The HLW8012 is single phase energy monitor chip by the chinese manufacturer HLW Technology. It features RMS current, RMS voltage sampling and RMS active power with an internal clock and a PWM interface in a SOP-8 package. You can buy it at Aliexpress for less than a euro a piece and the necessary components are fairly easy to source and quite cheap.
All in all it looks like a great IC to include power monitoring in your projects. I guess that is why Itead Studio chose it for the Sonoff POW, one of their newest home automation products. And of course I have a POW here in my desk and I’ve been playing with it this weekend. The goal is to support it in my Espurna firmware but first I wanted to know more about the HLW8012. I’ll write about the Sonoff POW in a different post later this week.