Greetings,

I have a use case where I need two WIFI access points on the same LAN network with an approximate 30-50m distance between them. One connects to a hardware device (which is not connected to the internet, we do not need internet connection) and we use the network to use and manage that device through a mobile app on both sides where access points will be mounted. A friend recommended Mikrotik wAP ac r2 RBwAPG-5HacD2HnD to me saying we should use 5g to make a bridge between both mikrotik units and 2.4g for wifi.

In the past we only had one cisco or netgear router and it was fairly easy for me to set it up, but now we had to exapand to two AP to avoid bad signal and connection drops in the app. My problem now however is that I am completely new to Mikrotik user interface and have no idea how to set this up, nor have I found any instructions related to my issue that would help me solve it. I'd kindly ask if anyone is able to provide help on this matter.

One of the many possible setups:

wAP1: used as AP on 2.4GHz and as AP for the 5 GHz link. This wAP1 is also the DHCP server and has all other network services as needed (e.g. DNS...)
wAP2: used as AP on 2.4 GHz and as client for the 5 GHz link. This wAP has no extra services in this setup.
The whole network is bridged as just one transparant L2 network.

wAP1:
- set wlan1 as AP, set all needed 802.11 parameters
- set wlan2 as 5 GHz "AP-bridge" mode
- add wlan1,wlan2,ether1 to a software bridge
- set DHCP server on that bridge if needed. All services are set on the bridge only !

wAP2:
-set wlan1 as AP (can be different or equal to the wAP1 settings)
-set wlan2 as 5 GHz "station bridge" mode (!!!) , set security profile and scan for the "AP-bridge" and connect
-add wlan1,wlan2,ether1 to the software bridge
-set DHCP client on the bridge (or give a static IP address to the bridge, used for management only)

Connecting to wlan1 on wAP1 or wAP2 will be transparant as one network. No firewall rules are needed, unless some ethernet connect to the internet.
The modes "AP bridge" and "Station bridge" are Mikrotik specific modes. This "bridge" feature avoids the need for using WDS.

PS advanced:: 5 GHz could be used as AP on wAP2 also, if a virtual wlan interface is created with wlan2 as master , and an AP is configured on the extra wlan. Add this extra wlan also to the bridge.

Is this in a building, or in free space?
How high up are they?
Is there a lot of interference on 2.4GHz in the location?
Can your mobile devices use 5GHz WiFi?
What sort of speed does your application require?

Depending on your answers, you may find it more reliable to use 2.4GHz for the PtP link and using 5GHz for the links to the individual mobile devices.
A 5GHz signal will be attenuated more in free space than 2.4GHz signals so with the same TX power, the 2.4GHz signal may be better suited to longer range links depending on whether there is a lot of interference in your location.