Wifi signal to distance

I am trying to get a precise distance of my imp from my router with the help of wifi signal strength .Is there any other way to do the same .Please let me know. And any reliable methods for the former would be of great help too … As Im a newbie to the world of imp please forgive me for my silliness…!

The signal strength is dramatically affected by obstacles, AP power, antenna types, reflections, orientation and a myriad of other things. Because there’s no way to know what’s affecting the signal strength it can only be used as a very rough measure of distance. If it’s only one AP you are interested then you can do a “site survey” and map signal strength against location. Often it’s multipathing due to reflected signals that limits the distance more than attenuation.

BTW corporate AP’s (and the AP’s in shopping centres) can triangulate and track wifi devices, which is why the latest Apple phones use random MAC addresses when looking for an AP, but I don’t think triangulation would be much help to you unless you had several AP’s.

I tried this formula to calculate the device from stack overflow
it does not seem to be even close to what the distance is i dont know the probem behind it
distance = 10 ^ ((27.55 - (20 * log10(frequency)) + signalLevel)/20)


As the Stack Overflow page eventually implies, you’re better off using triangulation than exact strength. Note that the routers you’re triangulating with don’t all have to be your own – the imp doesn’t need to join a wifi network to discover its signal strength. See imp.scanwifineworks().