root@trb-dev:/home/mod6/fg4# stty -F /dev/ttyUSB0 115200 raw -echo -echoe -echok
root@trb-dev:/home/mod6/fg4# dd iflag=fullblock if=/dev/ttyUSB0 of=fg4.fg1.bin
^C2196682+0 records in
2196682+0 records out
1124701184 bytes (1.1 GB) copied, 148892 s, 7.6 kB/s

root@trb-dev:/home/mod6/fg4# ent fg4.fg1.bin 
Entropy = 8.000000 bits per byte.

Optimum compression would reduce the size
of this 1124701184 byte file by 0 percent.

Chi square distribution for 1124701184 samples is 285.64, and randomly
would exceed this value 10.00 percent of the times.

Arithmetic mean value of data bytes is 127.4988 (127.5 = random).
Monte Carlo value for Pi is 3.141897002 (error 0.01 percent).
Serial correlation coefficient is 0.000041 (totally uncorrelated = 0.0).
root@trb-dev:/home/mod6/fg4#