Path: csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!news.glorb.com!news-out.readnews.com!transit3.readnews.com!panix!not-for-mail From: Grant Edwards Newsgroups: comp.os.linux.development.apps Subject: Re: termios Date: Sun, 26 Jun 2011 02:27:07 +0000 (UTC) Organization: PANIX Public Access Internet and UNIX, NYC Lines: 34 Message-ID: References: <4dfb6e98$0$30769$ba4acef3@reader.news.orange.fr> <4dfcc0dd$0$14684$ba4acef3@reader.news.orange.fr> <4dfce742$0$30775$ba4acef3@reader.news.orange.fr> <4e04c885$0$30751$ba4acef3@reader.news.orange.fr> NNTP-Posting-Host: 67-220-17-92.usiwireless.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: reader1.panix.com 1309055227 19059 67.220.17.92 (26 Jun 2011 02:27:07 GMT) X-Complaints-To: abuse@panix.com NNTP-Posting-Date: Sun, 26 Jun 2011 02:27:07 +0000 (UTC) User-Agent: slrn/0.9.9p1 (Linux) Xref: x330-a1.tempe.blueboxinc.net comp.os.linux.development.apps:163 On 2011-06-24, Tauno Voipio wrote: > On 24.6.11 8:28 , michel simian wrote: >> Tauno Voipio ??crivit de sa plume: >> >>> Attached is a module running RS-485 packet traffic under >>> Linux on an Atmel AT91RM920 serial port with hardware control >>> of transmit enable. >> >> So, it was a bit difficult to adapt, -I'm speaking about your sample >> - but I realize that my kernel was a little bit too old (2.6.26). >> Some of serial.h defintion was'nt there. I tried it on a 2.6.32, and >> I had to find the include files containing some define of ioctl... >> Then finally, I install a 2.6.35 and I could read the device's >> answer. But I could not find how to disable the automatic echoing. >> modifying the CREAD termios bit will block the write. modifying the >> ECHO termios bit doesn't have any effect. >> >> I have to try and to search more. :) > > The echo is in hardware - learn about RS-485. What he said. :) > The transmit and receive use the same wires, so everything sent to > the bus ends up t the own receiver, too. Sometimes there's a jumper that controls the read-back of tx data. If not, you're going to have to write your software so that it ignores the echoed data. -- Grant