Avoid using Softserial for GPS Rescue as it’s too slow. You may use it to display GPS related info on the OSD, but it’s simply not reliable enough for GPS Rescue. It’s best to use a hardware serial port (any TX and RX pins on the FC), and set baudrate to at least 57600....
The center focus is the wheel or the knob that's located in the center of the binocular, usually somewhere in between the two barrels where it's easy to use with either the left or right index fingers. Ideally, it should be rather large in size with knurly or well-serrated grooves to...