ttyUSB writing the received data back
I have CP2108 device connected to my hardware, it has 4 interfaces: /dev/ttyUSB0, /dev/ttyUSB1, /dev/ttyUSB2, /dev/ttyUSB3
I connected /dev/ttyUSB0 to /dev/ttyUSB1
We have also set the baud rate properly to 9600 using stty command
I am transmitting hello from echo "hello" > /dev/ttyUSB0
I receive "hello" back in /dev/ttyUSB1 and /dev/ttyUSB0
cat /dev/ttyUSB0
cat /dev/ttyUSB1
Looking at the driver logs, after read_callback on USB1 it also calls write_callback , why is this happening, as the expected behavior is to only receive on USB1
Thanks for your patience and time
Update:
stty -a -F /dev/ttyUSB1
speed 600 baud;stty: /dev/ttyUSB1
line = 216;
intr = f; quit = ^B; erase = M-'; kill = 8; eof = <undef>; eol = <undef>; eol2 = <undef>; swtch = ^?; start = s;
stop = @; susp = <undef>; rprnt = <undef>; werase = <undef>; lnext = ^C; flush = <undef>; min = 0; time = 0;
-parenb parodd cs5 -hupcl -cstopb cread -clocal crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip inlcr -igncr icrnl -ixon -ixoff iuclc -ixany imaxbel -iutf8
-opost olcuc ocrnl onlcr onocr onlret ofill ofdel nl1 cr3 tab3 bs1 vt1 ff0
-isig icanon -iexten echo echoe echok echonl noflsh xcase tostop echoprt echoctl echoke
c serial-port linux-device-driver tty
asked Nov 13 '18 at 6:34
md.jamalmd.jamal
424519
add a comment |
I have CP2108 device connected to my hardware, it has 4 interfaces: /dev/ttyUSB0, /dev/ttyUSB1, /dev/ttyUSB2, /dev/ttyUSB3
I connected /dev/ttyUSB0 to /dev/ttyUSB1
We have also set the baud rate properly to 9600 using stty command
I am transmitting hello from echo "hello" > /dev/ttyUSB0
I receive "hello" back in /dev/ttyUSB1 and /dev/ttyUSB0
cat /dev/ttyUSB0
cat /dev/ttyUSB1
Looking at the driver logs, after read_callback on USB1 it also calls write_callback , why is this happening, as the expected behavior is to only receive on USB1
Thanks for your patience and time
Update:
stty -a -F /dev/ttyUSB1
speed 600 baud;stty: /dev/ttyUSB1
line = 216;
intr = f; quit = ^B; erase = M-'; kill = 8; eof = <undef>; eol = <undef>; eol2 = <undef>; swtch = ^?; start = s;
stop = @; susp = <undef>; rprnt = <undef>; werase = <undef>; lnext = ^C; flush = <undef>; min = 0; time = 0;
-parenb parodd cs5 -hupcl -cstopb cread -clocal crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip inlcr -igncr icrnl -ixon -ixoff iuclc -ixany imaxbel -iutf8
-opost olcuc ocrnl onlcr onocr onlret ofill ofdel nl1 cr3 tab3 bs1 vt1 ff0
-isig icanon -iexten echo echoe echok echonl noflsh xcase tostop echoprt echoctl echoke
c serial-port linux-device-driver tty
asked Nov 13 '18 at 6:34
md.jamalmd.jamal
424519
1
You need to analyze the termios settings of the receiving serial terminal, i.e.stty -a -F /dev/ttyUSB1, to see if echoing is enabled. It probably is, since it's commonly employed for normal canonical terminal communications.
– sawdust
Nov 13 '18 at 8:14
Vote to close: this isn't a programming question.
– sawdust
Nov 13 '18 at 8:16
I added stty command output. Can you please look
– md.jamal
Nov 13 '18 at 8:24
3
its because you have echo enable. trystty -echo /dev/ttyUSB1this will solve echo issue. credit goes to sawdust who asked for these stty logs. hope this solves the issue.
