I am about to write a program to listen and read data from /dev/ttyS0 and write the data to /dev/ttyS1 after processing. Also, the same time I need to listen to /dev/ttyS1 and write to /dev/ttyS0 if any data arrived at /dev/ttyS1.
View 9 RepliesOn my CentOS 5.2 install I've installed a dual-port serial card based on the NetMOS 9835 chipset. I've followed the serial instructions, but everything they tell me to do is already done - see setserial outputs below. I've compared these values to the lspci output (below, NetMos card is at the bottom of the output) for the card and it appears right. Problem being, I can't use the serial ports. Oh and I did use search, and looked at every 9835-related article before posting this :)
[Code]....
I have a bit of a dilemma. I'm attempting to use a microcontroller to send MIDI messages over a virtual serial port. I want to (eventually) read them with Mixxx. I'm using an FTDI chip, so I get a /dev/ttyUSB0. I've tried spikenzielabs' Serial-Midi program, but it doesn't see any serial ports. NOTEMIDI looks really old and won't compile on my 10.04 LTS machine.
View 2 Replies View Relateduser@user-laptop:~$ sudo dd if=sd_backup of=/dev/sdd bs=4M conv=noerror,sync
205520896 bytes (206 MB) copied, 28.564 s, 7.2 MB/s
247463936 bytes (247 MB) copied, 57.1285 s, 4.3 MB/s
260046848 bytes (260 MB) copied, 73.2388 s, 3.6 MB/s
289406976 bytes (289 MB) copied, 104.121 s, 2.8 MB/s
[Code]....
How come dd gets slower after copying this 8GB file? What can I do about it?
I have two usb2serial adapters connected to my PC with a null modem (I am doing some testing to learn serial comm for a particular application). I am writing to /dev/ttyUSB0 a trying to read /dev/ttyUSB1. I have used screen (screen /dev/ttyUSB1 115200) and am able to see the characters being written. I am also able to read and write with Python with the following code
Code: import serial,time,sys
ser1 = serial.Serial('/dev/ttyUSB0',baudrate=115200)
ser2 = serial.Serial('/dev/ttyUSB1',timeout=2,baudrate=115200)
ser1.open()
ser2.open()
[Code]....
I need to talk to several serial ports. I was thinking of having a bunch of USB to serial cables and then plugging all of them into a USB hub, which goes to the computer. What I want to know is, will I see each serial port as a separate thing? With 1 USB to serial cable and no hub, I see /dev/ttyUSB0. With this hub, will I see /dev/ttyUSB0, /dev/ttyUSB1, etc?
View 1 Replies View RelatedI've been able to get access to our Netgear NAS, I can browse it, copy files etc. just fine. But I don't have "direct access" in as far as, Open Office won't open any files residing on the NAS, neither can I save directly to the NAS form a program and when I get a "Browse for File" form field on a website (eg attachments in GMail etc.), I can't browse to the NAS either. My XP box does do all of this, either through my mapped network drive or even through browsing the network. How can I make openSuse 11.2 use the NAS with my login credentials as if it was a local disk?
View 4 Replies View RelatedI've used ext2ifs drivers to mount my ext3 partition in winxp, but I don't have write acces, it's mounted in a read-only mode, and i didn't check the rad-only box during the installation of the drivers. [URL] It's a straithfoward proces so I dont understand what I did wrong. I'm using fresh xp install with (more or less) all the updates and ubuntu 10.04 Also the partition is mounted at /home, so I dont know if that makes any difference.
View 1 Replies View RelatedI've used ext2ifs drivers to mount my ext3 partition in winxp, but I don't have write acces, it's mounted in a read-only mode, and i didn't check the rad-only box during the installation of the drivers.I've used help from the official site http://www.fs-driver.org/and this tutorial http://www.dedoimedo.com/computers/l...s-windows.html
It's a straithfoward proces so I dont understand what I did wrong.I'm using fresh xp install with (more or less) all the updates and ubuntu 10.04Also the partition is mounted at /home, so I dont know if that makes any diferance.
