Another modification in mbng_file_c.c is required where the number of CS lines is hardcoded (actually you should have seen the error message...) I put an example which works at my side into the demo/mbng_ainser_with_3_cs branch, see: https://github.com/midibox/mios32/commit/ac6151ea7012e2b3e5e6a15575b4c4f92c8ffe2f Best Regards, Thorsten.