Using Multiple PZEM-004T Devices with a Single Pair of RX/TX Pins

3 Phase Energy Monitoring using 3 PZEM 004-T and nodemcu (esp8266)

Most simple setup (No Resistor and No Diode mod required)

Using weemos d1 mini in this configuration is not recomended

This guide will help you set up multiple PZEM-004T devices using a single pair of RX and TX pins on a NodeMCU ESP8266 board. It uses ESPHome to communicate with the devices and send the data to Home Assistant.

Prerequisites

• NodeMCU ESP8266 board
• One or more PZEM-004T devices
• Home Assistant installed and configured

Schematics

Assign Unique Addresses to Each PZEM-004T Device

1. Ensure that only one PZEM-004T device is connected to the UART bus at a time.
2. Load the change-address.yaml file for each PZEM-004T device.
3. Set the new_address variable to a unique value between 0x01 and 0xF7.
4. Flash the firmware to the NodeMCU ESP8266 board and let it boot.
5. After the boot, check for a log containing PZEM Addr set.
6. Repeat these steps for each PZEM device.

Suggestion: Write down the updated address on the yellow portion of the PZEM; this will make your life much easier later.

Suggestion: Avoid using the 0x01 address, as new devices have that address by default. When you add new devices later, it will be much easier to manage the addresses.

Finalizing the Setup

1. Load the code in the power-meter.yaml file in your ESPHome for the device.
2. Change the addresses in the configuration to match your PZEM-004T device addresses.
3. Flash the code to your NodeMCU ESP8266 or ESP32 board.
4. Enjoy detailed data on your power consumption habits through Home Assistant.