I want to transmit my own signal.
Since iio:device4 is TX, we can copy binary file to /dev/iio:device4 as below.
cp signal /dev/iio\:device4
Then if we do echo 1 > /sys/bus/iio/devices/iio:device4/buffer/enable, we can send signal.
However, when I give a command "cp signal /dev/iio\:device4 ", it is giving following error. I remember it worked me once previously but I do not remember how it worked ? (Signal is a binary file)
cp: writing 'dev/iio:device4': invalid argument
cp: failed to extend 'dev/iio:device4': invalid argument.