Archived version: v3.0
The wireless P1 reader is based on an ESP-12. It has a build in logic inverter which makes the data from the P1 port readable for systems like Home Assistant, DSMR-reader, Domoticz, P1 Monitor and other systems.
The ESP-12 has a build in inverter, yet not all firmware can use that functionality. Therefore the reader has a logic inverter to make it accessible for everyone.
The modules are designed to work with DSMR 5. Working with DSMR 5 means that the Smart Meter can deliver enough power through the P1 port to power the reader. Therefore no extra power adapter is needed to work.
The module is compatible with older Smart Meters, having DSMR version 2, 3 or 4. As older versions of DSMR can’t provide enough power through the P1 port, an external power source is required to work. That can be any micro USB adapter which is capable of delivering 250mA.
Special version: The Compact version
There is a special version, a compact version. This is the version I started with and recently got a new upgraded design. As the model mentioned above is more commonly sold (easier to program yourself via usb) than this version, I wanted to make a last version as tribute to the model it all started with.
This model is design to be used for DSMR 5 only. There is no USB port for external power. There is however two through holes for feeding external 5v. Yet is it recommended to use the Wemos version for older Smart Meters with DSMR 2/3/4.