From: Brown, S. A C. N. 4. <sco...@na...> - 2007-10-10 22:50:49
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Hi, I have an avionics box that sends constant binary data. When I hooked the avionics box up to HyperTerminal, I can see this data stream. On the gumstix, I want to connect this device to /dev/ttyS0 but I noticed that getty was taking control of this port trying to produce a login prompt. Under /etc/inittab I modified the getty to release control of /dev/ttyS0 and now I have an open bidirectional ttyS0. I proved it by connecting HyperTerminal to /dev/ttyS0 on the gumstix and I could type characters from the HyperTerminal onto the gumstix and visa versa. When I hooked up the avionics box to the gumstix, and ran cat /dev/ttyS0 nothing shows up on my screen. I even tried tail /dev/ttyS0 and still nothing came cross the port. Shouldn't I see junk coming onto the gumstix from the avionics box? Anyone have any suggestions? Thanks, Scott Brown |
From: Mark H. <ma...@th...> - 2007-10-11 01:48:13
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Try cat < /dev/ttyS0 -M. _____ From: gum...@li... [mailto:gum...@li...] On Behalf Of Brown, Scott A CIV NAVAIR, 472500D Sent: Wednesday, October 10, 2007 4:50 PM To: gum...@li... Subject: [Gumstix-users] Open bidirectional ttyS0 Hi, I have an avionics box that sends constant binary data. When I hooked the avionics box up to HyperTerminal, I can see this data stream. On the gumstix, I want to connect this device to /dev/ttyS0 but I noticed that getty was taking control of this port trying to produce a login prompt. Under /etc/inittab I modified the getty to release control of /dev/ttyS0 and now I have an open bidirectional ttyS0. I proved it by connecting HyperTerminal to /dev/ttyS0 on the gumstix and I could type characters from the HyperTerminal onto the gumstix and visa versa. When I hooked up the avionics box to the gumstix, and ran cat /dev/ttyS0 nothing shows up on my screen. I even tried tail /dev/ttyS0 and still nothing came cross the port. Shouldn't I see junk coming onto the gumstix from the avionics box? Anyone have any suggestions? Thanks, Scott Brown |
From: Dave H. <dhy...@gm...> - 2007-10-11 02:31:13
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HI Scott, > I have an avionics box that sends constant binary data. When I hooked the > avionics box up to HyperTerminal, I can see this data stream. On the > gumstix, I want to connect this device to /dev/ttyS0 but I noticed that > getty was taking control of this port trying to produce a login prompt. > Under /etc/inittab I modified the getty to release control of /dev/ttyS0 and > now I have an open bidirectional ttyS0. I proved it by connecting > HyperTerminal to /dev/ttyS0 on the gumstix and I could type characters from > the HyperTerminal onto the gumstix and visa versa. When I hooked up the > avionics box to the gumstix, and ran cat /dev/ttyS0 nothing shows up on my > screen. I even tried tail /dev/ttyS0 and still nothing came cross the port. > Shouldn't I see junk coming onto the gumstix from the avionics box? Anyone > have any suggestions? cat won't setup the baud rate or other serial attributes. I like to use a program I wrote called sertest. It opens the serial in raw mode, and allows bidirectional communication with the serial port (whereas cat is unidirectional). You can find sertest over here: <http://docswiki.gumstix.com/Sample_code/C/Serial> -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: Craig H. <cr...@gu...> - 2007-10-11 06:48:43
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On Oct 10, 2007, at 7:31 PM, Dave Hylands wrote: > HI Scott, > >> I have an avionics box that sends constant binary data. When I >> hooked the >> avionics box up to HyperTerminal, I can see this data stream. On the >> gumstix, I want to connect this device to /dev/ttyS0 but I noticed >> that >> getty was taking control of this port trying to produce a login >> prompt. >> Under /etc/inittab I modified the getty to release control of /dev/ >> ttyS0 and >> now I have an open bidirectional ttyS0. I proved it by connecting >> HyperTerminal to /dev/ttyS0 on the gumstix and I could type >> characters from >> the HyperTerminal onto the gumstix and visa versa. When I hooked >> up the >> avionics box to the gumstix, and ran cat /dev/ttyS0 nothing shows >> up on my >> screen. I even tried tail /dev/ttyS0 and still nothing came cross >> the port. >> Shouldn't I see junk coming onto the gumstix from the avionics >> box? Anyone >> have any suggestions? > > cat won't setup the baud rate or other serial attributes. I like to > use a program I wrote called sertest. It opens the serial in raw > mode, and allows bidirectional communication with the serial port > (whereas cat is unidirectional). > > You can find sertest over here: > <http://docswiki.gumstix.com/Sample_code/C/Serial> I like to use socat for this kind of stuff, because it allows you to specify all the termios stuff on the command line, and lets you do neat tricks like pipe between the serial port and a raw TCP socket, eg: socat open:/dev/ttyS0,raw,clocal,B115200 stdio will connect a binary serial connection to a local device with no flow control at 115200bps to your current stdin/stdout, or socat open:/dev/ttyS0,raw,clocal,B115200 tcp4:somehost:1234 will connect the serial port to a TCP server running on somehost on port 1234, or even socat open:/dev/ttyS0,raw,clocal,B115200 tcp4-listen:1234 will open a TCP server to listen for inbound connections on port 1234 and then will connect those up to the serial port. Or if you enable openssl in socat, you can even use modes like openssl-listen which will automagically encrypt the TCP connection for you. socat is basically like netcat on steroids. C |
