<p>Read avoirdupois tty line discipline and all that shit. Start with tty(4) and work from there.</p>
<div class="gmail_quote">On May 8, 2012 4:25 AM, "Diego Iastrubni" <<a href="mailto:elcuco@kde.org">elcuco@kde.org</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi all,<br>
<br>
I have been assigned at work to write a specific protocol between two<br>
machines, which eventually will be over RS232. As part of the development I<br>
decided to write it on linux, and simulate the communication using a named<br>
pipe. In theroy, it should be trivail since the protocol only needs to know<br>
about the FD to read/write to, correct? Wrong.<br>
<br>
I face two problems (maybe one, as both problems seem similar):<br>
<br>
When I try to read from the PC (Ubuntu 12.04, 64bit), the read just aborts<br>
returning "0". If I run the application several times, I somtimes see that the<br>
app can read ONE byte. Sometimes.<br>
<br>
When I write from the PC, and read from the device (Andriod, 2.3.7, Linux<br>
2.6.38.8) the android device reads garbage. I mean, the byte count is wrong,<br>
and the content is usually garbage.<br>
<br>
When I connect microcom (busybox) on Android (actually "microcom /dev/ttyS3 |<br>
hexdump -C") I can see that the bytes sent are mostly arriving, however maybe<br>
times bytes are missing, and sometimes the same bytes are read twice (I sent<br>
"testing 123" and read "testing 12323").<br>
<br>
Some remarks:<br>
<br>
- ttyS* are opened on both sides using "open(file, O_RDWR|O_NOCTTY)"<br>
- speeds are set on both side using "csetispeed(&to, B1900);csetospeed(&to,<br>
B1900);", note that I lowered the speed for the test.<br>
- The Android side has no HW flow control (that might be the trigger).<br>
<br>
What would you recommend me to do?<br>
<br>
- diego<br>
<br>
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</blockquote></div>