Power Monitoring Update

So, after a… while… I finally got around to getting this project together.

Below, a quick picture of the completed and populated board. This required quite a bit of soldering, and I discovered a couple of problems during testing (hey, it’s supposed to be  a learning experience!).

The Teensy 3.2 and the ESP8266 are removable – they have plugs for all their pins.

So the finished board has 12 inputs. The board size is the limit of the free version of EAGLE. On the back is where you’ll see some airwires (aka mistakes).

Two airwires – one because I forgot to route a pin from the Teensy 3.2 to the ESP8266, and the other because I may have fried one of the input pins on the Teensy trying to get the device powered from AC.

So when I was designing the board in EAGLE, I knew a lot less about circuit design than I do now (especially AC power). During testing, I discovered that powering the circuit via AC isn’t really that feasible for high currents (the ESP needs >200ma). Not only does the taking power from the AC-AC transformer deform the AC waveform slightly (affecting measurement), you also must use a separate ground for the ADCs.  Oops. Here’s some blog posts describing this –  here and here.

I haven’t yet uploaded the code to my GitHub account – that’s coming in a future update on the code that supports this project.