Is there a way to have cpuminer automatically find all of the Gridseed 5-chip devices rather than specify each one via the --gc3355=/dev option?
If you're on Linux, you can use this command:
minerd -o stratum+tcp://pool.com -u USERNAME -p PASSWORD --gc3355-autotune --gc3355=`ls -m /dev/ttyACM* | sed -e 's/, /,/g' | tr -d '\n'` --freq=1200