This is my first power/voltage sensor I've build. It is based on an commercially available powermeter from B+G E-Tech. You can find them on eBay or their website. It provides a 90ms pulse for each Wh flown through it.6Q7A7842

The line voltage is measured using a simple transformer and a circuit based on the schematic from OpenEnergyMonitor. The software to measure the line voltage is also from OpenEnergyMonitor embedded into my sensor framework.

As this was my first power sensor, I mounted the hardware into a sturdy BOPLA ULTRAMAS case with a Schuko socket on top for the load and a fixed power line cable for the source.

The microcontroller is a PretzlBoard (an Arduino clone with onboad ESP8266 WiFi). Powered is all by a completely oversized 5V/3A siwtching power supply from MEANWELL - but it costs only €8,- ;-)

The data is transmitted also directly to the data collecting web-site.The power and voltage values are sent every minute to the web-site. The administrative sensor are transmitted once every 10 minutes to the web.


Gehaeuse 1 Vorne res

InnenBeschriftet res Schematic


The following sensors are provided by this sensor node:

01-09-2016 11-44-33

Uploads OK Number of successfull data uploads
Network restarts Number of WLAN reconnects etc.
Uploads failed Number of upload errors since the last WLAN reconnect
 VCC The internal power supply voltage
Netzspannung The main power peak-to-peak AC voltage
Gehäuse The inner case temperature
Energieverbrauch The energie consumption of our house during the last measurement intervall, means 1 minute

Visualization is identical to this powermeter.

2014 CW (Morse Telegraphy) was added to the German Nationwide Inventory of Intangible Cultural Heritage.