A 4-Channel mains sensor with an option for either a Wemos D1 Mini or an ESP-12 WiFi module. This board uses the ESP8266's on-board A/D (12-bit) with an external multiplexer to select the channel to be read.
Using the ESP8266's own A/D (10-bit) to measure the output of the current transformer, this version measure the peak values of the mains sine wave then calculating the RMS voltage value.
This is based of the EmonLib https://github.com/openenergymonitor/EmonLib library. This works different from version 1 and as some digital filtering which improves resolution at lower power levels.
