i have designed a custom arduino board with the arduino nano schematic. I followed the schematic carefully and everything is okay.But if i connect the board to my pc, i keep seeing this error “unknown usb device (device descriptor request failed)”. I have attached the picture of the error message. if i program the board using ICSP using another arduino as a programmer, the board will work well. So i guess it may have to do with usb serial bridge. i used FT232R in my design. I have tried many solutions on the internet but non is working for me yet. I will appreciate if anyone has solved this problem before to help me out. Thank you.