The data from the usb_data are NMEA data so it's ascii. The usb_data on debugger is "4 where it supposed to be a line of numbers. If i use qDebug() << lat_mid.toLatin1().toHex();
the output is “34003000340035002e003800390032003100” but if i use qDebug() << lat_mid.toLatin1(); the output is “4. I know that the bytes are 60 byte long because i'm
sending them from a uC. And i'm using a Qtextedit to show these variables, something like a console.

On the console i'm seeing
latitude 40.705465,E
longitude -74.026566,S
lat_mid 40.705465
lon_mid -74.026566


but the qDebug is showing only the "4 on the latitude variable. There must be non-printable characters because what i'm trying to do is to convert a string to double.