ESP8266 Gizmo to connect to the strongest open Hotspot
More information at http://benlo.com/esp8266/esp8266Projects.html#hotspotfinder
Open Hotspot finder
My goal was to create a simple hand held hot spot locator, which would quickly tell me if I can connect to one of the several WiFi routers around our home from any given location. If this works, then I can create other IoT gizmos that automatically seek out the strongest signal and connect to them automatically. My WiFi access points do not require a password.
In most cases, the use of a device like this to connect to a WiFi hotspot requires the authorization of the owner of the access point. Please only use this code to access hotspots which you are already authorized to use.
No connections are needed to the board, other than the usual TXD, RXD and ground for programming. This board comes with the battery already wired.
When power is applied to the board, the program searches for access points that are in range and chooses the strongest one that is open and does not require a password to connect. If it finds any open access points in range, the LED changes from RED to BLUE.
Hotspot finder then attempts to connect to the access point and, once connected, it sends a query to a php script on a web site. If the expected response is received, the LED changes from BLUE to GREEN.
If a response is received, but it does not match the expected response, it indicates that there may be an additional login required, or the access point is not connected to the internet, and the LED changes to PURPLE.
After 5 seconds, the LED goes off. If power is left on, the finder tries again in 30 seconds.
Experimentation has shown that a connection can be established and verified in less than 3 seconds.