not of a signal. I want to be able to read barcodes on my microcontroller with something like this. The closest datasheet I ...
4
votes
2answers
371 views

Opto-coupled RS-232 receive circuit

I am looking into a implementing a low-cost RS-232/422 opto-coupled receive circuit. The aim is surge protection and tolerance to DC offsets. The challenge is that the inputs should be completely ...
0
votes
2answers
176 views

Does BAFO “BF-810 USB to Serial Adapter (DB9)” supports full serial port?

Does BAFO BF-810 USB to Serial Adapter (DB9) support full serial port (hardware flow control) functionality? If not, how can I test full serial port functionality using serial port only with TX, RX?
0
votes
2answers
144 views

Pictures of different adapters, trying to understand how they work (PLC to PC communication)

I purchased the blue adapter in the picture as a USB/RS232 converter. It takes in the RJ12 cable from my PLC, and converts it to a USB input. Now when I try to use an RJ12-DB9 Female and then connect ...
0
votes
1answer
160 views

Is an USB-to-UART converter different from an USB-to-RS232 converter? [duplicate]

I have a USB-to-RS232 converter. The GND, TX and Rx pins of the RS232 I connect to GND, Rx and Tx on a development board I have. I've set the right baud rate, flow control and other settings in my ...
0
votes
2answers
483 views

MAX3232 overheating/burnt after connecting to PC

I've got a MAX3232 Serial-to-TTL RS232 board which I am currently using in factory assembly lines. I don't have its picture, but here's a similar product: This is the circuit I've managed to figure ...
5
votes
5answers
2k views

Why are there so many resistors in a typical schematic?

I know that some resistors cause pull-up or pull-down or work as a voltage divider and/or current divider. But sometimes I cannot understand their function in some simple circuits: Take this motor ...
1
vote
2answers
97 views

Simple FPGA serial communication not working

FPGA board (manual) USB-to-RS232 cable (controller) synthesis reports I created a simple schematic which shorts the TXD and RXD pins according to the manual. However, when I use RealTerm to send ...
0
votes
0answers
383 views

Send AT commands to UART device, what am I missing?

It all started with me wanting to change the pairing code of a bluetooth device, and now I'm knee-deep in electronics... I have a miniELM327 bluetooth interface with PIN "1234" , I want to change it. ...
3
votes
2answers
1k views

Can I split one RS232 output signal into two signals? [duplicate]

I have one controller which processes data from a weigh scale. With it I can capture data using hyper terminal on a PC (RS232 communication - standard DB9 connector). Now I want to analyze it on ...
-1
votes
3answers
125 views

MCU cannot communicate with Bluegiga WT12 module

I have the evaluation kit EK-WT12 for Bluegiga WT12 module being controlled by a TI Launchpad. I have used the evaluation kit to communicate to a computer with SPP profile and I have sent and received ...
0
votes
0answers
120 views

USB CDC RS-232 interface to Bluetooth or WiFi

I have a device that communicates with a computer via an USB CDC RS-232 interface. The thing is that I want to build an interface (on top of that USB interface) that enables the device to ...