I don’t know anout the IO pins but there is a download link for firmware on the wiki at: seeedstudio.com/wiki/index.p … tor_Driver
These are the links it gives (just check under the section that says ‘Resources’):
Resources
L298 dual full bridge driver - st.com/stonline/books/pdf/docs/1773.pdf
AMS 1117CD 5v voltage regulator - advanced-monolithic.com/pdf/ds1117.pdf
Eagle files of I2C motor_driver - garden.seeedstudio.com/images/7/ … v0.92b.zip
File:Grove-I2C Motor Driver firmware.zip - garden.seeedstudio.com/images/7/ … v0.92b.zip