From: Scott B. <sco...@na...> - 2007-10-11 17:30:04
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Hi Dave, Dave Hylands <dhylands <at> gmail.com> writes: > > cat won't setup the baud rate or other serial attributes. I like to > use a program I wrote called sertest. It opens the serial in raw > mode, and allows bidirectional communication with the serial port > (whereas cat is unidirectional). > > You can find sertest over here: > <http://docswiki.gumstix.com/Sample_code/C/Serial> I tried sertest and still nothing. I played around with it and I did not see any incoming messages from my avionics box when I ran sertest. #./sertest -d -p ttyS0 -b 57600 I tried different variations with/without -d, -v, /dev/ttyS0, etc... still nothing. So I put the carriage return in the code like the wiki said and reran it to see if that made a difference and I still get nothing. When I typed a character I did see it go out but nothing coming in. Weird... I can see the data stream coming into hyperterminal but nothing coming into the gumstix from the avionics box. I know that getty is disabled from that serial port. I manually disabled it in the /etc/inittab. Thanks for the suggestion, any other ideas? Scott Brown |
From: Dave H. <dhy...@gm...> - 2007-10-11 18:09:04
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Hi Scott, > So I put the carriage return in the code like the wiki said and reran it to see > if that made a difference and I still get nothing. When I typed a character I > did see it go out but nothing coming in. > > Weird... I can see the data stream coming into hyperterminal but nothing > coming into the gumstix from the avionics box. I know that getty is disabled > from that serial port. I manually disabled it in the /etc/inittab. So, are you using a different cable? Perhaps the Tx/Rx isn't connected up properly. Normally, you'd need to use the null-modem cable to talk between a PC and the gumstix, but you'd need to use a straight-thru cable when the gumstix is talking to a device. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: Arlen R. <ar...@gm...> - 2007-10-11 18:21:04
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Scott: Is your avionics box expecting hardware handshaking? It may be looking for CTS (Clear To Send) to be asserted. If the serial connection works with hyperterm and a three wire (RXD TXD GND) serial cable, then this is not the issue. Hope this helps, -Arlen Raasch On 10/11/07, Scott Brown <sco...@na...> wrote: > Hi Dave, > > Dave Hylands <dhylands <at> gmail.com> writes: > > > > cat won't setup the baud rate or other serial attributes. I like to > > use a program I wrote called sertest. It opens the serial in raw > > mode, and allows bidirectional communication with the serial port > > (whereas cat is unidirectional). > > > > You can find sertest over here: > > <http://docswiki.gumstix.com/Sample_code/C/Serial> > > I tried sertest and still nothing. I played around with it and I did not see > any incoming messages from my avionics box when I ran sertest. > > #./sertest -d -p ttyS0 -b 57600 > > I tried different variations with/without -d, -v, /dev/ttyS0, etc... still > nothing. > > So I put the carriage return in the code like the wiki said and reran it to see > if that made a difference and I still get nothing. When I typed a character I > did see it go out but nothing coming in. > > Weird... I can see the data stream coming into hyperterminal but nothing > coming into the gumstix from the avionics box. I know that getty is disabled > from that serial port. I manually disabled it in the /etc/inittab. > > Thanks for the suggestion, any other ideas? > > Scott Brown > > > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |
From: Luke <pu...@fa...> - 2007-10-11 20:37:52
