Few things are as frustrating as a WiFi signal that drops in and out. On a public network it is bad enough but at home? Even if you can live with it, your cohabitants will certainly impune your technical abilities if they don’t have solid WiFi. One solution is a WiFi repeater. You can buy one, of course. But you can also make one out of an ESP8266 and some code from GitHub. There is also a video about the project, below.
[Martin Ger’s] code implements NAT, so it isn’t a true WiFi repeater, but more of a bridge or router. Of course, that means performance isn’t stellar, but tests show it can sustain about 5 Mbps, which isn’t bad for a little board that costs a couple of bucks. There is a limit of 8 clients, but that’s more than enough for a lot of cases. Even if you don’t want to use it as a router, it has a mesh mode that could be a basis for some interesting projects all by itself.
There is a web-based configuration for common setup, and a console on port 7777 or the serial port to do advanced things like port mapping or static DHCP addressing. There is a simple firewall and — of particular interest — an MQTT client built-in.
Another neat feature is the optional automesh mode that lets several of the repeaters self-organize. To do this, [Martin] needed a way to know which repeaters were close to the “real” WiFi. When in this mode, the repeaters actually mutate their MAC addresses to provide this information. This is an unusual solution, to say the least. The MAC addresses all start with 24:24 to avoid other devices, but it is odd for a device to dynamically change its MAC address. Or maybe its creative, we couldn’t decide.
If you just want to extend your self-made RS232 network, you can still use an ESP8266. This isn’t, of course, the first ESP8266 we’ve seen substituting for a commercial consumer product.