I recently received OneRNG free beta evalution kit from Jim.

Finally, I got some time to play with it at a Sunday Session of The Foundation makerspace.

Following the official documentation for the project I firstly took the ‘tin foil hat’ off the USB stick and checked which CC2351 I have in.

256k it is.

Put the ‘tin foil hat’ back on and plugged into an USB slot in my Ubuntu laptop.

Next thing, sudo su - into root so I can play with the device.

Checked where the device is:

/$ dmesg|grep ACM
[66017.968736] cdc_acm 3-2:1.0: ttyACM0: USB ACM device
[70837.767606] cdc_acm 3-2:1.0: ttyACM0: USB ACM device

Changed the permissions of the device next:

/$ cd /dev/
/dev$ ls | grep ttyACM0
crw-rw----  1 root dialout   166,   0 May  4 13:50 ttyACM0
/dev$ chmod 600 ttyACM0
/dev$ ls | grep ttyACM0
crw-------  1 root dialout   166,   0 May  4 13:50 ttyACM0

The idea is that only root can access the device ie. no one else can interfere with it.

Following ‘the white rabbit’ of the official documentation I do the next:

$ stty raw < /dev/ttyACM0  # put the device into raw mode
$ echo cmd0 > /dev/ttyACM0 # put the device into abalance/whitening mode
$ echo cmdO > /dev/ttyACM0 # turn on the feed to the USB

Installed rng-tools and stopped the RNG daemon that automatically started after the installation:

$ apt-get install rng-tools
$ /etc/init.d/rng-tools stop
Stopping Hardware RNG entropy gatherer daemon: rngd.