How to Use pzem-004t: Examples, Pinouts, and Specs

The PZEM-004T is a multifunctional energy meter designed for monitoring and measuring key electrical parameters in AC circuits. It provides real-time data on voltage, current, power, energy consumption, frequency, and power factor. This module communicates via UART (Universal Asynchronous Receiver-Transmitter), making it easy to interface with microcontrollers such as the Arduino UNO (manufacturer part ID: UNO).

• Home energy monitoring systems
• Industrial equipment monitoring
• Smart home automation
• Data logging for energy consumption analysis
• Power quality monitoring in AC circuits

The PZEM-004T is a compact and efficient energy meter with the following key specifications:

The PZEM-004T module has a simple pinout for easy integration:

1. Connect the Voltage Input:

   • Connect the V+ pin to the live wire of the AC circuit.
   • Connect the V- pin to the neutral wire of the AC circuit.

2. Connect the Current Transformer (CT):

   • Place the CT around the live wire of the AC circuit to measure current.
   • Ensure the CT is oriented correctly (arrow on the CT should point toward the load).

3. Connect to a Microcontroller:

   • Connect the TX pin of the PZEM-004T to the RX pin of the Arduino UNO.
   • Connect the RX pin of the PZEM-004T to the TX pin of the Arduino UNO.
   • Connect the GND pin of the PZEM-004T to the GND of the Arduino UNO.

4. Power the Module:

   • The PZEM-004T is self-powered from the AC line, so no external power supply is needed.

• Safety First: Always handle the PZEM-004T with care when working with high-voltage AC circuits. Ensure all connections are insulated and secure.
• Common Ground: Ensure the PZEM-004T and the microcontroller share a common ground for proper UART communication.
• Baud Rate: The default UART baud rate is 9600. Ensure your microcontroller is configured to match this setting.
• Current Transformer Placement: The CT should only enclose the live wire, not both live and neutral wires, to measure current correctly.

Below is an example Arduino sketch to read data from the PZEM-004T:

#include <SoftwareSerial.h>

// Define RX and TX pins for SoftwareSerial
SoftwareSerial pzemSerial(10, 11); // RX = pin 10, TX = pin 11

void setup() {
  Serial.begin(9600); // Initialize Serial Monitor
  pzemSerial.begin(9600); // Initialize PZEM-004T communication

  Serial.println("PZEM-004T Energy Meter Example");
}

void loop() {
  // Request data from PZEM-004T
  byte request[] = {0x01, 0x04, 0x00, 0x00, 0x00, 0x0A, 0x70, 0x0D};
  pzemSerial.write(request, sizeof(request));

  delay(100); // Wait for response

  // Read response from PZEM-004T
  byte response[25];
  int len = pzemSerial.readBytes(response, 25);

  if (len > 0) {
    Serial.print("Response: ");
    for (int i = 0; i < len; i++) {
      Serial.print(response[i], HEX);
      Serial.print(" ");
    }
    Serial.println();
  } else {
    Serial.println("No response from PZEM-004T");
  }

  delay(1000); // Wait 1 second before next request
}

• The SoftwareSerial library is used to communicate with the PZEM-004T on pins 10 and 11 of the Arduino UNO.
• The example sends a Modbus RTU request to the PZEM-004T and prints the raw response to the Serial Monitor.
• For detailed data parsing, refer to the PZEM-004T Modbus protocol documentation.

1. No Response from the PZEM-004T:

   • Ensure the UART connections (TX, RX, and GND) are correct.
   • Verify that the baud rate is set to 9600 in your code.
   • Check that the PZEM-004T is properly connected to the AC circuit.

2. Incorrect Readings:

   • Ensure the current transformer (CT) is properly placed around the live wire.
   • Verify that the voltage input connections (V+ and V-) are secure.

3. Communication Errors:

   • Ensure the microcontroller and PZEM-004T share a common ground.
   • Check for electrical noise or interference in the circuit.

Q: Can the PZEM-004T measure DC circuits?
A: No, the PZEM-004T is designed specifically for AC circuits and cannot measure DC voltage or current.

Q: What is the maximum current the PZEM-004T can measure?
A: The PZEM-004T can measure up to 100A using the included current transformer.

Q: Can I use multiple PZEM-004T modules with one Arduino?
A: Yes, you can use multiple modules by assigning unique Modbus addresses to each PZEM-004T and connecting them to the same UART bus.

Q: Is the PZEM-004T safe to use with high-voltage circuits?
A: Yes, but always follow proper safety precautions and ensure all connections are insulated to prevent electric shock.

This concludes the documentation for the PZEM-004T energy meter. For further assistance, refer to the manufacturer's datasheet or support resources.