– Devidas
Nov 13 '18 at 9:20
After disabling all the -echo it solved the problem. Thanks sawdust, Devidas
– md.jamal
Nov 14 '18 at 6:52
add a comment |
I have CP2108 device connected to my hardware, it has 4 interfaces: /dev/ttyUSB0, /dev/ttyUSB1, /dev/ttyUSB2, /dev/ttyUSB3
I connected /dev/ttyUSB0 to /dev/ttyUSB1
We have also set the baud rate properly to 9600 using stty command
I am transmitting hello from echo "hello" > /dev/ttyUSB0
I receive "hello" back in /dev/ttyUSB1 and /dev/ttyUSB0
cat /dev/ttyUSB0
cat /dev/ttyUSB1
Looking at the driver logs, after read_callback on USB1 it also calls write_callback , why is this happening, as the expected behavior is to only receive on USB1
Thanks for your patience and time
Update:
stty -a -F /dev/ttyUSB1
speed 600 baud;stty: /dev/ttyUSB1
line = 216;
intr = f; quit = ^B; erase = M-'; kill = 8; eof = <undef>; eol = <undef>; eol2 = <undef>; swtch = ^?; start = s;
stop = @; susp = <undef>; rprnt = <undef>; werase = <undef>; lnext = ^C; flush = <undef>; min = 0; time = 0;
-parenb parodd cs5 -hupcl -cstopb cread -clocal crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip inlcr -igncr icrnl -ixon -ixoff iuclc -ixany imaxbel -iutf8
-opost olcuc ocrnl onlcr onocr onlret ofill ofdel nl1 cr3 tab3 bs1 vt1 ff0
-isig icanon -iexten echo echoe echok echonl noflsh xcase tostop echoprt echoctl echoke
c serial-port linux-device-driver tty
asked Nov 13 '18 at 6:34
md.jamalmd.jamal
424519
I have CP2108 device connected to my hardware, it has 4 interfaces: /dev/ttyUSB0, /dev/ttyUSB1, /dev/ttyUSB2, /dev/ttyUSB3
I connected /dev/ttyUSB0 to /dev/ttyUSB1
We have also set the baud rate properly to 9600 using stty command
I am transmitting hello from echo "hello" > /dev/ttyUSB0
I receive "hello" back in /dev/ttyUSB1 and /dev/ttyUSB0
cat /dev/ttyUSB0
cat /dev/ttyUSB1
Looking at the driver logs, after read_callback on USB1 it also calls write_callback , why is this happening, as the expected behavior is to only receive on USB1
Thanks for your patience and time
Update:
stty -a -F /dev/ttyUSB1
speed 600 baud;stty: /dev/ttyUSB1
line = 216;
intr = f; quit = ^B; erase = M-'; kill = 8; eof = <undef>; eol = <undef>; eol2 = <undef>; swtch = ^?; start = s;
stop = @; susp = <undef>; rprnt = <undef>; werase = <undef>; lnext = ^C; flush = <undef>; min = 0; time = 0;
-parenb parodd cs5 -hupcl -cstopb cread -clocal crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip inlcr -igncr icrnl -ixon -ixoff iuclc -ixany imaxbel -iutf8
-opost olcuc ocrnl onlcr onocr onlret ofill ofdel nl1 cr3 tab3 bs1 vt1 ff0
-isig icanon -iexten echo echoe echok echonl noflsh xcase tostop echoprt echoctl echoke
c serial-port linux-device-driver tty
c serial-port linux-device-driver tty
asked Nov 13 '18 at 6:34
md.jamalmd.jamal
424519
asked Nov 13 '18 at 6:34
md.jamalmd.jamal
424519
edited Nov 13 '18 at 8:24
md.jamal
asked Nov 13 '18 at 6:34
md.jamalmd.jamal
424519
asked Nov 13 '18 at 6:34
md.jamalmd.jamal
424519
asked Nov 13 '18 at 6:34
md.jamalmd.jamal
424519
424519
1
You need to analyze the termios settings of the receiving serial terminal, i.e.stty -a -F /dev/ttyUSB1, to see if echoing is enabled. It probably is, since it's commonly employed for normal canonical terminal communications.
