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 with high accuracy. The module communicates via UART (Universal Asynchronous Receiver-Transmitter), making it easy to integrate with microcontrollers and other devices.

This component is widely used in energy monitoring systems, smart home applications, industrial automation, and other projects requiring real-time electrical parameter tracking.

The PZEM-004T has the following key technical specifications:

The PZEM-004T module has a simple pinout for easy integration. Below is the pin configuration:

Note: The module comes with an external current transformer (CT) for current measurement. Ensure the CT is properly connected to the load for accurate readings.

1. Power Supply: Connect the VCC pin to a 5V DC power source and the GND pin to ground.
2. UART Communication: Connect the TX pin of the PZEM-004T to the RX pin of your microcontroller (e.g., Arduino UNO) and the RX pin of the PZEM-004T to the TX pin of the microcontroller.
3. AC Input: Connect the live and neutral wires of the AC circuit to the AC input terminals of the module.
4. Current Transformer: Place the external CT around the live wire of the load you want to measure. Ensure the CT is oriented correctly as per the markings.
5. Software Integration: Use the UART interface to send commands and receive data from the module. Libraries are available for platforms like Arduino to simplify communication.

• Safety First: The PZEM-004T operates with high-voltage AC circuits. Ensure proper insulation and safety precautions while handling the module.
• Current Transformer Placement: The CT should only enclose the live wire, not both live and neutral wires, to measure current accurately.
• Baud Rate: The default UART baud rate is 9600. Ensure your microcontroller is configured to communicate at this rate.
• Isolation: For added safety, consider using optocouplers or isolation circuits when interfacing with microcontrollers.

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

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

// Define the RX and TX pins for UART communication
#define RX_PIN 10
#define TX_PIN 11

// Create a PZEM object with the specified 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!");
  }

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

Note: Install the PZEM004Tv30 library in the Arduino IDE before uploading the code. You can find it in the Library Manager.

1. No Data Received from the Module:

   • Ensure the TX and RX pins are correctly connected (crossed: TX to RX and RX to TX).
   • Verify the baud rate is set to 9600 in your microcontroller code.
   • Check the power supply to the module (5V DC).

2. Incorrect Current or Power Readings:

   • Ensure the current transformer (CT) is properly placed around the live wire.
   • Verify that the CT is not damaged or improperly connected.

3. Module Not Responding:

   • Check the wiring for loose connections.
   • Ensure the AC input is within the specified voltage range (80V - 260V AC).

4. Error Messages in Arduino Serial Monitor:

   • Ensure the PZEM-004T library is correctly installed.
   • Double-check the UART connections and ensure no other devices are interfering with the communication.

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

Q: Is it possible to reset the energy reading?
A: Yes, the energy reading can be reset via a specific UART command. Refer to the module's datasheet for details.

Q: Can I use multiple PZEM-004T modules with one microcontroller?
A: Yes, you can use multiple modules by assigning unique addresses to each module via UART commands.

Q: What is the maximum distance for UART communication?
A: The maximum reliable distance for UART communication depends on the baud rate and cable quality, but it is typically around 15 meters.

By following this documentation, you can effectively integrate and use the PZEM-004T energy meter in your projects.