I do the IT for a small not for profit club. They want to have wifi over an open area of about 200m radius and need to control about 500~1000 wifi devices for an event.
To do this we will need quite a number of low cost wifi units like probably 10~20 of them, this sort of dictates low cost units off aliexpress or similar. I did get a xiaomi 3g and installed openwrt on it but I see its classed as "unstable" as the wifi unit locks up occasionally. So what I am looking for a something like the $30US xiaomi, of good quality but I can put a stable version of openwrt on it.
If possible then something to manage these 20 openwrt units centrally?
I think that your choice of number of APs, channels, and how you handle the backhaul will be much more important than the specific devices you use. There are many opinions and recommendations in the long thread
"Central management" isn't something that OpenWRT has focused on, typically being used by individuals with a handful of APs at most. I'd suggest looking at rsync and some shell scripts to "customize" the options for each AP.
I'm assuming you need that many APs for sufficient signal strength over the area, not as an attempt to increase throughput.
With that many APs in a relatively small area, you'll need to apply enterprise-style channel allocation to reduce the impacts of the APs colliding with each other. That is the nature of 802.11, not the AP hardware. Both beacons and the communication itself will collide, potentially reducing your overall throughput significantly.
If possible, check Ubiquiti and spend your money on their cheapest cloud capable router. It will save you a lot of headache. Look for second hand aswell.
We use them here a lot behind gluon (openwrt fork) capable routers to be able to manage big amounts of clients in our Freifunk "Hotspots". The possibilty to use a controller is great. Host it on a vm or small dedicated machine.
Hi, Yes I like ubiquiti equipment a lot. What I have settled on (more of less) for the access point(s) is a GWN7600LR. 1 to 3 of them connected by ubiquiti p to p units to give us the distances as the field is 1km long.
I can do KVM backed up with gluster no problems, I will have a look at gluon.