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 can measure voltage, current, power, energy consumption, and frequency, making it an essential tool for energy management and monitoring systems. The module communicates via a UART (serial) interface, enabling seamless integration with microcontrollers such as the Arduino UNO.

• Home energy monitoring systems
• Industrial equipment monitoring
• Renewable energy systems (e.g., solar inverters)
• Smart IoT-based energy management solutions
• Laboratory and educational projects

Below are the key technical details of the PZEM-004T module:

The PZEM-004T module has the following pinout:

1. Power the Module: Connect the VCC and GND pins of the PZEM-004T to a 5V DC power source.
2. Connect the UART Interface:
   • 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.
3. Connect the AC Circuit:
   • Attach the live and neutral wires of the AC circuit to the AC input terminals of the PZEM-004T.
   • Place the external current transformer (CT) around the live wire of the AC circuit.
4. Load the Arduino Code: Use the provided Arduino code to read data from the PZEM-004T.

• Ensure proper isolation between the AC circuit and the low-voltage side of the module to avoid electrical hazards.
• Use a high-quality current transformer (CT) for accurate current measurements.
• Avoid exceeding the voltage and current measurement limits of the module.
• Use a pull-up resistor on the UART lines if communication issues occur.

Below is an example Arduino sketch to interface the PZEM-004T with an Arduino UNO:

#include <PZEM004Tv30.h> // Include the PZEM-004T library

// Define the RX and TX pins for the PZEM-004T
#define RX_PIN 10
#define TX_PIN 11

// Create a PZEM object using the defined RX and TX pins
PZEM004Tv30 pzem(RX_PIN, TX_PIN);

void setup() {
  Serial.begin(9600); // Initialize serial communication for debugging
  Serial.println("PZEM-004T Energy Meter Example");
}

void loop() {
  // Read voltage
  float voltage = pzem.voltage();
  if (!isnan(voltage)) {
    Serial.print("Voltage: ");
    Serial.print(voltage);
    Serial.println(" V");
  } else {
    Serial.println("Error reading voltage!");
  }

  // Read current
  float current = pzem.current();
  if (!isnan(current)) {
    Serial.print("Current: ");
    Serial.print(current);
    Serial.println(" A");
  } else {
    Serial.println("Error reading current!");
  }

  // Read power
  float power = pzem.power();
  if (!isnan(power)) {
    Serial.print("Power: ");
    Serial.print(power);
    Serial.println(" W");
  } else {
    Serial.println("Error reading power!");
  }

  // Read energy
  float energy = pzem.energy();
  if (!isnan(energy)) {
    Serial.print("Energy: ");
    Serial.print(energy);
    Serial.println(" kWh");
  } else {
    Serial.println("Error reading energy!");
  }

  // Read frequency
  float frequency = pzem.frequency();
  if (!isnan(frequency)) {
    Serial.print("Frequency: ");
    Serial.print(frequency);
    Serial.println(" Hz");
  } else {
    Serial.println("Error reading frequency!");
  }

  delay(2000); // Wait for 2 seconds before the next reading
}

1. No Data Received from the Module:

   • Ensure the RX and TX pins are correctly connected between the PZEM-004T and the Arduino UNO.
   • Verify that the baud rate is set to 9600 in the Arduino code.

2. Incorrect Voltage or Current Readings:

   • Check the connections to the AC input and the current transformer (CT).
   • Ensure the CT is properly clamped around the live wire of the AC circuit.

3. Communication Errors:

   • Use shorter wires for the UART connection to reduce noise.
   • Add pull-up resistors to the RX and TX lines if necessary.

4. Module Not Powering On:

   • Verify that the VCC pin is receiving a stable 5V DC supply.
   • Check for loose or faulty connections.

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 module can measure?
A: The module can measure up to 100A when used with the appropriate current transformer (CT).

Q: Can I use multiple PZEM-004T modules with a single Arduino?
A: Yes, you can use multiple modules by assigning different UART pins for each module or using a multiplexer.

Q: Is the module safe to use with high-voltage AC circuits?
A: Yes, but proper isolation and safety precautions must be followed to prevent electrical hazards.