– sawdust
Nov 13 '18 at 8:14
Vote to close: this isn't a programming question.
– sawdust
Nov 13 '18 at 8:16
I added stty command output. Can you please look
– md.jamal
Nov 13 '18 at 8:24
3
its because you have echo enable. trystty -echo /dev/ttyUSB1this will solve echo issue. credit goes to sawdust who asked for these stty logs. hope this solves the issue.
– Devidas
Nov 13 '18 at 9:20
After disabling all the -echo it solved the problem. Thanks sawdust, Devidas
– md.jamal
Nov 14 '18 at 6:52
add a comment |
1
You need to analyze the termios settings of the receiving serial terminal, i.e.stty -a -F /dev/ttyUSB1, to see if echoing is enabled. It probably is, since it's commonly employed for normal canonical terminal communications.
– sawdust
Nov 13 '18 at 8:14
Vote to close: this isn't a programming question.
– sawdust
Nov 13 '18 at 8:16
I added stty command output. Can you please look
– md.jamal
Nov 13 '18 at 8:24
3
its because you have echo enable. trystty -echo /dev/ttyUSB1this will solve echo issue. credit goes to sawdust who asked for these stty logs. hope this solves the issue.
– Devidas
Nov 13 '18 at 9:20
After disabling all the -echo it solved the problem. Thanks sawdust, Devidas
– md.jamal
Nov 14 '18 at 6:52
1
1
You need to analyze the termios settings of the receiving serial terminal, i.e.
stty -a -F /dev/ttyUSB1, to see if echoing is enabled. It probably is, since it's commonly employed for normal canonical terminal communications.– sawdust
Nov 13 '18 at 8:14
You need to analyze the termios settings of the receiving serial terminal, i.e.
stty -a -F /dev/ttyUSB1, to see if echoing is enabled. It probably is, since it's commonly employed for normal canonical terminal communications.– sawdust
Nov 13 '18 at 8:14
Vote to close: this isn't a programming question.
– sawdust
Nov 13 '18 at 8:16
Vote to close: this isn't a programming question.
– sawdust
Nov 13 '18 at 8:16
I added stty command output. Can you please look
– md.jamal
Nov 13 '18 at 8:24
I added stty command output. Can you please look
– md.jamal
Nov 13 '18 at 8:24
3
3
its because you have echo enable. try
stty -echo /dev/ttyUSB1 this will solve echo issue. credit goes to sawdust who asked for these stty logs. hope this solves the issue.– Devidas
Nov 13 '18 at 9:20
its because you have echo enable. try
stty -echo /dev/ttyUSB1 this will solve echo issue. credit goes to sawdust who asked for these stty logs. hope this solves the issue.– Devidas
Nov 13 '18 at 9:20
After disabling all the -echo it solved the problem. Thanks sawdust, Devidas
– md.jamal
Nov 14 '18 at 6:52
After disabling all the -echo it solved the problem. Thanks sawdust, Devidas
– md.jamal
Nov 14 '18 at 6:52
add a comment |
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1
You need to analyze the termios settings of the receiving serial terminal, i.e.
stty -a -F /dev/ttyUSB1, to see if echoing is enabled. It probably is, since it's commonly employed for normal canonical terminal communications.– sawdust
Nov 13 '18 at 8:14
Vote to close: this isn't a programming question.
– sawdust
Nov 13 '18 at 8:16
I added stty command output. Can you please look
– md.jamal
Nov 13 '18 at 8:24
3
its because you have echo enable. try
stty -echo /dev/ttyUSB1this will solve echo issue. credit goes to sawdust who asked for these stty logs. hope this solves the issue.– Devidas
Nov 13 '18 at 9:20
After disabling all the -echo it solved the problem. Thanks sawdust, Devidas
– md.jamal
Nov 14 '18 at 6:52