The ``pzem004t`` sensor platform allows you to use PZEM-004 (version with 8-segment screens, `website <https://www.instructables.com/Power-Peacefair-PZEM-004-ESP8266-Arduino-Nano/>`__) and PZEM-004T V1 energy monitors
These devices have optocouplers on the UART port and the resistors mounted on the board have been designed to work with 5V devices.
ESPs need a `Level Shifter <https://www.adafruit.com/product/1875>`__ to be compatible with TTL levels.
..note::
You need a IC level shifter and not a `Mosfet-based <https://www.sparkfun.com/products/12009>`__ level shifter, because you need
to power the optocoupler's LEDs without an additional resistor in the path.
If prefer, you could change the value of the optocoupler's resistors by following `this <https://gregwareblog.wordpress.com/2020/12/13/home-power-monitoring-pzem-004/>`__ or `this <https://www.instructables.com/Power-Peacefair-PZEM-004-ESP8266-Arduino-Nano/>`__ guide.
Your ESP shall be powered by an external power supply and cannot be connected to the PZEM for power.