Howdy folks -
I have a little app
which opens /dev/ttyS2 and reads NMEA data through the serial port. This
application works fine while the usb cable is plugged in. But as soon as the usb
cable is removed, it stops receiving serial data through ttyS2. If
the unit is booted with no usb cable connected, it also doesn't read any serial
data. However, if the usb cable is plugged in again, it starts receiving data.
Am using the
following in a startup script (/etc/init.d/S99Serial) to configure the serial
echo AF1 in >
echo AF1 out
/dev/ttyS2 ixoff clocal ixany -ixon -echo -echonl ospeed 4800 ispeed
My program uses
open("/dev/ttyS2",O_RDONLY) to open the port, and read() to read 1 byte at a
time. Nothing special.
I don't get it. I
don't even have to log on using USBNET and ssh - as long as the cable is plugged
in to the usb port, it seems to work. Not connected, no work.
I'm using a gumstix
basix using the minidin connector.
Any advice really