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

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386 views

What are free RS-232 terminal programs? [migrated]

I've read signals from an AVR in university, but I forgot what software I was using. I can't seem to find any on google. Maybe I am not looking right. What are some free UART software for AVRs? I ...
0
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2answers
60 views

Do you really need all of the sigals for a general RS-232 port?

I know that having TX, RX, GND, RTS, CTS are good. What about all of the others? Do devices these days even make use of the other pins (DSR, RI, DCD, DTR)? Is it safe to generally leave out these ...
2
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0answers
47 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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2answers
113 views

Speed problems in homemade RS232-to-TTL converter board

I'm still trying to debug this RS232-to-TTL converter board that I've made, shown below. Now I think I've narrowed down the problem to speed: it works fine at 57,600 baud; but it inserts some ...
2
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1answer
26 views

Is it possible to use the RTS pin as DTR?

I'm deveoloping a project with a raspberry Pi that involves serial communication. In order to properly handle voltage levels, I used a max3232 converter between the raspberry and the external device ...
5
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2answers
217 views

Problems with homemade RS232-to-TTL converter board based on TI's MAX232

I've designed an RS232-to-TTL converter board based on TI's MAX232 IC that I plan to use to program a few custom Arduino boards that I have. However, I'm having trouble with the board and I'm hoping ...
0
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0answers
41 views

Why can't I use my AVR programmer with serial functions?

I recently created a project in which I made my own AVR test bed based on the Arduino Uno. I used the ATmega 328P and I have set up all the fuses for the external clock and the Arduino IDE to ...
0
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2answers
94 views

3.7v > 3.3v voltage stepdown with logic-driven on/off control [paused]

(PAUSED): This topic is currently on hold as I source necessary hardware. I need to connect a Wi-Fi/RS232 module to a low-powered monitoring device, and for maximum portability, I'd like to power the ...
1
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1answer
73 views

Voltage level too low for MAX232

I'm trying to connect TI's MAX232 to my Arduino so that I can communicate with my PC. I have connected it exactly as the picture shows: Tx/Rx are not connected because I just wanted to see if I can ...
3
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3answers
322 views

Can I screw up my board by guessing which RS232 pins are which?

I have a Raspberry Pi that I want to hook up to a serial (RS232) cable. I've found and read some information about this, so I know what pins on my RPi are Rx/Tx/3.3V/Gnd... Now the cable I'm hooking ...
0
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1answer
57 views

Connecting 4 devices on RS232

I have two PCs (very old, without usb but rs232 port) that talks via RS232. They send to each other very small bit of info ( one character every 10sec). Now I need to connect additionally two sensors ...
1
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0answers
62 views

RS232 Grounding question

I want to connect 2 devices together using RS232. I initially thought both devices used the power ground as the reference signal for their RS232 (they're powered by the same PSU) so I designed my ...
2
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3answers
142 views

When do we use all pins in RS-232 cable?

I think the minimum for simplex communication are TX so we can transmit and the power supply pins +Vcc and GND. That is all we need. When do we need to use all 9 pins of RS-232? I think that the ...
1
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2answers
148 views

How would I make an Arduino Due recieve RS-232/422 signals?

Background on this question is here: Oops, I accidentally need to build an embedded system. What would that look like? I'm looking at purchasing an Arduino Due to take in 3 (well, ultimately 5, but ...
7
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3answers
319 views

What can I do to decrease the latency from these serial ports which are attached to a PC via a Serial to USB adapter?

I think I have accidentally discovered a need in my life for embedded systems. Which is great! And kind of scary. And I need help. Background: I got hired to build a GUI application which takes scans ...
0
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0answers
56 views

FT2232H as USB to MCU UART configuration using D2XX

I'm having trouble using the FT2232H as a USB to MCU UART bridge. I was able to open the device using and set the baud rate using D2XX commands. However, I cant see any UART output in my logic ...
0
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2answers
160 views

Connect Arduino to RS232

I have a device that is powered by the Arduino (+5V). The device (a VC0706 Powered camera), incomporates a MAX3232 to convert to RS-232. Unfortunatly, I don't have the tools or dexterity to remove ...
1
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1answer
88 views

Honeywell Dead Reckoning Module GPS Problems

This was previously posted in the Stack Exchange forum and I was referred here. I'm currently trying to connect a Honeywell DRM4000L to a GPS module. The DRM is a dead-reckoning device which takes a ...
0
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2answers
123 views

Getting started with an LPC1313 Microcontroller [closed]

I recently purchased this microcontroller along with an FTDI TTL-232R-3V3 cable. I want to program a blinking lights hello world application onto the microcontroller. I was told that I might be able ...
4
votes
2answers
164 views

Is “RS-232 Cable” a valid term?

