For his MPPT, [Debasish] is using an Arduino Nano for all the math ... is connecting the entire controller to the Internet with an ESP8266 module. It’s a great example of building something ...

[Don] is using an Arduino nano to monitor the alarm signal ... Once the Arduino detects a signal, it uses an ESP8266 WiFi module to send an email. The address [Don] used is the email-to-SMS ...