My main workstation incorporates a mixture of ext3, ext4, and NTFS partitions scattered across a number of hard drives. Several of the ext4 partitions are encrypted, and I intend to encrypt the rest of the Linux partitions in the near future.I run VMware workstation, with several Windows OS guests, including Win2K, WinXP and Win7. My Win7 VM is installed on a virtual hard disk, and that virtual hard disk is encrypted using VMware facilities.So this leaves me with a bunch of NTFS partitions that are not encrypted. These are physical partitions on a couple of different hard drives. The reason I have them is ancient and historical, and as I have upgraded my system over time I have maintained the architecture due to the extreme difficulty of rearranging Windows systems.I still need to maintain Win2K and WinXP support, and rearranging those virtual machines would represent a hideous nightmare for me; I really want to maintain the same hard drive partition architecture.But I want to encrypt the NTFS partitions, in a fashion that can be handled by any of the Windows operating systems, AND can be accessed for read and write from Linux.Is this possible? If not using Windows facilities (I don't think ntfs-3g handles encryption, and there are known backdoors in the Windows facilities anyway), is there any third party solution that would work? Would True Crypt do the job in a fashion that would permit access from all the various operating systems, as required? I do generally mount the NTFS partitions in whichever Windows VM is appropriate, then share them out via SMB, but there are circumstances (like when a VM is not running) where I will directly hit them from Linux. So, it is possible for me to contemplate a solution that only works from Windows, but this would cost me the ability to repair/modify those filesystems directly from Linux, which under certain circumstances (a malfunction of the VM, for instance) could be a problem.
View 2 Replies View RelatedReading and writing text files in C?
View 9 Replies View RelatedI would like to write a program that can read every ethernet frame arriving on a specific hardware NIC, without a TCP/IP stack otherwise doing anything on that NIC. Likewise I want to be able to write out to that NIC. So every arriving ethernet frame, of all types, would be readable (probably one at a time to preserve frame boundaries). And every write of exactly that same data would send frames out. The data read and written would be the whole ethernet frame. The kernel would do nothing else with this data, but other NICs would still operate as usual.
What I would be doing is that on 2 separate NICs, copying frames from one to the other, as in bridging. But I would also be doing modifications per what my program needs to do (not at liberty to say what that would be). What facility would I need to be looking at to do this? There is no ethernet device file. Would raw sockets be able to do this? The programming language will be C.
I just want to read and write some values (integer) to my driver. I used put/get user but always getting errors.
driver
Quote:
int Wert;
static int device_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsinged long arg)
int ret;
[code]...
Quote:
int WERT
ret=ioctl(fd, SETIT, WERT)
ret=ioctl(fd, GETIT, WERT)
if i say in C++ WERT is 5 the value arg of the driver becomes 5 but not WERT the returnvalue of get and put user is -1 so it failed.
I want to be able to access my email account from the console. I'm reading all day about fetchmail, postfix, sendmail etc. but all the stuff I found is related to building whole mail system. All I want to do is to read my emails and write some. Which is the painless way to do this? I successfully configured Evolution for this purpose but I want to do that from the console.
View 10 Replies View RelatedI want to write data to serial port ( ttyS ) from inside the kernel.
View 5 Replies View RelatedI have a configuration consisting of:
1. my Atmega168 MCU connected to some servo motors and sensors, and
2. my Linksys WRT54GL router working under OpenWRT Linux WhiteRussian 9.
3. they have a working and tested serial connection.
Now my problem.I open a file descriptor to my serial port called /dev/tts/1, and read a sensor (the second sensor commented, as you see bellow). This works perfect. Then I uncomment the next
sensor, but the code continues to behave as if I didn't uncomment it!If before the reading of the next sensor I first close my original file descriptor and reopen it, it starts to work right, but this is inefficient, as I have various sensors and it is not logical to open
[Code]...
I am trying to read a file character wise and trying to write the same character to another file. In this process, I unable to read and write white spaces successfully to the new file. The script reads the white spaces but while writing the white space is lost. The section of the code, is given below. Please advice how can i read and retain the white space while writing to a new file.
Code:
if [ -s f_test.txt ] && [ -f f_test.txt ]; then
echo "File Exists !!"
while read -n1 char; do
[code]....
At times I see heavy hard-disk activity slowing down system.I have enough RAM and enough of it free.Apparently I am not doing anything that should cause this.'vmstat' shows high numbers for "bi bo" I want to find out which processes are doing "bi bo".How can I zero in on the particular processes?What command?
