First of all, i have never used OpenWrt and still a newbie on linux and network configuration. But, i need something a bit special for a client. At work, we design and build all sorts of wastewater pumping stations and potable water distribution. And for one client in particular, we are building mobile units that goes all around the world. I need a router that can be used as a wifi client mode, which mean i'm having my own subnet, dhcp and routing table, but if wifi signal is not strong enough in this particular place, they will be running an ethernet cable and plug it into the wan port.
I'm wondering if it is possible to configure OpenWRT to be able to accept either of wifi (in wifi client mode) but also thru the wan port. Both would need to be on DHCP on the wan side, and i would have my own lan subnet. On top of that, i would really like not having to change the configuration whether it is wifi or wan port and have it fully configure to accept both because it might be different from place to place.
I hope my explanation are clear enough and really hope there's a way to do this.
The AR750S ("Slate") is a better router than the excellent AR750 you linked. It offers GigE ports, a QCA9563 running at 775 MHz, and 128 MB of NAND flash (supported by GL.iNet firmware, waiting for Linux 4.19 for "native" OpenWrt support).
I have two of the AR750S and the build quality is excellent, as is the firmware that GL.iNet supplies. GL.iNet's latest firmware is based off OpenWrt 18.06.1 and has additional utilities on top of a pretty much "stock" OpenWrt buiild.
I don't completely understand your configuration, but it seems like a "travel router" application, where upstream connectivity is supplied either by an Ethernet cable, or over 802.11. If so, either the GL.iNet firmware, or OpenWrt with something like the Travelmate package should handle that.
I don't know your quantities, but GL.iNet OEMs devices as well.
Yes, you should be able to "pre-program" both the SSID to which you would connect, as well as that which the AP will offer in the config files on the device.
Thank you very much for you're quick response and help. Greatly appreciated, i will probably need more help if I end up using openwrt. I will order the router you suggested.
Yes of course it would be better!! But for the purpose of it, it's not mission critical and the lack of space to mount it properly make the decision to use small and cheap appliance. Although, if you have in mind an industrial equivalent, i would be interested to give it a look!
I think it's only a number of manufacturer that knowledge OpenWrt support (or rather that their firmware is based on OpenWrt)--at least this is the case for consumer routers.
I think you could be limiting your choices if you look for outdoor routers. A different approach would be to have outdoor APs/repeaters, connected to a router of your choice that's installed indoor.