An Open WiFi Detector with ESP8266

If you have a NodeMCU ESP8266 v1.0 you probably know it's the perfect little size for IoT projects. This LiPo backpack makes very easy the charge of a LiPo battery instead of soldering more boards, this little PCB sits on top of the NodeMCU ESP8266 v1.0 and allows a LiPoly/LiIon battery to plug in. When the NodeMCU ESP8266 v1.0 USB port is powered, the battery is recharged automatically. Unplug the USB port and the NodeMCU ESP8266 v1.0 will switch over to the rechargeable battery.

This backpack is the first one designed for the module NodeMCU ESP8266. Automatic switch between charge and use of the battery.

The material we need to make our open WiFi detector is:

Cause we want to have access to the sleep mode of the ESP8266 our connection diagram is the next, a very simple circuit but necessary, connect the RST pin to the GPIO16

Once that connection is done, its time to program. the necessary code to make our WiFi open detector works is the next, it was developed for The IDE of the Arduino with the module ESP8266.

Once uploaded the sketch on the ESP8266, the LED will blink when it found's an open wireless net and it will go through sleep mode, also you can see by the serial monitor each one of the WiFi's found.

Thanks to my friend wero by his support to get done this guide