As "RS-232" is a Protocol/Standard, "DB-9" is a type of Connector, Is RS-232 Cable a valid term? Or is there any proper name for that? "Serial Cable" maybe!
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4answers
99 views

How is it that this transistor drives the line such that we get a RESET event?

I am a bit confused on how this schematic works. It looks as if when we do not have any data coming in (i.e. 0V constant) from pin 3 on the DB-9 then the transistor will be off and the RESET will be ...
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2answers
163 views

Holding register in microcontroller for Modbus RTU

I'm very noob in microcntroller modbus. I want to do Modbus RTU slave device using RS232. I read modbus documentation from modbus.org site. But still I'm not clear about few things. How to define the ...
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3answers
413 views

RxD TxD equivalent pins in USB

I want to build a USB Programmer currently for AT89C51. I am stuck on how to make it communicate with PC. In RS232, the RxD TxD pins are straight forward, we just need to use Logic Level Converter to ...
2
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3answers
80 views

How to write to block memory?

I need to write 16x16 bit data to block memory. I am using RS232 to send data. To get 16 bit data, I send 2x8bit. Now, how can I write my data to the memory? I have a write signal and 16 bit input ...
0
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0answers
176 views

Can I get by with Max232 clone programming Arduino Mini Pro?

Do I need USB->RS232 converter (FTDI or the likes) to program Arduino Mini Pro with a PC, or can I use just a RS232C->RS232 converter (MAX232 clones)? I happen to have the latter, but would need to ...
0
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1answer
95 views

Looking for a serial 9800 baud device that can input a string and output a modified string

I'm looking for a simple programmable device that has RS232 inputs and outputs that can take a string of ten numbers and output a modified string over 9800 9600 baud, 8 bits, 1 stop bit, parity: ...
0
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1answer
110 views

RS232 and realterm communication problem

I am not seeing anything on a port in realterm though it is properly sending the data through the port. Anyone run into a similar situation? What am I doing wrong? I am using a C8051F120 developers ...
0
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1answer
104 views

Serial Port Terminal transmitting at 300 baudrate

I have been using Hercules SerialPort Terminal for a while now and its pretty cool. But now, I need to send data's at 300Baud, but Hercules stops at 9600baud. I find TeraTerm which looks okay as ...
3
votes
7answers
351 views

Best PC interface for simple custom hardware

What interface of your PC do you use in order to connect to simple custom hardware? The most commonly used interface was RS232 some while ago and today is probably USB, but wouldn't it be simpler for ...
2
votes
1answer
102 views

Easiest way to detect a button push

I have a button that when push turns on a little light (light blinks; like a counter) - is there an easy way to hijack this signal so that my windows box can also detect if the button is pushed? I ...
1
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4answers
471 views

USB to Serial Converter using the CDC/ACM specification

I try to use a Usb to Serial converter in a windows store application. As the windows store application does not Support SerialPorts i need to find a USB/Serial Converter that supports CDC/ACM. Here ...
0
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1answer
164 views

RS232 and RS422 (Isolated and ESD Protected)

I want my RS232 and RS422 to be galvanically isolated and ESD protected. I have two options to implement this requirement. Option 1: MCU-->OPTO-->DRIVER-->ESD PROTECTION Use MAX3232 for RS232 ...
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0answers
66 views

TI MAX3237 TTL / RS232 transciever, transmission not working

I've got a TI MAX3237 5 TX / 3 RX transceiver (TI datasheet, Maxim datasheet) set up as follows: The supply is 3V3 from a BeagleBone Black, measured at 3.35v. The CMOS level inputs and outputs ...
0
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0answers
142 views

design suggestion for serial to ethernet bidirectional connection

I am working on a project.My requirement is to enable communication between one serial interface(DB9-RS232) with an Ethernet interface(RJ45), via a microcontroller. after searching a lot, the most ...
0
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1answer
85 views

What is the difference between SBC & Development board?

