In this instructable i will show you how you can easily make a wi fi network scanner with an esp8266.
Esp8266 wifi device scanner.
Last month i wrote a series of posts about reducing the power consumption of the esp8266 showing how i got the power consumption of a weather station down to 54 μah per 5 minute reporting cycle.
Such a device can be used as a troubleshooting tool to determine if the suspect router is transmitting a wireless signal.
The objective of this post is to explain how to scan the surrounding wifi networks with the esp8266.
To show how this kind of tracking works we can program a nodemcu in arduino to sniff the air for packets from any device we want to track turning on an led when it s detected nearby.
This project is to create an open wifi scanner which will indicate visually by an led when there is an open wifi i e a wifi without password or wifi without authentication.
Scan to connect a mobile phone to a hot spot you typically open wi fi settings app list available networks and then pick the hot spot you need.
This instructable however can easily be done with any other module.
You can also list the networks with esp8266 and here is how.
The esp8266 wi fi soc microcontroller an analog meter ammeter and an led.
The nodemcu is the easiest way to program and experiment with esp8266controllers.
The construction of the scanner is simple in design and only requires three main components.
Smartphones and other wi fi enabled devices send radio signals called probe frames to locate nearby wireless networks which makes them easy to track by listening for their unique mac address.
Esp8266 nodemcu wi fi scanner allows you to easily locate visible wireless networks and its corresponding information.
Include esp8266wifi h void setup serial.
This sketch demonstrates how to scan wifi networks.
This program obtains the network name ssid signal strength rssi and mac address security.
Set wifi to station mode and disconnect from an ap if it was previously connected.
Wi fi scanner is useful for normal access point users who need to find out the signal strength distribution for their wireless network at home or choose a position for their access.
At the end of that i thought further improvements would be mainly tweaks and fine tuning but tobias wrote a comment explaining that it would be possible to avoid the initial network scan happening.
Here an led is connected to the gpio pins of esp8266 01 and it is used for the indication of open wifi availability led will be blinking while searching for an open wifi led will be on continuously when an open wifi is.
The code for this tutorial will be very simple and since we only want to scan and get some information about the surrounding wifi networks we will do all the coding on the setup function.
