only a code trunk

if you didn't know witch I2C bus or witch I2C address. you can user 'i2cdete -r ?' to scan x I2C bus. after you know the I2C bus and I2C address. you can test it like follow:
python i2ctest.py 1 0x22 1024 32

before test, you may ready the can bus. the follow is set can0 bus to bitrate 250kbps
bash readycan.sh 250000
then test can0 receive performance:
./cantraf
after BeagleBone Black is ready to test, you can device( a nother can bus device) can send data to BeagleBone Black( wire link is necessary).

of course, you can test send ( or transmition) performance:
./cantraf 1024 the, BeagleBone Black will send 1024 bytes data to you another can bus device.