The idea here is to use as less components as possible to do something useful, for two reasons:

  1. concentrate on software (you can do almost everything)
  2. reduce power consumption at a minimum level: 50 uA while deep sleeping and 120 mA for just 2-5 seconds during WiFi transmission.

In my case I got:

  • WiFi hostspot to configure WiFi
  • WiFi web server
  •  temperature measurement using DS18B20 
  • power supply voltage measurement by the internal ADC