Current version: SlimmeLezer v1.1.0
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.
Not all pins are soldered..?
Normally I used to solder all pins, used or unused. Yet if you look closely, you can see that only the GND, 3V3 and D7 pins are soldered. Why? Because of the repairability. This year I’ve sold about 300 WiFi readers, of which 2 didn’t work. Then replacing the Wemos ice not an easy task when all 16 pins are soldered.
The only pins I use in version 1.1.0 are the 3v3, gnd and D7 pins. Soldering only those pins and leaving all other pins unsoldered seems to be solid enough.
So please don’t see it as a mistake, it’s intentionally done.