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Hi there, Scott, can you please give a bit more detail about the "avionics box" ? Which brand, model or device is it? Or is it something you've built? Luke Arlen Raasch wrote: > Scott: > > Is your avionics box expecting hardware handshaking? > > It may be looking for CTS (Clear To Send) to be asserted. > > If the serial connection works with hyperterm and a three wire (RXD > TXD GND) serial cable, then this is not the issue. > > Hope this helps, > > -Arlen Raasch > > On 10/11/07, Scott Brown <sco...@na...> wrote: > >> Hi Dave, >> >> Dave Hylands <dhylands <at> gmail.com> writes: >> >>> cat won't setup the baud rate or other serial attributes. I like to >>> use a program I wrote called sertest. It opens the serial in raw >>> mode, and allows bidirectional communication with the serial port >>> (whereas cat is unidirectional). >>> >>> You can find sertest over here: >>> <http://docswiki.gumstix.com/Sample_code/C/Serial> >>> >> I tried sertest and still nothing. I played around with it and I did not see >> any incoming messages from my avionics box when I ran sertest. >> >> #./sertest -d -p ttyS0 -b 57600 >> >> I tried different variations with/without -d, -v, /dev/ttyS0, etc... still >> nothing. >> >> So I put the carriage return in the code like the wiki said and reran it to see >> if that made a difference and I still get nothing. When I typed a character I >> did see it go out but nothing coming in. >> >> Weird... I can see the data stream coming into hyperterminal but nothing >> coming into the gumstix from the avionics box. I know that getty is disabled >> from that serial port. I manually disabled it in the /etc/inittab. >> >> Thanks for the suggestion, any other ideas? >> >> Scott Brown >> >> >> >> >> >> ------------------------------------------------------------------------- >> This SF.net email is sponsored by: Splunk Inc. >> Still grepping through log files to find problems? Stop. >> Now Search log events and configuration files using AJAX and a browser. >> Download your FREE copy of Splunk now >> http://get.splunk.com/ >> _______________________________________________ >> gumstix-users mailing list >> gum...@li... >> https://lists.sourceforge.net/lists/listinfo/gumstix-users >> >> > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > |
From: Scott B. <sco...@na...> - 2007-10-11 17:09:11
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Hi Mark, Mark Hargrove <mark <at> thehargroves.com> writes: > Try > > > cat < /dev/ttyS0 I tried that and still nothing. Thanks for the input thou. Scott |
From: Scott B. <sco...@na...> - 2007-10-11 18:27:12
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Hi Craig, Craig Hughes <craig <at> gumstix.com> writes: > I like to use socat for this kind of stuff, because it allows you to > specify all the termios stuff on the command line, and lets you do > neat tricks like pipe between the serial port and a raw TCP socket, eg: > > socat open:/dev/ttyS0,raw,clocal,B115200 stdio I tried this line and still did not receive any input from ttyS0. > will connect a binary serial connection to a local device with no > flow control at 115200bps to your current stdin/stdout, or > > socat open:/dev/ttyS0,raw,clocal,B115200 tcp4:somehost:1234 > > will connect the serial port to a TCP server running on somehost on > port 1234, or even > > socat open:/dev/ttyS0,raw,clocal,B115200 tcp4-listen:1234 I also tried this line and nothing. > will open a TCP server to listen for inbound connections on port 1234 > and then will connect those up to the serial port. Or if you enable > openssl in socat, you can even use modes like openssl-listen which > will automagically encrypt the TCP connection for you. socat is > basically like netcat on steroids. > > C I walked away from the gumstix for about 5-10 minutes and when I came back in, the gumstix crashed and I couldn't seem to log into it at all from any port. I tried to ssh into it wirelessly, then tried to ssh into it through the usb, and then serially, but a login screen would'nt pop up. It seemed like getty took a dump. After I fiddled with it for about 10 minutes, for some reason, I finally was able to minicom into it but wouldn't let me access the login screen. So now I am reflashing a new filesystem. Thanks for the suggestion. Socat has many options to to play around with but still no visual streaming data from the avionics box on the gumstix. Anyone know what might possibly be going on? Thanks, Scott Brown |
From: Scott B. <sco...@na...> - 2007-10-12 18:18:47
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Hi Dave, Dave Hylands <dhylands <at> gmail.com> writes: > So, are you using a different cable? Perhaps the Tx/Rx isn't connected > up properly. > > Normally, you'd need to use the null-modem cable to talk between a PC > and the gumstix, but you'd need to use a straight-thru cable when the > gumstix is talking to a device. I switched the Tx and Rx lines on the cable and walla, it works. Now I have communications to the avionics box. Thanks a ton for the input. -Scott |
From: Craig H. <cr...@gu...> - 2007-10-12 19:36:58
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On Oct 12, 2007, at 11:10 AM, Scott Brown wrote: > Dave Hylands <dhylands <at> gmail.com> writes: > >> So, are you using a different cable? Perhaps the Tx/Rx isn't >> connected >> up properly. >> >> Normally, you'd need to use the null-modem cable to talk between a PC >> and the gumstix, but you'd need to use a straight-thru cable when the >> gumstix is talking to a device. > > I switched the Tx and Rx lines on the cable and walla, it works. > Now I have > communications to the avionics box. Thanks a ton for the input. Ah, the oldest comms problem in the world: talking while the other person's talking, nobody can hear each other. C |