View 3 Replies View RelatedThere is the Archive::Zip I think I can use with Perl 5.10 but I don't know how. I don't want to read or write any files, just zip something in memory, with best compression, like
$text = "this is a test";
$zippedtext = &Zip($text);
sub Zip {
[code]...
I guess it's only a few lines.
It it safe to read a shared integer while another thread is writing to it on a multicore system?
View 3 Replies View RelatedHere the description of the issue I am having.I am writing a bash test script which reads lines from a file, builds ISO messages, sends them to a server, reads the response with response code and reports the result of the test to a file or on the screen.The message that I need to send is 94 characters long.Here's the portion of a code that I initially wrote:
~ Open socket.
exec 3<>/dev/tcp/172.26.0.25/9991
#~ Send msg.
[code]...
I have got a problem while reading from the serial port. I'm working on iMX-31 board and Eclipse IDE. Whenever I'm trying to read any data through the serial port, it's displaying I/O Possible and the application is being terminated. After reading I'm trying to write this data on a file. Here are the excerpts from the code:
# int main()
{
if (openport()<0)
[code]...
I am setting up my OMAP4 board. I pluged power cable and USB port.But my OMAP4 blaze does not find ttyUSB*. I tried the same OMAP4 on other Linux machine and it is connecting to /dev/ttyUSB2. Do you know any thing I need to configure on my Linux
View 2 Replies View RelatedSamba seems to crash and come back after some seconds if I copy a lot of small files in a short period of time over the network. How do I fix it?
I have Ubuntu 9.10 Server 64bit running on a D945GCLF2 board sharing two 1TB ext4 formatted HDDs to my Windows PCs using samba. I've been having an issue with reading or writing files through samba. It happens during copying operations or checksumming, anything that reads or writes MANY small files in a small amount of time. I am pretty sure the problem has to do with my server because the server has run on two different LANs in different homes and will crash from activity with any of several other PCs. There is no crashing if I access the files through SSH, although when I do that the max transfer speed is less than 1MB/s.
When I induce the crashing, there is absolutely no output to the server terminal.
As an easy access example of something that will crash samba, extracting Cinebench R11.5 to the server will do the job. It always fails.
Whenever I am busy reading or writing large files, or large sum of files, my computer is unresponsive. Screens are getting greyed-out and I just can sit there and wait until the reading/writing is done.
This is not caused by the CPU which is overstressed because it is not. Look at the attachments and you will see the CPU is used for about 20%. When these pictures were captured the computer was using hellanzb to unrar a long list of rar-files.
When you look at my signature you see the computer is not bad at all, just disk-access is slow. I can transfer files with a maximum speed of 30MB/s. Is that normal or is it very slow? I don't know the numbers. I have 2 SATA disks.
O.S. is Mint 9-Isadora, based on Ubuntu 10.04 and I use the 64-bits version.
Am interested in using MT29F2G08AABWP NAND Flash memory for a new embedded design and I couldn�t find a clear specification regarding how reliable is the NAND flash vs. NOR for reading operation.If I program successfully a NAND block, read back and verify successfully the information and never erase or program that particular block again, can I assume that block will remain a good block and the information written there is safe for READING, roughly as safe as a NOR sector?
View 1 Replies View RelatedI am unable to access a serial port as normal user in OS 11.2. The ownership for the port,/dev/ttyS0 belongs to root:dialout. Group dialout has RW permissions.So,I guess the user has to belong to 'dialout' group.Even after a user is included in dialout port,still the user is unable to access,"Permission is Denied".
Before OS 11.2,I used to make the users members of group "uucp" to get serial port access.I tried that also in OS 11.2,without luck.So,I have to be root to access it. This requirement itself seems to be one of the fossils of old time Linux where for normal usage of PC resources,one needed elevated privileges.I guess the trend now is to let the user do all PC work,but in a safe way.
Label on card: "I-440 PCI 4S1P IO Card"
Code:
# lspci -v
...
[code].....
I have a computer with 4 RS232 com-ports (MSI MS-9A19).
To each com-port, I have instruments attached that transmit data like this:
982000001088420<CR><LF>
982000001088421<CR><LF>
[code]....
I have been trying to figure this out for a long time now and can't seem to get it to work. I have three serial ports I need to communicate with. The first one works, but the other two, which have identical product and vendor IDs, do not. This is what I have so far under /etc/udev/rules.d/10-local.rules/
[Code]....