Okay, FSS, in beta I used all of mouse and keyboard, joystick (and keyboard, but HOTAS should work), and gamepad. They all work, a two-stick gamepad might be best, but I don't like swapping controllers all the time, found mouse a bit less cumbersome than joystick.
First point: FSS is in a completely different control mode, so you can largely use controls that are already bound to other things in normal flight. You'll need one button to enter it.
Finding bindings, it's got its own section near the bottom of the controls menu.
FSS simplest approach involves moving the camera around, tuning to get the arrows to signals and zooming in on them. What to bind:
- scrolling/camera: moving around, either bind stick axes as you like or adjust the mouse settings to your liking (or both). Treat it like a turret or a ship.
- tuning: probably the most crucial. I mainly use keyboard keys bound to tuning increase and tuning decrease, holding them down tunes fast, tapping makes small adjustments. Controller buttons that will repeat have the same effect (my joystick trigger doesn't), some people have used the paddle control on the thrustmaster throttle for example, which is nice as it self-centres. You can bind as an axis instead, this is good with a gamepad stick, or you can bind to an absolute axis for use with a throttle, I'm not a great fan of that, but only have the throttle control on the back of the T16000m, so might be better with a more substantial one.
- auto-zoom: Your main way of zooming in on bodies, you need to bind an in and out, it can be put on an axis, for example a two-stick gamepad it could be the same stick as tuning, but you don't want to accidentally tweak tuning while using other controls.
- step zoom: I found I needed this in beta more, if signals were close together then sometimes auto-zoom wouldn't work unless you step zoomed in first a little to separate them. However I don't think that's happened to me in the release version. Bind these to buttons.
- honk! You can honk from analysis mode in flight, I usually do. If you forget to before you enter FSS there is a dedicated honk binding (FSSDiscoveryScan) so you can do it from within FSS
- exit: you'll want to leave FSS eventually. You could quit the game, but it's easier to bind a key or button. It can be the same one you use to enter FSS. The mode switch key remains active, so you can also leave by switching back to combat mode.
In practical terms:
keyboard and mouse, I've got mouse on pitch (inverted) and yaw, tune down/up A/D, zoom out/int S/W, step zoom out/in Q/E - these are all together and happen to correspond to my throttle and lateral thruster controls. Honk is mouse 1, quit is the default '.
gamepad: one stick for camera view, the other for tuning (left/right) and zoom (down, up), main trigger honk, step zoom I think I had on face buttons.
joystick: used this least, but stick for camera control. Experimented with twist used for tuning, but too often moving the stick would shift it. Stuck with the keyboard choices for the other controls, but hat will work for zoom in out with other buttons for step zoom.
edit: actually finding things: move around the orbital plane (only circle shown to start), adjust tuning to one of the clusters on the tuner and when you start to see arrows, move towards them. Near matches will be dashed circles, fine tune until you get a solid circle, you can now auto-zoom. You'll either get the body or move in a zoom level (because there are other signals close) and need to point at the one you want, in this situation after getting it, don't necessarily zoom all the way back out, just locate the other object. If you find a gas giant, go back a zoom level after it's scanned and tune down to find the moons if you want them. Sometimes you can't tune to the signal for smaller bodies until the larger one has been scanned. If you're on an object, tuned to it, but auto-zoom isn't working, step zoom in a bit. Potential signal areas will show as stronger blue oblongs, so look out for these as you move around and maybe try the different tuning bands on them if you're having trouble. If you've got one body you just can't find, have a look out of the orbital plane, I found one planet orbiting at 90 degrees tonight.