Tagged Questions

0
votes
1answer
88 views

How to reduce a noise on a serial line

I have set up serial communication between my Arduino and a sensor stamp. The sensor stamp in question is Atlas Scientific EC stamp. The communication uses RT232 RS232 serial protocol. The replies ...
1
vote
1answer
53 views

Calculate sum check

I'm trying to send some serial commands. In the manual of the hardware it says: Sum check byte is the summation of all bytes. Higher order bytes are ignored and and the final result is modified. Bit ...
0
votes
2answers
146 views

RS 232 serial sniffing

We have a task in hand to sniff a RS232 protocol in a certain industrial automation setting(we have been asked to do this legally by the manufacturing company itself). We are planning to send a ...
3
votes
2answers
224 views

Serial Port (DB9) signals

Just about every time I use a serial port for anything, I only use 3 pins of the usual 9-pin connector (DB9): Tx, Rx, and GND. And when I wire up my microcontroller projects to these ports, I just ...
0
votes
1answer
214 views

Hardware flow-control (CTS/RTS)

My MCU cannot wake up from UART data, so I wanted it to wake up from the RTS line, but Im having problems understanding the concept. When Im sending data from my MCU to the peripheral, I see the ...
-2
votes
1answer
108 views

Interpret answer of serial connection [closed]

I sniffed some package transfer via COMP1 (RS232) which I can not interpret. As RAW data it looks like: <00><08><44>@<45>@?<F8> ... ...
0
votes
1answer
66 views

PIC24f16KL402 skipping values at serial port

I am trying to write the values of a counter on the serial interface, just to test the interface. The problem is that only every second value (2,4,6,8,...) is received by the desktop. I use port PORTA ...
0
votes
2answers
1k views

Receiving input from RS232 and reading it with Arduino board

Let me begin by stating that I don't have much experience in hardware-related projects. I need to obtain info from a machine that outputs its data from an RS232 cable. http://i.imgur.com/fkqnf.png ...
3
votes
1answer
215 views

What serial signalling format is this? (RS-485?)

This is a mystery signaling standard that I'm trying to sort out. It looks more or less like RS-485 to me, but I don't recognize the long looking start bit, and the "idle" state of the line looks a ...
2
votes
2answers
1k views

Can't figure out EIA-232 (RJ45) to DB9 cable… (seems simple!)

I've purchased a used BayTech RPC4 unit (8-port power strip controllable using RS232). The front of the unit has an RJ45 port (EIA-232) and has a wiring diagram on how to wire it to a DB9 port so you ...
0
votes
0answers
127 views

RJ12 to DB9 RS232 for DELL standby power supply

I'm hoping someone can point me in the right direction. I've got a 1000W DELL SPS (an UPS by another name) and it's got an RJ12 for comms. Under the hood I've found pin 1 goes to ground, 5, 6 goes to ...
0
votes
4answers
290 views

Embedded web server recommendations

I have some sensor hardware that outputs serial data and want to make it into an internet appliance. Essentially, RS232 -to- Wifi, embedded on a web server. Like routers are designed. So that I can ...
0
votes
2answers
403 views

Arduino serial communication with printer

I'm working on a project with an Arduino Mega 2560. I connected the board to a MAX232CPE in order to communicate in serial mode with a thermal printer. I connected the MAX232 to one of the 3 extra ...
3
votes
2answers
153 views

RS-232 and RS-485 software configurability?

I would like to connect a anemometer(RS-485, DB9) to the PC. The PC has a serial port with DB9 connector. I couldn't find the specification of the serial port. Is that RS-232 standard or RS-485? Most ...
2
votes
2answers
156 views

What is the part number for a SIO connector?

What actually is an Atari SIO connector, if I wanted to order the part? I have tried Farnell for DB13, Dsub 13 etc but no joy. I am assembling a SIO2ST for an 800XL.
9
votes
2answers
3k views

What are the differences between USB and RS232?

Can someone tell me why people use either USB or RS232. They are both serial ports, right? And I understand that USB is much faster (especially USB3.0) but if people wanted too I'm sure they could ...
5
votes
3answers
9k views

How can I fix an AVRdude not-in-sync error when programming Arduino via USB-to-serial cable?

