A few more details regarding the PCB for connecting a WeMos D1 Mini to your Peacefair Pzem-004T. The PCB we use was designed as a generic board for various WeMos D1 Mini projects and therefore not all connections are used with the ESPproMon, so currently JP5 for example is not used. Partly because we don’t really like soldering but also to make it easy to swap parts in and out we don’t solder most of the components directly to the PCB. We expect you to populate the board with 3 and 8 way female headers and 3 way block terminals. If you prefer to solder the components directly to the board that is your choice.
The 4 way cable that connects from the TTL port on the Pzem to the ESP, marked A, B, C and D in the image above is not using the markings on the cable to indicate which pins it connects to on the ESP. For example the cable with the “+” markings is purely an identifier on the cable and doesn’t relate to the positive (3V3 or 5V) on the ESP. The actual connections are as follows:
- A = Pzem GND -----> ESP GND
- B = Pzem VDD -----> ESP 5V
- C = Pzem RX -------> ESP D7
- D = Pzem TX -------> ESP D6
In the next post we will provide details for the DS18B20 temperature sensor and the RF transmitter etc.