Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Wrong data with Read from a serial port.
Top Forums Programming Wrong data with Read from a serial port. Post 302732137 by Corona688 on Friday 16th of November 2012 04:40:55 PM
Old 11-16-2012
If there's no newlines, how can you tell when the packet ends? Is it a fixed size? I suspect you're catching packets in the middle, and never finding the end properly.

For that matter, it's not all going to arrive at once, either. Serial data comes in serially if it's a serial port (is it, really? is it actually some USB device?)

Every 50 milliseconds is fast enough to not bother with timeouts, poll(), select(), or anything. Few things are going to be fine-grained enough to handle it, and there's enough buffers to confuse the matter. Just read() will do.
Last edited by Corona688; 11-16-2012 at 06:08 PM..
 

9 More Discussions You Might Find Interesting

1. Linux

Urgent - serial port

Hi All, I am a begineer in Linux, I have 4 ports and 3 are operational port 1,port 2 and port 4 (when I plug in serial device I can see it working) but port 3 seems it is not working. I am sure the hardware is fine. when I give command dmesg | grep tty I get, serial 8250:ttyS0 at... (0 Replies)
Discussion started by: vr_82
0 Replies

2. SCO

data transfer from serial port

dear sir, pls. can you help me ? , my os is unix sco 5.0.4 and ,server dat derive (1,4gb) not working, now i want to transfer my server data in other machine (unix/other possible) by serial port/other port comminication. thanks pankaj raval (2 Replies)
Discussion started by: pankajbraval
2 Replies

3. Programming

Problem with read data from serial device

I have problem with C programming. I want to send & receive data through serial communication. I send data(command) to device to get data from device but when receive data, it can't get altogether of data. It get only some data. What should I do to get altogether of data? If all of... (7 Replies)
Discussion started by: noppon_s
7 Replies

4. Shell Programming and Scripting

Need help with serial port

Hi, I have a external board connected to my serial port. I need to execute "shutdown -r now" command when system boot up. When system boots up it requires a username ans password. Then I need to run my command. I can use rc script but that is rebooting system before it asks for username and... (0 Replies)
Discussion started by: charlie.arya
0 Replies

5. Solaris

How to enable Serial port on ILOM, when Network Port is enabled in parallel

Hi Everyone, In my environment, I have few T5220. On the iLOM Management Card, I have both Network and Serial port are cabled, I don't have any issues while I try to connect using Network Management port, but when I try to connect the serial port for the same server which is actually connected... (3 Replies)
Discussion started by: bobby320
3 Replies

6. Programming

unable to send read and write serial port

hey frns pls help me out !! i hav a code of c that i have to include in my project. i am using a device (geomeda) that has unix based OS. it also support SIM card for connecting to server . I need to send SMS to user from this device.. below code is not working .. i am unable to send sms and the... (7 Replies)
Discussion started by: yashwantkumar
7 Replies

7. Programming

Read from serial port

Hi I try to communicate with a GSM modem, from C, for sending SMS. I use standart AT-commands. Working well with terminal. There is no problem writing ti the port. But when I try to read I only get a echo, I write "ATI" and get "ATI" back, I should get somthing like "SIEMENS 35... (4 Replies)
Discussion started by: dmiller
4 Replies

8. Debian

Reading data from a serial port

Dear List - I am trying to capture data from a serial port and write it to a file. /var/www$ cat /dev/ttyS0 > scale_value.html cat: /dev/ttyS0: Device or resource busy /var/www# cat /proc/tty/driver/serial serinfo:1.0 driver revision: 0: uart:16550A port:000003F8 irq:4 tx:90... (11 Replies)
Discussion started by: Meow613
11 Replies

9. Solaris

Cabling and adapters to communicate to service processor serial port from Windows PC with USB port.

Hello, I have an unloaded T5140 machine and want to access the ILOM for the first time and subsequently the network port after that., and then load Solaris 10 the final January 2011 build. The first part is what confuses me -the cabling. I am coming from a Windows machine (w/appropriate... (5 Replies)
Discussion started by: joboy
5 Replies

LEARN ABOUT OSF1

dc

dc(7)							 Miscellaneous Information Manual						     dc(7)

NAME

       dc - serial line/mouse/keyboard

SYNOPSIS

       controller   dc0   at ibus0   slot 0   vector dcintr

DESCRIPTION

       The  dc	serial	line controller provides DECstation 2100, DECstation 3100, DECstation 5000, and DECstation 5100 computer systems with key-
       board, mouse, and serial communications interfaces. The serial communications interfaces on the DECstation 2100 and DECstation 3100 provide
       partial	modem  control.  The  serial communications interfaces on the DECstation 5000 provide full modem control.  The device special file
       /dev/tty01 on a DECstation 5100 provides full modem control, while the remaining ports provide no modem control at all.	All serial  commu-
       nications interfaces operate at baud rates from B50 to B9600, excluding B200.

       The  dc	ports  are  used as follows: Usage Graphics device keyboard at 4800 BPS Mouse or tablet at 4800 BPS Communications port 1 (w/modem
       control)/local terminal Communications port 2 (w/modem control)/local terminal

       On all systems except the DECstation 5100, serial port 2 is used for the system console port in server (that is,  non-graphics)	configura-
       tions.  On DECstation 5100s, the serial port labeled 3 on the back of the system is always the system console port.  The serial system con-
       sole port always operates at 9600 BPS, 8-bits, no parity; modem control is not supported.

RESTRICTIONS

       Data communications equipment attached to the console serial port in server configurations must be set to 9600 BPS, 8-bits, no parity.  The
       scc driver enforces this restriction.

FILES

       console terminal local terminal local terminal local terminal (DECstation 5100 only)

RELATED INFORMATION

       console(7), devio(7), tty(7), MAKEDEV(8) delim off

																	     dc(7)
All times are GMT -4. The time now is 03:17 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy