When USB activity is high the rate reading is sharply reduced. Typical is when Nano is first connected to a PC. The PC uses the usb to find and mount the Nano filesystem. Once that is complete rate returns to previous reading.
Added selection at top of menu to allow two ways of handling USB. First is to use it for charging only. Second is to shutdown data collection and allow host access to filesystem for spectrum files.
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Added selection at top of menu to allow two ways of handling USB. First is to use it for charging only. Second is to shutdown data collection and allow host access to filesystem for spectrum files.