I was searching for an dev board with RS 232 interface and with capability to implement ethernet interface as well(either on same board or using accessory board) then I came across Single Board ...
0
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2answers
135 views

MAX232 chip by TI not functioning correctly?

I'm trying to use this to convert rs232 levels from my gsm modem to 5v TTL. I was struggling to get it working. So I devised a test to see if I even got any form of communications. My custom Arduino ...
-2
votes
1answer
70 views

LCD that can be controlled via serial? [closed]

I am very new to hobby electronics, but I was hoping I could find a way to get an LCD (preferably a backlit monochrome LCD with a grid of pixels -- something like this) that I could somehow mount in ...
4
votes
4answers
1k views

Do I need MAX232 when using USB-to-Serial cable?

I am willing to build an AVR JTAG debugger (I grabbed from here: http://aquaticus.info/jtag) but the circuit uses COM port and it has MAX232 transceiver. My Laptop does not have COM port, so I need a ...
0
votes
3answers
154 views

Can i send a reset signal through the serial port?

I want to send a signal through the serial port to restart a modem, enfora gsm1218 (see datasheet http://www.testech-elect.com/enfora/pdf/GSM1218HR.pdf) is it possible? I know that an AT command ...
1
vote
1answer
57 views

Is possible use driver and receiver from different RS232 IC?

I need RS232 IC with Features: power supply 3.3v, ESD protection, 8-drivers/8-receivers. I'm looking for ic with these specifications are not found. These needs can be met if I use two IC is ...
1
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2answers
98 views

usb daq device to rs232

We have a piece of data acquisition equipment (voltage data logger) that connects to a PC via a USB cable for power and communication. Because of some other equipment we already own, it would be ...
0
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2answers
123 views

RS232 hotplugging

I've noticed that when I connect/disconnect the RS232 cable to my micro-controller, I receive a garbage character at the other end (my pc). Is there a way to prevent this? I want to eventually move ...
1
vote
2answers
160 views

Where to connect DB9 Ground Pin on a Serial RS232 connection?

I want to connect my DIY basic stamp via RS232 MAX232 to the serial port on my laptop. Now since I'm a complete newbie in electronics, what do I do with Ground Pin 5 on the DB9? I assume ground means ...
-2
votes
2answers
454 views

3.3 v TLL to RS232 (To Connect Pic with PC)?

Is there any ic like MAX232 that can level shift 3.3v TLL to RS232? I need it to debug a pic running on 3.3 V with my pc.
3
votes
2answers
189 views

How to remove Noise/Voltage in TX pin of PIC16F877?

I wanna connect an existing device to PC using RS485/RS232. I have programmed the microcontroller correctly and it works when I haven't switch on the power of device. I mean after programming by PIC ...
18
votes
2answers
1k views

What is the meaning of “half bit” in this context?

In RS-232 specification, the stop bits can be 1, 1.5 or 2 stop bits...I wonder how it's possible to have half a bit? Also some ADC math uses 0.5bit precision in the IC specifications/datasheet. Can ...
0
votes
1answer
77 views

ADUC7024 UART not working

I am currently working on getting my ADUC7024 (ARM7) microprocessor to communicate with me via UART/RS232. I have tried everything and I'm getting really desperate especially since the provided ...
0
votes
1answer
134 views

read from serial buffer

I am trying to interface a dsPIC33EP chip with a RS232 device at baudrate=460800. My code works OK but I think there must be a better way to do this. Here is the code: ...
0
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0answers
298 views

RS232 Ground-Loop Isolation: “creative” solution?

I have a RS232 connection that seem to suffer from different ground potentials at the two ends of the connection: The receiver signals a "break condition" in Realterm. As I understand it this means ...
1
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0answers
261 views

Control Arduino Bluetooth RS232 module with java [closed]

I'm Ubuntu user and I have connected RS232 wireless bluetooth module with arduino and I still be able to control the LED with ubuntu terminal using ...