@disco78 We recommend using a joystick to play in Recalbox, using it exclusively with the keyboard is not recommended.
With the Joystick, to access the Retroarch menu just press Hotkey+B (based on the SNES joystick).
You can use the Virtual Gamepad (even on smartphone), see:
If you're stuck from startup, try hooking up a USB keyboard and navigating to menu->controller settings->configure a controller. Then you may be able to push a button on your gamepad, initializing the configuration process. While you're in this screen, you can also try cycling through your inputs for "Input p1" to see what appears. If nothing is there other than "default", then the pads really aren't getting detected.
Also wired or wireless? If wireless, try checking to see if the wireless dongle actually works by testing it on your PC or another system. Try connecting using different USB ports on your system also, as sometimes these can go bad.
These are basic suggestions, so apologies if you've already tried this stuff. Without more details though, no one can really know what you have or haven't tried.
I have a GameBoy Zero (with Rpi3b) and buttons soldered to the GPIOs.
So sorry, but I don't really get what you did and why it was necessary compared to regular GPIO... but as I said I don't know much about taht.
Besides all links you provide are for retropie, and recalbox is not retropie...
If someone used the same setup goes through here, he might be able to help you, but I don't know more than that.
Danke euch. ja habe die Pi 3B + sogar. und da ist ja RecalBox noch "Beta" nervt bissel dass das nicht geht. nein habe leider trotzdem nur einen controller drinne. und ach komisch ist das die beiden controller die selbe MAC Adresse zu haben