Based on the document from butterfly labs here:
I am using my ASIC miner successfully under ubuntu.
However I want to start BFGMiner on startup. This is where the fun starts.
in order to get BGFMiner to recognise the device i need to run
sudo chmod 666 /dev/ttyUSB*
after that I can run BFGMiner as follows:
bfgminer -o miningpool:port -u username.workername -p workerpass
When I try and put these commands in rc.local or in a script which i call via rc.local, BFGMiner starts but it seems like the chmod function isn't working. BFGMiner doesnt detect the device. The process is started by root. If I kill it from my user, and run the exact same script i am calling via rc.local, then it works. I've also removed the password requirement from both root and my user in the sudoers file, so it isnt that.