I'm trying to build this Ambient lighting for PC. This worked flawlessly on my Arduino Uno. My next step was to make it using "Arduino on a breadboard". So I bought a blank ATmega328 chip and burned ...
1
vote
2answers
239 views

pic18f flooding serial with zeros when reset

I'm connecting a pic18f4520 to the pc via serial (and then use Matlab). I used the max232 level converter and the echo test worked fined. However when I reset the pic it floods the connection with ...
6
votes
2answers
746 views

Why is RS422a more immune to electrical noise than RS232?

I have read that RS-422a cable uses a 20 mA current loop instead of voltage levels. This makes the systems more immune to electrical noise, so the cable can be up to 3000 feet long. I do ...
2
votes
0answers
237 views

Why there is no respond on rs232 port

We are working on communication between AVR and a Crous PTZ. We can see some details about Crous communication ports on page 15 of its guide : We found Crous protocol doc (Got it here) and now we ...
4
votes
0answers
208 views

Serial data transfer from Omega DP80 legacy hardware to computer

Can anyone provide me with some guidance on setting up a legacy serial connection on an Omega (brand) thermocouple display? I would like to use the serial data interface (Omega DP80-Ser) to reliably ...
1
vote
0answers
345 views

Communication between AVR and CORUS PTZ device

12 NULL bytes are being sent to CORUS device (to power on it) with this codevision code like putchar('\0'); Sending is ok , but regarding to page 9 of the ...
2
votes
2answers
456 views

sending data over bluetooth to my hardware through a matlab serial GUI

I have a hardware with RN-41 bluetooth module and the lpc 214 arm microprocessor.Currently my device only sends data to the PC and I am trying to configure it to be able to receive some commands over ...
10
votes
4answers
424 views

Why is RS-422 interface interference insensitive?

I am trying to understand differences between RS-232 & RS-485. I just don't grasp what is the core principle behind RS-422 inteference resistance? Is it number of wires (4 instead of 3)? Is it ...
1
vote
2answers
2k views

PIC18F + MAX232 USART Bizarreness

Okay, I've been struggling with this for weeks, and it's blowing my mind. I have been working with PICs for a long time, and I'm very confused as to why I can't make my USART work. First off, a few ...
1
vote
1answer
152 views

RS-232 Zero (-7V) drops when I connect db9 connectors

I'm interfacing with a system using RS-232. To communicate, I use MAX2322 for TTL <-> RS-232 to interface with PIC microcontroller and PL2303 for USB <-> RS-232 to interface with PC. All of the ...
2
votes
2answers
536 views

Is my SparkFun RS232 Shifter SMD faulty?

Product Link I am connecting this to an Arduino. (once Arduino programmed I removed the USB connector as it shares the serial comms with Pin0&1) RS232<->Arduino VCC <-> 5V GND <-> GND ...
5
votes
4answers
777 views

Trying to figure out available resources on MSP430 LaunchPad

I'm just starting to mess with the MSP430 and have some simple apps working fine. However, now I want to use it with an LCD and am trying to determine if I'm short on I/O. For sure, I'll need to use ...
3
votes
1answer
320 views

Interfacing 16C554 UART to ARM based CPU

Due to deficit of UART's on my board (LPC3141 based) I have the idea to add external multi-channel UART. It has data and address lines, which I'm pretty sure needs to be connected to EBI. ...
2
votes
3answers
4k views

What is the maximum acceptable baud rate error for RS-232 serial communication?

What is the maximum clock difference between a transmitter and receiver for error-free asynchronous serial communication?
2
votes
3answers
439 views

Doubts on Implementing a Simple Protocol for XBee Comms

A system that I'm developing will use XBee modules for a point to point connection between a micro-controller and a PC. Data will only be sent only in one direction -Micro to PC and at 10-20fps. The ...
3
votes
2answers
2k views

Set RS232 port options from MacOS X CLI

Does anybody know the magic command to set baud rate, parity, flow control, etc. for an RS-232 port on the MacOS X CLI?
3
votes
3answers
869 views

Anything special I need to know about RS232 & FT232R?

I'm trying to interface an XSens IMU (http://xsens.com) with my computer, and I'm running into interesting difficulties. The IMU has an RS232 connector that just uses the pins VCC, GND, TX, RX, ...
7
votes
5answers
923 views

RS232-to-USB Converter

Anyone have any recommendations on a good rs232-to-usb converter. There are a lot out there and from the looks of it some are hit or miss. Good driver support is a must.