localStorage.baud is only set when changing the baud rate menu, so when that has never been done the page tried to connect with a baudRate undefined, despite showing the default value of 9600. Fixed by testing if localStorage.baud is undefined in port.open.
localStorage.baudis only set when changing the baud rate menu, so when that has never been done the page tried to connect with a baudRate undefined, despite showing the default value of 9600. Fixed by testing iflocalStorage.baudis undefined inport.open.