Das sollte nach ein paar Impulsen so aussehen:
pi@raspberrypi:~ $ stty -F /dev/ttyUSB0 300 raw
pi@raspberrypi:~ $ strace -ttt -e read cat < /dev/ttyUSB0
1455875482.943606 read(3,
"\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0h\5\0\0004\0\0\0"...,
512) = 512
1455875482.945117 read(3,
"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"...,
960) = 960
1455875482.945948 read(3,
"A.\0\0\0aeabi\0\1$\0\0\0\0056\0\6\6\10\1\t\1\n\3\f\1\22\4\24"..., 47) = 47
1455875482.947916 read(3,
"\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0L\204\1\0004\0\0\0"...,
512) = 512
1455875482.948871 read(3,
"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"...,
2840) = 2840
1455875482.949692 read(3,
"A.\0\0\0aeabi\0\1$\0\0\0\0056\0\6\6\10\1\t\1\n\2\22\4\23\1\24"..., 47) = 47
1455875482.954134 read(0, "\0", 131072) = 1
1455875491.653205 read(0, "\0", 131072) = 1
1455875493.989435 read(0, "\0", 131072) = 1
1455875495.062248 read(0, "\0", 131072) = 1
1455875496.187496 read(0, "\0", 131072) = 1
1455875497.308985 read(0, "\0", 131072) = 1
1455875498.213774 read(0, "\0", 131072) = 1
1455875498.434906 read(0, "\0", 131072) = 1
1455875499.527885 read(0, "\0", 131072) = 1
1455875500.413185 read(0, "\0", 131072) = 1
1455875500.610403 read(0, "\0", 131072) = 1
1455875501.704031 read(0, "\0", 131072) = 1
1455875502.871774 read(0, "\0", 131072) = 1
1455875503.939560 read(0, "\0", 131072) = 1
1455875505.087093 read(0, "\0", 131072) = 1
1455875506.163666 read(0, "\0", 131072) = 1
1455875508.634046 read(0, "\0", 131072) = 1
1455875509.749251 read(0, "\0", 131072) = 1
1455875510.873394 read(0, "\0", 131072) = 1
1455875511.969812 read(0, "\0", 131072) = 1
1455875513.135178 read(0, "\0", 131072) = 1
Vielleicht greift die udev-Regel nicht?
Schau mal in dmesg bzw. syslog nach.
Gruß
Udo
Am 19.02.2016 um 10:19 schrieb Udo1:
Am 19.02.2016 um 10:08 schrieb Volker:
root@raspberrypi:/home/pi# stty -F /dev/Gas-lesekopf 300 raw
root@raspberrypi:/home/pi# strace -ttt -e read cat < /dev/Gas-lesekopf
1455872300.543365 read(3,
"\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0h\5\0\0004\0\0\0"...,
512) = 512
1455872300.546973 read(3,
"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 960)
= 960
1455872300.550576 read(3,
"A.\0\0\0aeabi\0\1$\0\0\0\0056\0\6\6\10\1\t\1\n\3\f\1\22\4\24"...,
47) = 47
1455872300.557020 read(3,
"\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0L\204\1\0004\0\0\0"..., 512)
= 512
1455872300.560159 read(3,
"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 2840)
= 2840
1455872300.563438 read(3,
"A.\0\0\0aeabi\0\1$\0\0\0\0056\0\6\6\10\1\t\1\n\2\22\4\23\1\24"...,
47) = 47
1455872300.575751 read(0,
Das war der Vorspann. Musst du schon länger laufen lassen.
Gruß
Udo
