I got this reply from the fitzwilliam museum.
They were so helpful and I'm really thankful to all those who help
"Thank you for your enquiry.
Your coin is a billon dinero of Joanna and Charles (1506-1516) from Barcelona.
The obverse inscription begins after the crown of the bust IOA. KAR. OLV, and the reverse reads BA/CA/NO/VA.
Catalogue no. 2974. Ref. Adolfo, Clemente y Juan Cayon, Las Monedas Espanolas (Madrid, 2005)
Best wishes,
Richard"