If you read the posts about my XPEnology webserver you mayby know that plans where to find out how much power my “cheap” webserver was consuming. I’ve got a good feeling about power consuption but as we Dutch say ” meten is weten “.
The only way to know for sure is to measure and log energy consumption, preferably under different server loads/conditions.
As core for my project I wil be using a china energy meter type DDS238-2 ZN/S as shown in the picture above. One could measure power consumption by only using this meter but i would like to use it’s modbus feature to do some more detailed logging and probably connect it to my domotics system. I know you can buy lots of ready to use wifi energy meters but for me this is a nice oppertunity to get some ESP32 practice.
To use this meter safely and add the additional electronics, first thing was to print a suitable casing.
To make logging possible I needed some additional parts and I decided to add a realtime clock, modbus to serial convertor, a small switched power supply, a fuse and a ESP32 as microcontroller and for coms.
The ESP32 model I’m using is a TTGO model T8 wich has a onboard SD card slot that could be used for stand-alone logging, storing some web pages, etc .
Follow-Ups of this post wil discuss hardware software and web interfaces in more detail.