Here you will find a detailed quick guide.
In order to enable the hotbits production on the RaspberryPi, you need to enable this feature with a small script. Please insert the commands one by one and if you have any problems let me know.
sudo apt-get update
sudo apt-get -y dist-upgrade
sudo rpi-update
sudo reboot
sudo apt-get install netpbm
sudo apt-get install rng-tools