Method begin

src/modules/others/u2f.cpp:132–140

    U2fHidDevice() : _hid(HID_ITF_PROTOCOL_NONE) { USBHID::addDevice(this, sizeof(U2F_REPORT_DESCRIPTOR)); }

    void begin() {
        if (_started) return;
        USB.begin();
        _hid.begin();
        uint32_t t0 = millis();
        while (!_hid.ready() && (millis() - t0) < 4000) delay(10);
        loadState();
        _started = true;
    }

    void end() {
        if (!_started) return;