R305 not working with hardware serial but works with software serial

i can't use hardware serial with my r305 fingerprint but it works fine with the software serial on my arduino uno

@mayor3570

Welcome.

Please read the forum instructions and provide a lot more information. As it is your question is impossible to answer.

Thank you.

Got a question?

An Uno only has one hardware Serial port so if you are using it for your r305, you can not use it to print debug messages, etc to the Serial Monitor. Without seeing your code, who knows?