When you need to connect a non WIFi device to a network, or when you need to create a mobile control network the Mikrotik mAP 2nD is the answer. It has a built in access point and two CAT5 ports.
It runs routerOS and can be configured for many solutions. For example, when you need to control a mobile mixing desk like the Allen & Heath Qu-SB.
When you are out on gigs the Qu-SB is a great 16 channel mixing desk but you need a reliable Wi-Fi connection and cant always rely on the venue to provide it. The Mikrotik mAP 2nD can be configured to bridge all of its ports together and act as a dedicated access point. It’s small enough to Velcro to the back of the Qu-SB and powerful enough to give you a secure dedicated network and even connect a second device such as your lighting controller.
Here is Andy Morrison explaining more.
The clever bit of course is the programming of the device to act in this way, but the Mikrotik itself is a £35 device!