How to Use PZEM004T.V4-2: Examples, Pinouts, and Specs

The PZEM004T.V4-2, manufactured by Peacefair, is a multifunctional energy meter designed for monitoring and managing energy consumption in AC circuits. This compact module measures key electrical parameters, including voltage, current, power, energy, and frequency, and provides real-time data via a digital display or UART communication interface. Its versatility makes it ideal for applications such as home energy monitoring, industrial equipment diagnostics, and renewable energy systems.

• Home energy monitoring systems
• Industrial equipment diagnostics
• Renewable energy systems (e.g., solar inverters)
• Smart energy management solutions
• Educational and research projects

The PZEM004T.V4-2 module has a 4-pin interface for UART communication and power connections. Below is the pinout description:

1. Power Supply: Connect the VCC pin to a 5V DC power source and the GND pin to ground.
2. UART Communication: Connect the RX pin of the module to the TX pin of your microcontroller (e.g., Arduino UNO) and the TX pin of the module to the RX pin of the microcontroller.
3. Current Transformer (CT): Attach the included current transformer (CT) to the load wire you wish to monitor. Ensure the CT is properly oriented for accurate readings.
4. AC Voltage Input: Connect the AC voltage input terminals to the live and neutral wires of the circuit you want to monitor. Exercise caution when handling high-voltage connections.

• Safety First: Always disconnect power before wiring the module to avoid electric shock.
• CT Placement: Ensure the current transformer is clamped around only one conductor (live or neutral) and not both.
• UART Communication: Use a logic level converter if interfacing with a 3.3V microcontroller to avoid damaging the module.
• Baud Rate: The default UART baud rate is 9600. Ensure your microcontroller is configured to match this.

Below is an example Arduino sketch to read data from the PZEM004T.V4-2 module:

#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 communication with PZEM004T

  Serial.println("PZEM004T.V4-2 Energy Meter Example");
}

void loop() {
  // Request data from the PZEM004T module
  byte request[] = {0xB0, 0xC0, 0xA8, 0x01, 0x01, 0x01, 0x00, 0x1A};
  pzemSerial.write(request, sizeof(request));

  delay(100); // Wait for the module to respond

  // Read response from the module
  byte response[32];
  int len = pzemSerial.readBytes(response, sizeof(response));

  if (len > 0) {
    Serial.print("Received Data: ");
    for (int i = 0; i < len; i++) {
      Serial.print(response[i], HEX);
      Serial.print(" ");
    }
    Serial.println();
  } else {
    Serial.println("No response from PZEM004T");
  }

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

Note: The above code demonstrates basic communication with the module. For detailed data parsing, refer to the PZEM004T.V4-2 protocol documentation.

1. No Data Received via UART

   • Cause: Incorrect wiring or mismatched baud rate.
   • Solution: Double-check the RX/TX connections and ensure the baud rate is set to 9600.

2. Inaccurate Measurements

   • Cause: Improper CT placement or loose connections.
   • Solution: Ensure the CT is clamped around a single conductor and verify all connections are secure.

3. Module Not Powering On

   • Cause: Insufficient power supply.
   • Solution: Verify the VCC pin is receiving a stable 5V DC supply.

4. High Noise in Readings

   • Cause: Electrical noise in the circuit.
   • Solution: Use proper shielding and grounding techniques to minimize noise.

Q1: Can the PZEM004T.V4-2 measure DC circuits?
No, the module is designed specifically for AC circuits and cannot measure DC voltage or current.

Q2: What is the maximum current the module can measure?
The module can measure up to 100A using the included current transformer.

Q3: Can I use the module with a 3.3V microcontroller?
Yes, but you must use a logic level converter to safely interface the 5V UART pins with a 3.3V microcontroller.

Q4: How do I reset the energy counter?
The energy counter can be reset via a specific UART command. Refer to the protocol documentation for details.

This concludes the documentation for the PZEM004T.V4-2 energy meter. For further assistance, consult the manufacturer's datasheet or contact Peacefair support.