How to build an open WiFi finder using ESP8266 and two coin batteries
Stevica Kuharski

What suprises me about this is that the current demand for an ESP8266 (60–20 mA) is much higher than the battery can provide (3 mA steady to 9 mA pulse). Did you use a capacitor to store up energy for that?

I’m trying to create a sensor to send and “is open” or “is closed” signal every time a switch changes from off to on or on to off. I want to make it small so a couple of button batteries sounds great, but I’m not seeing how it will work.